Professor David J. Blackbourn

Head of the School of Biosciences and Medicine
15 AX 01
PA: Jane Steele
+44 (0)1483 686920


Previous roles

Head of Department of Microbial and Cellular Sciences
University of Surrey
Honorary Senior Research Fellow
School of Cancer Sciences, University of Birmingham
Professor of Virology
University of Birmingham
Reader in Tumour Virology
University of Birmingham
Reader in Virology
Institute of Virology, University of Glasgow
2003 - 2005
Senior Lecturer in Virology
Institute of Virology, University of Glasgow
1999 - 2003
Lecturer in Virology
Institute of Virology, University of Glasgow
1997 - 1999
Staff Scientist
Department of Medicine, University of California
1993 - 1997
Post-doctoral Researcher, Jay A. Levy, M.D.
Department of Medicine, University of California
1990 - 1992
Post-doctoral Researcher, Ronald Chuang, PhD.
Department of Medicine, Pharmacology and Toxicology, University of California


Research interests

Research collaborations

My publications


Publications from the last five years:

McKimmie, C.S., M.D. Singh, K. Hewit, O. Franco-Lopez, M. Le Broq, S. Rose-John, A.H. Baker, R. Wheat, D.J. Blackbourn, R.J.B. Nibbs and G.J. Graham. An analysis of the function and expression of D6 on lymphatic endothelial cells. Blood, 121: 3768-3777. 2013

Jacobs, S.R., S.M. Gregory, J.A. West, A.C. Wollish, D.J. Blackbourn, M.T. Heise and B. Damania. The KSHV vIRFs inhibit interferon activation mediated by TLR3. J. Virol. 87: 798-806, 2013.

Damania, B and D.J. Blackbourn. Innate Barriers to Viral Infection. Future Microbiology 7:815-822, 2012. Butler, L.M., H.C. Jeffery, R.L. Wheat RL, P.C. Rae, H.M. Long, G.B. Nash & D.J. Blackbourn. KSHV inhibits expression and function of endothelial cell MHC class II via suppressor of cytokine signalling 3. J.Virol. 86: 7158-7166, 2012.

Misstear, K., S.A. Chanas, S.A.R. Rezaee, R. Colman, A.S. Solovyova, L.L. Quinn, H.M. Long, J.M. Lord, J.A. Gracie, I.B. McInnes, A.D. Hislop and D.J. Blackbourn. Suppression of antigen-specific T cell responses by the KSHV vOX2 protein and its cellular orthologue, CD200. J.Virol. 86: 6246-6257, 2012.

Berhane, S., C. Aresté, J. Ablack, G. Ryan, D.J. Blackbourn, J.S. Mymryk, A.S. Turnell, J.C. Steele & R.J.A. Grand. Adenovirus E1A interacts directly with, and regulates the level of expression of, the immunoproteasome component MECL1. Virology, 421: 149-158, 2011.

Mutocheluh, M., L. Hindle, C. Aresté, S.A. Chanas, L.M. Butler, K. Lowry, K. Shah, D.J. Evans & D.J. Blackbourn. KSHV vIRF-2 inhibits type 1 interferon signalling by targeting ISGF-3. J. Gen. Virol., 92: 2394-8, 2011.

Jackson, B.R., J.R. Boyne, M. Noerenberg, A. Taylor, G.M. Hautbergue, M.J. Walsh, R. Wheat, D.J. Blackbourn, S.A. Wilson, A. Whitehouse. An interaction between KSHV ORF57 and UIF provides mRNA-adaptor redundancy in herpesvirus intronless mRNA export. PLoS Pathog. 2011 Jul;7(7):e1002138. Epub 2011 Jul 21.

Butler L.M., H.C. Jeffery, R.L. Wheat, P.C. Rae, K. Townsend, K.R. Alkharsah, T.F. Schulz, G.B. Nash and D.J. Blackbourn. KSHV inhibits neutrophil recruitment through an IL-6 dependent mechanism - a new paradigm for viral immune evasion. J. Virol. 85: 7321-7332, 2011.

Taylor, G.S. and D.J. Blackbourn. Immunomodulation by infectious agents in human cancers: Lessons from gammaherpesviruses EBV and KSHV. Cancer Letters 305: 263-278, 2011.

Durrington, H.J., P.D. Upton, S. Hoer, J. Boname, B. Dunmore, J. Yang, T.K. Crilley, L.M. Butler, D.J. Blackbourn, G.B. Nash, P.J. Lehner, N.W. Morrell. Identification of a lysosomal pathway regulating degradation of the bone morphogenetic protein receptor type-II. J. Biol. Chem. 285: 37641-49, 2010.

Aresté, C., M. Mutocheluh, M. and D.J. Blackbourn. Identification of Caspase-mediated Decay of Interferon Regulatory Factor-3, Exploited by a Kaposi Sarcoma-associated Herpesvirus Immunoregulatory Protein. J. Biol. Chem. 284: 23272-85, 2009.

Aresté, C. and Blackbourn, D.J. Modulation of the immune system by Kaposi's sarcoma-associated herpesvirus. Trends in Microbiology. 17:119-129, 2009.

Wang, L., M. Pietrek, M. Brinkmann, A. Hävemeier, I. Fischer, B. Hillenbrand, O. Dittrich-Breiholz, M. Kracht , S. Chanas, D.J. Blackbourn and T.F. Schulz. Identification and functional characterization of a spliced Rhesus Rhadinovirus gene with homology to the K15 gene of Kaposi's sarcoma-associated herpesvirus. J. Gen. Virol. 90:1190-1201, 2009.

Okroj, M., L. Mark, A. Stokowska, S.W. Wong, D.J. Blackbourn, O.B. Spiller, A. Blom. Characterization of the complement inhibitory function of Rhesus Rhadinovirus complement control protein (RCP). J. Biol. Chem. 284:505-514, 2009.

Mark, L., D.G. Proctor, D.J. Blackbourn, A.M. Blom, O.B. Spiller. Separation of decay-accelerating and cofactor functional activities of KSHV complement control protein (KCP) using monoclonal antibodies. Immunology. 123:228-38, 2008.

Colman, R. and D.J. Blackbourn. Cofactors in KS Development. AIDS. 22:1629-32, 2008.


Patrick W. Narkwa, David Blackbourn, Mohamed Mutocheluh (2017)Aflatoxin B1 inhibits the type 1 interferon response pathway via STAT1 suggesting another mechanism of hepatocellular carcinoma, In: Infectious Agents and Cancer12(17) BioMed Central

Background Aflatoxin B1 (AFB1) contamination of food is very high in most sub-Saharan African countries. AFB1 is known to cause hepatocellular carcinoma (HCC) by inducing mutation in the tumour suppressor gene TP53. The number of new HCC cases is high in West Africa with an accompanying high mortality. The type I interferon (IFN) pathway of the innate immune system limits viral infections and exerts its anti-cancer property by up-regulating tumour suppressor activities and pro-apoptotic pathways. Indeed, IFN-α is reported to show significant protective effects against hepatic fibrogenesis and carcinogenesis. However, the mechanism behind AFB1 deregulation of the type I interferon (IFN) signalling pathway, with consequent HCC is largely unknown. This current study seeks to test the hypothesis that AFB1 inhibits the type I IFN response by directly interfering with key signalling proteins and thus increase the risk of HCC in humans. Methods We evaluated the effects of AFB1 on the type I IFN signalling pathway using IFN stimulated response element (ISRE)-based luciferase reporter gene assay. In addition, the effects of AFB1 on the transcript levels of JAK1, STAT1 and OAS3 were assessed by real-time quantitative polymerase chain reaction (RT-qPCR) and confirmed by immunoblot assay. Results Our results indicated that AFB1 inhibited the type I IFN signalling pathway in human hepatoma cell line HepG2 cells by suppressing the transcript levels of JAK1, STAT1 and OAS3. AFB1 also decreased the accumulation of STAT1 protein. Conclusion The inhibition of the type I IFN anti-cancer response pathway by AFB1 suggest a novel mechanism by which AFB1 may induce hepatocellular carcinoma in humans.

K Misstear, SA Chanas, SA Rezaee, R Colman, LL Quinn, HM Long, O Goodyear, JM Lord, AD Hislop, DJ Blackbourn (2012)Suppression of antigen-specific T cell responses by the Kaposi's sarcoma-associated herpesvirus viral OX2 protein and its cellular orthologue, CD200., In: J Virol86(11)pp. 6246-6257

Regulating appropriate activation of the immune response in the healthy host despite continual immune surveillance dictates that immune responses must be either self-limiting and therefore negatively regulated following their activation or prevented from developing inappropriately. In the case of antigen-specific T cells, their response is attenuated by several mechanisms, including ligation of CTLA-4 and PD-1. Through the study of the viral OX2 (vOX2) immunoregulator encoded by Kaposi's sarcoma-associated herpesvirus (KSHV), we have identified a T cell-attenuating role both for this protein and for CD200, a cellular orthologue of the viral vOX2 protein. In vitro, antigen-presenting cells (APC) expressing either native vOX2 or CD200 suppressed two functions of cognate antigen-specific T cell clones: gamma interferon (IFN-γ) production and mobilization of CD107a, a cytolytic granule component and measure of target cell killing ability. Mechanistically, vOX2 and CD200 expression on APC suppressed the phosphorylation of ERK1/2 mitogen-activated protein kinase in responding T cells. These data provide the first evidence for a role of both KSHV vOX2 and cellular CD200 in the negative regulation of antigen-specific T cell responses. They suggest that KSHV has evolved to harness the host CD200-based mechanism of attenuation of T cell responses to facilitate virus persistence and dissemination within the infected individual. Moreover, our studies define a new paradigm in immune modulation by viruses: the provision of a negative costimulatory signal to T cells by a virus-encoded orthologue of CD200.

B Damania, DJ Blackbourn (2012)Innate barriers to viral infection., In: Future Microbiol7(7)pp. 815-822

Innate immunity represents the foremost barrier to viral infection. In order to infect a cell efficiently, viruses need to evade innate immune effectors such as interferons and inflammatory cytokines. Pattern recognition receptors can detect viral components or pathogen-associated molecular patterns. These receptors then elicit innate immune responses that result in the generation of type I interferons and proinflammatory cytokines. Organized by the Society for General Microbiology, one session of this conference focused on the current state-of-the-art knowledge on innate barriers to infection of different RNA and DNA viruses. Experts working on innate immunity in the context of viral infection provided insight into different aspects of innate immune recognition and also discussed areas for future research. Here, we provide an overview of the session on innate barriers to infection.

M Mutocheluh, L Hindle, C Aresté, SA Chanas, LM Butler, K Lowry, K Shah, DJ Evans, DJ Blackbourn (2011)Kaposi's sarcoma-associated herpesvirus viral interferon regulatory factor-2 inhibits type 1 interferon signalling by targeting interferon-stimulated gene factor-3., In: J Gen Virol92(Pt 10)pp. 2394-2398

Kaposi's sarcoma-associated herpesvirus (KSHV) encodes four viral interferon regulatory factors (vIRF-1-4). We investigated the mechanism and consequences of vIRF-2-mediated inhibition of interferon-response element signalling following type I interferon (IFN) induction. Western blot and electrophoretic mobility-shift assays identified the interferon-stimulated gene factor-3 (ISGF-3) components STAT1 and IRF-9 as the proximal targets of vIRF-2 activity. The biological significance of vIRF-2 inhibition of ISGF-3 was demonstrated by vIRF-2-mediated rescue of the replication of the IFN-sensitive virus encephalomyocarditis virus. This study provides both a mechanism and evidence for KSHV vIRF-2-mediated suppression of the consequences of type 1 IFN-induced signalling.

Andrea L. Darling, David J. Blackbourn, Kourosh R. Ahmadi, Susan A. Lanham-New (2020)Very High Prevalence of 25-hydroxyvitamin D Deficiency in n 6433 UK South Asian adults: analysis of the UK Biobank Cohort, In: British Journal of Nutritionpp. 1-34 Cambridge University Press

Little research has assessed serum 25-hydroxyvitamin D (25(OH)D) concentration and its predictors in western dwelling South Asians in a relatively large sample size. This observational, cross-sectional analysis assessed baseline prevalence of 25(OH)D deficiency in UK dwelling South Asians (aged 40-69 years, 2006-2010) from the UK Biobank cohort. Serum 25(OH)D measurements were undertaken using the DiaSorin Liaison XL assay. Of n 6433 South Asians with a 25(OH)D measurement, using commonly used cut-off thresholds, 55% (n 3538) had 25(OH)D

AA Amini, AS Solovyova, H Sadeghian, DJ Blackbourn, SAR Rezaee (2015)Structural properties of a viral orthologue of cellular CD200 protein: KSHV vOX2, In: VIROLOGY474pp. 94-104 ACADEMIC PRESS INC ELSEVIER SCIENCE
SR Jacobs, SM Gregory, JA West, AC Wollish, CL Bennett, DJ Blackbourn, MT Heise, B Damania (2013)The Viral Interferon Regulatory Factors of Kaposi's Sarcoma-Associated Herpesvirus Differ in Their Inhibition of Interferon Activation Mediated by Toll-Like Receptor 3, In: JOURNAL OF VIROLOGY87(2)pp. 798-806 AMER SOC MICROBIOLOGY
S Fuld, C Cunningham, K Klucher, AJ Davison, DJ Blackbourn (2006)Inhibition of interferon signaling by the Kaposi's sarcoma-associated herpesvirus full-length viral interferon regulatory factor 2 protein, In: JOURNAL OF VIROLOGY80(6)pp. 3092-3097 AMER SOC MICROBIOLOGY
R Hollingworth, GL Skalka, GS Stewart, AD Hislop, DJ Blackbourn, RJ Grand (2015)Activation of DNA Damage Response Pathways during Lytic Replication of KSHV, In: VIRUSES-BASEL7(6)pp. 2908-2927 MDPI AG
L Mark, OB Spiller, M Okroj, S Chanas, JA Aitken, SW Wong, B Damania, AM Blom, DJ Blackbourn (2007)Molecular characterization of the rhesus rhadinovirus (RRV) ORF4 gene and the RRV complement control protein it encodes, In: JOURNAL OF VIROLOGY81(8)pp. 4166-4176 AMER SOC MICROBIOLOGY
S Berhane, C Aresté, JN Ablack, GB Ryan, DJ Blackbourn, JS Mymryk, AS Turnell, JC Steele, RJ Grand (2011)Adenovirus E1A interacts directly with, and regulates the level of expression of, the immunoproteasome component MECL1., In: Virology421(2)pp. 149-158

Proteasomes represent the major non-lysosomal mechanism responsible for the degradation of proteins. Following interferon γ treatment 3 proteasome subunits are replaced producing immunoproteasomes. Adenovirus E1A interacts with components of the 20S and 26S proteasome and can affect presentation of peptides. In light of these observations we investigated the relationship of AdE1A to the immunoproteasome. AdE1A interacts with the immunoproteasome subunit, MECL1. In contrast, AdE1A binds poorly to the proteasome β2 subunit which is replaced by MECL1 in the conversion of proteasomes to immunoproteasomes. Binding sites on E1A for MECL1 correspond to the N-terminal region and conserved region 3. Furthermore, AdE1A causes down-regulation of MECL1 expression, as well as LMP2 and LMP7, induced by interferon γ treatment during Ad infections or following transient transfection. Consistent with previous reports AdE1A reduced IFNγ-stimulated STAT1 phosphorylation which appeared to be responsible for its ability to reduce expression of immunoproteasome subunits.

HJ Durrington, PD Upton, S Hoer, J Boname, BJ Dunmore, J Yang, TK Crilley, LM Butler, DJ Blackbourn, GB Nash, PJ Lehner, NW Morrell (2010)Identification of a Lysosomal Pathway Regulating Degradation of the Bone Morphogenetic Protein Receptor Type II, In: JOURNAL OF BIOLOGICAL CHEMISTRY285(48)pp. 37641-37649 AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
C Areste, M Mutocheluh, DJ Blackbourn (2009)Identification of Caspase-mediated Decay of Interferon Regulatory Factor-3, Exploited by a Kaposi Sarcoma-associated Herpesvirus Immunoregulatory Protein, In: JOURNAL OF BIOLOGICAL CHEMISTRY284(35)pp. 23272-23285 AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
Christopher P Locher, David J Blackbourn, Susan W Barnett, Krishna K Murthy, Elizabeth K Cobb, Scott Rouse, Giampaolo Greco, Gustavo Reyes-Terán, Kathleen M Brasky, Kenneth D Carey, Jay A Levy (1997)Superinfection with Human Immunodeficiency Virus Type 2 Can Reactivate Virus Production in Baboons but Is Contained by a CD8 T Cell Antiviral Response, In: The Journal of infectious diseases176(4)pp. 948-959 The University of Chicago Press

An animal model was used to assess whether resistance to superinfection by human immunodeficiency virus (HIV) can exist in vivo. Asymptomatic baboons (Papio cynocephalus), previously infected with HIV-2, were first challenged with homologous virus (HIV-2UC2 or HIV-2UC14) and later with heterologous virus (HIV-2UC12). After both virus inoculations, either resistance to viral infection or a transient viremia was observed. The original virus was recovered in 3 baboons, suggesting that reactivation of a latent infection occurred on heterologous challenge and that HIV-2 superinfection is blocked by processes established during prior infection. Antibody titers measured by ELISA and virus neutralization remained at low levels. However, suppression of HIV-1 replication was observed with CD8 T cells and filtered cell culture supernatants. The soluble factor involved was not a β-chemokine. This resistance to HIV superinfection appears to be mediated at least in part by CD8 T cells that suppress virus production.

L F Chuang, D J Blackbourn, A J Chuang, K F Killam, Jr, X Liu, Y Li, H F Kung, R Y Chuang (1994)Emergence of antigenic variants of simian immunodeficiency virus (SIVmac) in a seronegative macaque after SIVmac239 infection, In: Cellular & molecular biology research40(7-8)pp. 661-669

Infection with the macaque strain of the simian immunodeficiency virus (SIVmac) induces simian immunodeficiency syndrome in rhesus macaques. This report describes the isolation and identification of antigenic variants of SIVmac in one of the infected monkeys (macaque #22803). Eight naive rhesus monkeys were inoculated with a titered viral stock of the molecularly cloned SIVmac239. Standard serological analysis revealed that all but two were seroconverted. Western blot analysis confirmed the seronegativity of macaque #22803. In addition, sera recovered from this monkey were not able to neutralize the parent SIVmac239. However, virus could be isolated from all of the infected animals, including macaque #22803. Sera recovered were reactive to the autologous virus. The results suggest that the virus from macaque #22803 may have undergone extensive antigenic shift in vivo. To test this hypothesis, a portion of the gag gene was amplified by the polymerase chain reaction (PCR), cloned, and sequenced. Sequence analysis revealed amino acid changes that were clustered between amino acids 200-245. Evaluation of the possible selective pressures contributing to the observed viral mutation revealed that in comparison with the other SIVmac239-infected monkeys, macaque #22803 produced an unusually high T cell proliferative response toward mitogen stimulation before infection, and continued to display a persistently high plasma viremia titer after infection.

C P Locher, K F Sykes, D J Blackbourn, S A Johnston (2002)Immune responses in baboons vaccinated with HIV-2 genetic expression libraries, In: Journal of medical primatology31(6)pp. 323-329

Immunization using genetic expression libraries may be an improvement over conventional DNA immunization using a single gene because more epitopes are simultaneously presented to the immune system. In this study, we evaluated the effectiveness of an HIV-2 vaccine made from a genomic expression library in baboons. We found that HIV-2 expression library immunization induced HIV-2-specific memory responses but low levels of CD8+ cell anti-viral responses and neutralizing antibodies. After intravenous virus challenge using a homologous pathogenic variant, HIV-2UC2/9429, viral loads were similar in the HIV-2-immunized and control baboons. We conclude that although immunization using HIV-2 expression libraries induces immune responses, this approach does not provide protection in baboons against intravenous challenge with HIV-2.

C P Locher, S W Barnett, B G Herndier, D J Blackbourn, G Reyes-Terán, K K Murthy, K M Brasky, G B Hubbard, T A Reinhart, A T Haase, J A Levy (1998)Human immunodeficiency virus-2 infection in baboons is an animal model for human immunodeficiency virus pathogenesis in humans, In: Archives of pathology & laboratory medicine (1976)122(6)pp. 523-533

To assess disease progression in baboons (Papio cynocephalus) that were infected with two human immunodeficiency virus-2 (HIV-2) isolates. Eight baboons were inoculated intravenously with either HIV-2UC2 or HIV-2UC14 and were followed for a 2- to 7-year period of observation. Six of 8 baboons showed lymphadenopathy and other signs of HIV-related disease, 3 of 8 baboons had an acute phase CD4+ T-cell decline, and 2 of 5 baboons infected with the HIV-2UC2 isolate progressed to an acquired immunodeficiency syndrome-like disease. Human immunodeficiency virus-2-specific pathology in lymphatic tissues included follicular lysis, vascular proliferation, and lymphoid depletion. Both neutralizing antibodies and a CD8+ T-cell antiviral response were associated with resistance to disease. Disease progression and the development of acquired immunodeficiency syndrome in HIV-2-infected baboons have similarities to human HIV infections.

O. Brad Spiller, Mairi Robinson, Elizabeth O'Donnell, Steven Milligan, B. Paul Morgan, Andrew J Davison, David J Blackbourn (2003)Complement Regulation by Kaposi's Sarcoma-Associated Herpesvirus ORF4 Protein, In: Journal of virology77(1)pp. 592-599 American Society for Microbiology

Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with three types of human tumor: Kaposi's sarcoma, multicentric Castleman's disease, and primary effusion lymphoma. The virus encodes a number of proteins that participate in disrupting the immune response, one of which was predicted by sequence analysis to be encoded by open reading frame 4 (ORF4). The predicted ORF4 protein shares homology with cellular proteins referred to as regulators of complement activation. In the present study, the transcription profile of the ORF4 gene was characterized, revealing that it encodes at least three transcripts, by alternative splicing mechanisms, and three protein isoforms. Functional studies revealed that each ORF4 protein isoform inhibits complement and retains a C-terminal transmembrane domain. Consistent with the complement-regulating activity, we propose to name the proteins encoded by the ORF4 gene collectively as KSHV complement control protein (KCP). KSHV ORF4 is the most complex alternatively spliced gene encoding a viral complement regulator described to date. KCP inhibits the complement component of the innate immune response, thereby possibly contributing to the in vivo persistence and pathogenesis of this virus.

D J Blackbourn, C Mackewicz, E Barker, J A Levy (1994)Human CD8+ cell non-cytolytic anti-HIV activity mediated by a novel cytokine, In: Research in immunology (Paris)145(8-9)pp. 653-659
DAVID J BLACKBOURN, SUGANTO SUTJIPTO, ROY H DOI, RONALD Y CHUANG (1993)A Simple Method to Distinguish Between Simian Immunodeficiency Virus Isolates by Restriction Analysis of PCR Products, In: DNA and cell biology12(7)pp. 617-622
F-C Ye, DJ Blackbourn, M Mengel, J-P Xie, L-W Qian, W Greene, I-T Yeh, D Graham, S-J Gao (2007)Kaposi's sarcoma-associated herpesvirus promotes angiogenesis by inducing angiopoietin-2 expression via AP-1 and Ets1, In: JOURNAL OF VIROLOGY81(8)pp. 3980-3991 AMER SOC MICROBIOLOGY
Jay A Levy, Frank Hsueh, David J Blackbourn, Diane Wara, Peggy S Weintrub (1998)CD8 Cell Noncytotoxic Antiviral Activity in Human Immunodeficiency Virus-Infected and -Uninfected Children, In: The Journal of infectious diseases177(2)pp. 470-472 The University of Chicago Press

CD8 cells from human immunodeficiency virus (HIV)-infected adults and children can show cytotoxic as well as noncytotoxic activity against viral replication. The noncytotoxic anti-HIV response, measured by suppression of acute viral infection of CD4 cells, has also been observed in uninfected adults who have a history of exposure to HIV. This CD8 cell antiviral activity was found to be detectable as well in ∼50% of uninfected children born of infected mothers. The findings could reflect a protective response of the children to HIV after being exposed to the virus.

David J Blackbourn, Linda F Chuang, Suganto Sutjipto, Keith F Killam, Paula M McCready, Roy H Doi, Yen Li, Ronald Y Chuang (1992)Detection of simian immunodeficiency virus RNA from infected rhesus macaques by the polymerase chain reaction, In: Journal of virological methods37(2)pp. 109-117 Elsevier B.V

A rapid method for the detection of simian immunodeficiency virus (SIV) RNA from peripheral blood mononuclear cells (PBMC) of experimentally infected rhesus macaques by the polymerase chain reaction (PCR) is reported. The PCR was carried out with a complementary DNA (cDNA) template using 3 pairs of primers that were designed to anneal to homologous sequences in conserved regions of 3 molecular clones of SIV mac. The specificity of the primers was confirmed by performing the PCR with template DNA from the 3 molecular clones. SIV-specific RNA was detected from 30 and 50 infected PBMC/6.25 × 10 5 PBMC of two animals.

C E Mackewicz, D J Blackbourn, J A Levy (1995)CD8+ T cells suppress human immunodeficiency virus replication by inhibiting viral transcription, In: Proceedings of the National Academy of Sciences - PNAS92(6)pp. 2308-2312

CD8+ cells from human immunodeficiency virus (HIV)-infected individuals suppress HIV replication in cultured CD4+ cells by a noncytolytic mechanism that involves a secreted CD8(+)-cell antiviral factor (CAF). The results of this study suggest that CD8+ cells, as well as CAF, arrest HIV replication at the level of viral transcription. Culturing naturally infected CD4+ cells actively producing HIV with autologous CD8+ cells or a 50% dilution of culture fluids from these cells results in a > 80% reduction in the number of cells expressing HIV antigens and RNA. This effect was observed within 2 days after exposure to CD8+ cells but required 6 days in the presence of CAF-containing culture fluids to reach the same extent of HIV suppression. Northern blot analysis of CD4+ cell extracts revealed that all viral RNA species (unspliced and single and double spliced) were reduced in quantity to a similar extent. CAF-containing culture fluids also had a direct inhibitory effect on HIV long terminal repeat (LTR)-driven transcription in HIV-infected 1G5 cells carrying an LTR-luciferase construct. Suppression of basal levels of LTR-driven transcription was not detected. Thus, the results suggest that the noncytolytic CD8+ cell antiviral activity observed in HIV infection exerts its effects, at least in part, by specifically interrupting HIV transcription. These findings could help in developing therapies for HIV infection.

Gabrielė Stakaitytė, Nnenna Nwogu, Samuel J. Dobson, Laura M. Knight, Christopher W. Wasson, Francisco Salguero Bodes, David Blackbourn, G. Eric Blair, Jamel Mankouri, Andrew Macdonald, Adrian Whitehouse (2017)Merkel cell polyomavirus small T antigen drives cell motility via Rho-GTPase-induced filopodia formation, In: Journal of Virology92(2)e00940-17pp. 1-21 American Society for Microbiology

Cell motility and migration is a complex, multi-step, and multi-component process, intrinsic to progression and metastasis. Motility is dependent on the activity of integrin receptors and Rho-family GTPases resulting in the remodelling of the actin cytoskeleton and formation of various motile actin-based protrusions. Merkel cell carcinoma (MCC) is an aggressive skin cancer with a high likelihood of recurrence and metastasis. Merkel cell polyomavirus (MCPyV) is associated with the majority of MCC cases, and MCPyV-induced tumourigenesis largely depends on the expression of the small tumour antigen (ST). Since the discovery of MCPyV, a number of mechanisms have been suggested to account for replication and tumourigenesis, but to date, little is known about potential links between MCPyV T antigen expression and the metastatic nature of MCC. Previously, we have described the action of MCPyV ST on the microtubule network and how this impacts on cell motility and migration. Here we demonstrate that MCPyV ST affects the actin cytoskeleton, to promote the formation of filopodia, through a mechanism involving the catalytic subunit of protein phosphatase 4 (PP4C). We also show that MCPyV ST-induced cell motility is dependent upon the activity of Rho-family GTPases Cdc42 and RhoA. In addition, our results indicate that the MCPyV ST-PP4C interaction results in the dephosphorylation of β1 integrin, likely driving the cell motility pathway. These findings describe a novel mechanism by which a tumour virus induces cell motility, which may ultimately lead to cancer metastasis and provides opportunities and strategies for targeted interventions for disseminated MCC.

Z Othman, MK Sulaiman, MM Willcocks, N Ulryck, DJ Blackbourn, B Sargueil, LO Roberts, N Locker (2014)Functional analysis of Kaposi's sarcoma-associated herpesvirus vFLIP expression reveals a new mode of IRES-mediated translation, In: RNA-A PUBLICATION OF THE RNA SOCIETY20(11)pp. 1803-1814 COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT
LM Knight, G Stakaityte, JJ Wood, H Abdul-Sada, DA Griffiths, GJ Howell, R Wheat, GE Blair, NM Steven, A Macdonald, DJ Blackbourn, A Whitehouse (2015)Merkel Cell Polyomavirus Small T Antigen Mediates Microtubule Destabilization To Promote Cell Motility and Migration, In: JOURNAL OF VIROLOGY89(1)pp. 35-47 AMER SOC MICROBIOLOGY
HC Jeffery, RL Wheat, DJ Blackbourn, GB Nash, LM Butler (2013)Infection and transmission dynamics of rKSHV.219 in primary endothelial cells., In: J Virol Methods193(1)pp. 251-259

Kaposi's sarcoma-associated herpesvirus (KSHV) is the aetiologic agent of Kaposi's sarcoma (KS), a tumour of endothelial cell origin. The study of KS development was aided by the generation of a recombinant GFP (latent)/RFP (lytic)-expressing KSHV (rKSHV.219) by Vieira and O'Hearn (2004). In this study the first data characterising primary endothelial cell infection and transmission with this virus is presented. Infection was predominantly latent and the percentage of GFP-positive cells increased over time. Neither horizontal transmission of infection, nor cellular proliferation, explained this increase. Analysis of latency-associated nuclear antigen (LANA-1) expression revealed that a threshold level of infection was required for GFP expression early post infection. At later time points GFP correlated more closely with LANA-1 expression, likely due to the accumulation of GFP over time. This study provides methodological guidance for the use of rKSHV.21. In addition, it highlights potential problems associated with the use of fluorescent proteins as markers of viral infection.

M Okroj, L Mark, A Stokowska, SW Wong, N Rose, DJ Blackbourn, BO Villoutreix, OB Spiller, AM Blom (2009)Characterization of the Complement Inhibitory Function of Rhesus Rhadinovirus Complement Control Protein (RCP), In: JOURNAL OF BIOLOGICAL CHEMISTRY284(1)pp. 505-514 AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Endothelial cells (EC) can present antigen to either CD8(+) T lymphocytes through constitutively expressed major histocompatibility complex class I (MHC-I) or CD4(+) T lymphocytes through gamma interferon (IFN-γ)-induced MHC-II. Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), an EC neoplasm characterized by dysregulated angiogenesis and a substantial inflammatory infiltrate. KSHV is understood to have evolved strategies to inhibit MHC-I expression on EC and MHC-II expression on primary effusion lymphoma cells, but its effects on EC MHC-II expression are unknown. Here, we report that the KSHV infection of human primary EC inhibits IFN-γ-induced expression of the MHC-II molecule HLA-DR at the transcriptional level. The effect is functionally significant, since recognition by an HLA-DR-restricted CD4(+) T-cell clone in response to cognate antigen presented by KSHV-infected EC was attenuated. Inhibition of HLA-DR expression was also achieved by exposing EC to supernatant from KSHV-inoculated EC before IFN-γ treatment, revealing a role for soluble mediators. IFN-γ-induced phosphorylation of STAT-1 and transcription of CIITA were suppressed in KSHV-inoculated EC via a mechanism involving SOCS3 (suppressor of cytokine signaling 3). Thus, KSHV infection resulted in transcriptional upregulation of SOCS3, and treatment with RNA interference against SOCS3 relieved virus-induced inhibition of IFN-γ-induced STAT-1 phosphorylation. Since cell surface MHC-II molecules present peptide antigens to CD4(+) T lymphocytes that can function either as direct cytolytic effectors or to initiate and regulate adaptive immune responses, inhibition of this antigen-presenting pathway would provide a survival advantage to the virus.

LM Butler, HC Jeffery, RL Wheat, PC Rae, K Townsend, KR Alkharsah, TF Schulz, GB Nash, DJ Blackbourn (2011)Kaposi's sarcoma-associated herpesvirus infection of endothelial cells inhibits neutrophil recruitment through an interleukin-6-dependent mechanism: a new paradigm for viral immune evasion., In: J Virol85(14)pp. 7321-7332

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), an endothelial cell (EC) neoplasm characterized by dysregulated angiogenesis and inflammation. KSHV infection of EC causes production of proinflammatory mediators, regarded as possible initiators of the substantial mononuclear leukocyte recruitment seen in KS. Conversely, KSHV immune evasion strategies exist, such as degradation of EC leukocyte adhesion receptors by viral proteins. Here, we report the effects of KSHV infection of primary EC on recruitment of flowing leukocytes. Infection did not initiate adhesion of any leukocyte subset per se. However, on cytokine-stimulated EC, KSHV specifically inhibited neutrophil, but not PBL or monocyte, transmigration, an observation consistent with the inflammatory cell profile found in KS lesions in vivo. This inhibition could be recapitulated on uninfected EC using supernatant from infected cultures. These supernatants contained elevated levels of human interleukin 6 (hIL-6), and both the KSHV- and the supernatant-induced inhibitions of neutrophil transmigration were abrogated in the presence of a hIL-6 neutralizing antibody. Furthermore, preconditioning of EC with hIL-6 mimicked the effect of KSHV. Using RNA interference (RNAi), we show that upregulation of suppressor of cytokine signaling 3 (SOCS3) was necessary for this effect of hIL-6. These studies reveal a novel paracrine mode of KSHV immune evasion, resulting in reduced recruitment of neutrophils, a cell type whose antiviral and antitumor roles are becoming increasingly appreciated. Moreover, the findings have implications for our understanding of the contribution of hIL-6 to the pathogenesis of other inflammatory disorders and tumors in which this cytokine is abundant.

C Areste, DJ Blackbourn (2009)Modulation of the immune system by Kaposi's sarcoma-associated herpesvirus, In: TRENDS IN MICROBIOLOGY17(3)pp. 119-129 ELSEVIER SCIENCE LONDON
Donal McHugh, Nicole Caduff, Mario Henrique M. Barros, Patrick C. Rämer, Ana Raykova, Anita Murer, Vanessa Landtwing, Isaak Quast, Christine T. Styles, Michael Spohn, Adeola Fowotade, Henri-Jacques Delecluse, Alexandra Papoudou-Bai, Yong-Moon Lee, Jin-Man Kim, Jaap Middeldorp, Thomas F. Schulz, Ethel Cesarman, Andrea Zbinden, Riccarda Capaul, Robert E. White, Martin J. Allday, Gerald Niedobitek, David Blackbourn, Adam Grundhoff, Christian Münz (2017)Persistent KSHV Infection Increases EBV-Associated Tumor Formation In Vivo via Enhanced EBV Lytic Gene Expression, In: Cell Host & Microbe22(1)pp. 61-73.e7 Elsevier

The human tumor viruses Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) establish persistent infections in B cells. KSHV is linked to primary effusion lymphoma (PEL), and 90% of PELs also contain EBV. Studies on persistent KSHV infection in vivo and the role of EBV co-infection in PEL development have been hampered by the absence of small animal models. We developed mice reconstituted with human immune system components as a model for KSHV infection and find that EBV/KSHV dual infection enhanced KSHV persistence and tumorigenesis. Dual-infected cells displayed a plasma cell-like gene expression pattern similar to PELs. KSHV persisted in EBV-transformed B cells and was associated with lytic EBV gene expression, resulting in increased tumor formation. Evidence of elevated lytic EBV replication was also found in EBV/KSHV dually infected lymphoproliferative disorders in humans. Our data suggest that KSHV augments EBV-associated tumorigenesis via stimulation of lytic EBV replication.

OB Spiller, L Mark, CE Blue, DG Proctor, JA Aitken, AM Blom, DJ Blackbourn (2006)Dissecting the regions of virion-associated Kaposi's sarcoma-associated herpesvirus complement control protein required for complement regulation and cell binding, In: JOURNAL OF VIROLOGY80(8)pp. 4068-4078 AMER SOC MICROBIOLOGY

Members of the herpesvirus family have evolved the ability to persist in their hosts by establishing a reservoir of latently infected cells each carrying the viral genome with reduced levels of viral protein synthesis. In order to spread within and between hosts, in some cells, the quiescent virus will reactivate and enter lytic cycle replication to generate and release new infectious virus particles. To allow the efficient generation of progeny viruses, all herpesviruses have evolved a wide variety of immunomodulatory mechanisms to limit the exposure of cells undergoing lytic cycle replication to the immune system. Here we have focused on the human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) that, uniquely among the eight human herpesviruses identified to date, have growth transforming potential. Most people infected with these viruses will not develop cancer, viral growth-transforming activity being kept under control by the host's antigen-specific immune responses. Nonetheless, EBV and KSHV are associated with several malignancies in which various viral proteins, either predominantly or exclusively latency-associated, are expressed; at least some of these proteins also have immunomodulatory activities. Of these malignancies, some are the result of a disrupted virus/immune balance through genetic, infectious or iatrogenic immune suppression. Others develop in people that are not overtly immune suppressed and likely modulate the immunological response. This latter aspect of immune modulation by EBV and KSHV forms the basis of this review.

SAR Rezaee, C Cunningham, AJ Davison, DJ Blackbourn (2006)Kaposi's sarcoma-associated herpesvirus immune modulation: an overview, In: JOURNAL OF GENERAL VIROLOGY87pp. 1781-1804 SOC GENERAL MICROBIOLOGY
Andrea L. Darling, David J. Blackbourn, Kourosh R. Ahmadi, Susan A. Lanham-New (2018)Vitamin D supplement use and associated demographic, dietary and lifestyle factors in South Asians (n 8024) aged 40-69 years: analysis of the UK Biobank Cohort, In: Public Health Nutrition21(14)pp. 2678-2688 Cambridge University Press

Objective: Vitamin D deficiency (serum 25-hydroxyvitamin D˂25nmol/L) is extremely common in western-dwelling South Asians but evidence regarding vitamin D supplement usage in this group is very limited. This work identifies demographic, dietary and lifestyle predictors associated with vitamin D supplement use. Design: Cross-sectional analysis of baseline vitamin D supplement use data. Setting: UK Biobank cohort. Subjects: In total, n 8024 South Asians (Bangladeshi, Indian, Pakistani), aged 40-69 years. Results: Twenty-three % of men and 39% of women (P˂0.001) [22% of Bangladeshis, 32% of Indians, 25% of Pakistanis (P˂0.001)] took a vitamin D containing supplement. Median vitamin D intakes from diet were low at 1.0-3.0 micrograms per day, being highest in Bangladeshis and lowest in Indians (P˂0.001). Logistic regression modelling showed that females had a higher odds of vitamin D supplement use than males (odds ratio (OR) = 2.02; 95% confidence interval (CI) 1.79 to 2.28). A lower supplement usage was seen in younger persons (40-60 years) (OR=0.75; 95% CI 0.65 to 0.86 reference= ˃60 years), and those living outside of Greater London (OR=0.53 to 0.77), with borderline trends for a lower body mass index, higher oily fish intake and higher household income associated with increased odds of vitamin D supplement use. Conclusions: Vitamin D supplements were not used by most South Asians and intakes from diet alone are likely to be insufficient to maintain adequate vitamin D status. Public health strategies are now urgently required to promote the use of vitamin D supplements in these specific UK South Asian sub-groups.

Evelyne T Lennette, David J Blackbourn, Jay A Levy (1996)Antibodies to human herpesvirus type 8 in the general population and in Kaposi's sarcoma patients, In: The Lancet (British edition)348(9031)pp. 858-861 Elsevier Ltd

Much of the evidence that human herpesvirus type 8 (HHV-8) is associated with Kaposi's sarcoma (KS) has come from molecular studies of HHV-8 DNA. Seroepidemiological studies have been hampered by the lack of a reliable assay. The serological data reported here were obtained by means of a mouse monoclonal antibody-enhanced immunofluorescence assay for antibodies to lytic and latent HHV-8 antigens. 1435 single samples of serum (or plasma) from many different disease groups and parts of the world were assayed. All patients with African endemic KS and 96% of American patients with AIDS-associated KS were seropositive for lytic antigen, as were 90% of American HIV-infected homosexual men; by contrast only 23% of HIV-seropositive drug users and 21% of HIV-seropositive women were positive for HHV-8 antibody. Factor VIII treatment before 1983 did not increase the risk of HHV-8 infection in patients with haemophilia. In the American general population, about 25% of adults (including volunteer blood donors) and 2–8% of children had antibodies to HHV-8. Our data are consistent with HHV-8 being primarily associated with sexual transmission, but the HHV-8 seropositivity rate in American children suggests that there is a non-sexual route of HHV-8 infection also. On the evidence available so far, the risk of parenteral transmission is low.

David J Blackbourn, Sue Fujimura, Tim Kutzkey, Jay A Levy (2000)Induction of human herpesvirus-8 gene expression by recombinant interferon gamma, In: AIDS (London)14(1)pp. 98-99
R Wheat, C Roberts, T Waterboer, J Steele, J Marsden, NM Steven, DJ Blackbourn (2014)Inflammatory cell distribution in primary merkel cell carcinoma., In: Cancers (Basel)6(2)pp. 1047-1064

Merkel cell carcinoma (MCC) is an aggressive poorly differentiated neuroendocrine cutaneous carcinoma associated with older age, immunodeficiency and Merkel cell polyomavirus (MCPyV) integrated within malignant cells. The presence of intra-tumoural CD8+ lymphocytes reportedly predicts better MCC-specific survival. In this study, the distribution of inflammatory cells and properties of CD8+ T lymphocytes within 20 primary MCC specimens were characterised using immunohistochemistry and multicolour immunofluorescent staining coupled to confocal microscopy. CD8+ cells and CD68+ macrophages were identified in 19/20 primary MCC. CD20+ B cells were present in 5/10, CD4+ cells in 10/10 and FoxP3+ cells in 7/10 specimens. Only two specimens had almost no inflammatory cells. Within specimens, inflammatory cells followed the same patchy distribution, focused at the edge of sheets and nodules and, in some cases, more intense in trabecular areas. CD8+ cells were outside vessels on the edge of tumour. Those few within malignant sheets typically lined up in fine septa not contacting MCC cells expressing MCPyV large T antigen. The homeostatic chemokine CXCL12 was expressed outside malignant nodules whereas its receptor CXCR4 was identified within tumour but not on CD8+ cells. CD8+ cells lacked CXCR3 and granzyme B expression irrespective of location within stroma versus malignant nodules or of the intensity of the intra-tumoural infiltrate. In summary, diverse inflammatory cells were organised around the margin of malignant deposits suggesting response to aberrant signaling, but were unable to penetrate the tumour microenvironment itself to enable an immune response against malignant cells or their polyomavirus.

CS McKimmie, MD Singh, K Hewit, O Lopez-Franco, M Le Brocq, S Rose-John, KM Lee, AH Baker, R Wheat, DJ Blackbourn, RJB Nibbs, GJ Graham (2013)An analysis of the function and expression of D6 on lymphatic endothelial cells, In: BLOOD121(18)pp. 3768-3777 AMER SOC HEMATOLOGY
BR Jackson, JR Boyne, M Noerenberg, A Taylor, GM Hautbergue, MJ Walsh, R Wheat, DJ Blackbourn, SA Wilson, A Whitehouse (2011)An Interaction between KSHV ORF57 and UIF Provides mRNA-Adaptor Redundancy in Herpesvirus Intronless mRNA Export, In: PLOS PATHOGENS7(7)ARTN e1002 PUBLIC LIBRARY SCIENCE
L Mark, OB Spiller, DJ Blackbourn, AM Blom (2007)Molecular details of the complement regulatory and cell attaching functions of KCP, In: MOLECULAR IMMUNOLOGY44(1-3)pp. 213-213
L Wang, M Pietrek, MM Brinkmann, A Haevemeier, I Fischer, B Hillenbrand, O Dittrich-Breiholz, M Kracht, S Chanas, DJ Blackbourn, TF Schulz (2009)Identification and functional characterization of a spliced rhesus rhadinovirus gene with homology to the K15 gene of Kaposi's sarcoma-associated herpesvirus, In: JOURNAL OF GENERAL VIROLOGY90pp. 1190-1201 SOC GENERAL MICROBIOLOGY
C Aresté, DJ Blackbourn (2006)HIV Tat-mediated transcriptional regulation of proteasome protein cleavage specificity., In: Biochem J396(2)pp. e13-e15

The major antigen-adapted immune response protecting a vertebrate against virus infection is that mediated by CTLs (cytotoxic T-lymphocytes). CTLs destroy virus-infected cells, thereby containing the infection. They are activated by recognition of peptide antigens or epitopes, presented to them in the context of MHC I proteins. These epitopes are derived from proteolytic degradation of endogenously synthesized proteins, which is mediated by the proteasome. Augmentation of epitope presentation by MHC I is thought to be effected by the immunoproteasome, induced in response to IFN-gamma (interferon-gamma) in some cells, and constitutively expressed in others. In this issue of the Biochemical Journal, Remoli and colleagues describe the manipulation of the immunoproteasome by the Tat (transcriptional activation) protein of HIV. The authors show that Tat deregulates the balance of the three proteins, LMP2 (low-molecular-mass polypeptide 2), LMP7 and MECL1 (multicatalytic endopeptidase complex-like 1), which distinguish the immunoproteasome from the proteasome, and they provide a molecular explanation. Intracellular Tat sequesters IRF-1 (interferon-regulatory factor-1) from its cognate promoter element, where normally it associates with STAT1 (signal transducer and activator of transcription 1) to activate basal transcription of the LMP2 gene. LMP2 expression is inhibited as a consequence, skewing the stoichiometry of the immunoproteasome and changing its enzymatic activity. These findings provide a molecular account of an immunomodulatory activity of HIV: changing the peptide antigen profile of cells expressing or exposed to Tat. They may also provide an avenue for manipulating vaccine efficacy and specificity with Tat-based adjuvants.

M Okroj, L Mark, A Stokowska, S Wong, N Rose, D Blackbourn, B Villoutreix, B Spiller, A Blom (2008)Characterization of the complement inhibitory function of Rhesus rhadinovirus, In: MOLECULAR IMMUNOLOGY45(16)pp. 4172-4173
R Colman, DJ Blackbourn (2008)Risk factors in the development of Kaposi's sarcoma., In: AIDS22(13)pp. 1629-1632
David J Blackbourn, Evelyne T Lennette, John Ambroziak, Dan V Mourich, Jay A Levy (1998)Human Herpesvirus 8 Detection in Nasal Secretions and Saliva, In: The Journal of infectious diseases177(1)pp. 213-216 The University of Chicago Press

The presence of human herpesvirus 8 (HHV-8) was determined by polymerase chain reaction (PCR) in nasal secretions and saliva from 14 HHV-8-seropositive persons, including 8 Kaposi's sarcoma patients: 7 were human immunodeficiency virus type 1-infected, 6 of whom were asymptomatic. HHV-8 was detected in one or both body fluids in 8 (57%) of 14 subjects. Parallel PCR testing revealed the concomitant presence of cytomegalovirus, Epstein-Barr virus, and HHV-6 in various combinations in these body fluids. These data indicate frequent shedding of multiple herpesviruses in nasal secretions and saliva, particularly in Kaposi's sarcoma patients. Both body fluids are therefore potential sources HHV-8 by nonsexual transmission.

Frank W Hsueh, Christopher M Walker, David J Blackbourn, Jay A Levy (1994)Suppression of HIV Replication by CD8+ Cell Clones Derived from HIV-Infected and Uninfected Individuals, In: Cellular immunology159(2)pp. 271-279 Elsevier Inc

CD8+ cell clones have been derived from peripheral blood mononuclear cells of human immunodeficiency virus (HIV)-infected and uninfected individuals. Several of these cloned cells have the ability to suppress HIV replication when cocultured with CD4+ cells acutely infected in the laboratory with HIV or with infected CD4+ cells from infected subjects. Suppression of virus production occurs without killing the target cells. With the CD8+ cell clones studied, this antiviral response correlated with production of a filterable factor that has antiviral activity. These cell clones offer the opportunity for identification of the factor mediating suppression of HIV replication. Moreover, adoptive transfer of cell clones might provide a valuable therapeutic approach for HIV-infected individuals.

David J Blackbourn, Dennis Osmond, Jay A Levy, Evelyne T Lennette (1999)Increased Human Herpesvirus 8 Seroprevalence in Young Homosexual Men Who Have Multiple Sex Contacts with Different Partners, In: The Journal of infectious diseases179(1)pp. 237-239 University Chicago Press

The objective of this study was to evaluate the behavioral risks that are associated with human herpesvirus 8 (HHV-8) infection in a cohort of young homosexual men. Seventy-nine subjects (ages 22–33 years) who completed a questionnaire about their sexual and drug use behavior over the preceding year were recruited from the San Francisco Young Men's Health Study. Plasma samples were tested for anti-HHV-8 antibodies using an indirect IFA. Thirty-eight subjects (48.1%) were infected with HHV-8. HHV-8 infection was significantly linked to an increasing number of male sex partners (P = .025, Mantel-Haenszel χ2 test for trend), suggesting a strong association between HHV-8 infection and multiple homosexual contacts.

J Wuu, L F Chuang, D J Blackbourn, K F Killam, M Israel, R Y Chuang (1992)Evaluation of anti-SIV potential of anti-neoplastic anthracyclines, In: Proceedings of the Western Pharmacology Society35pp. 141-146
Rolf Renne, David Blackbourn, Denise Whitby, Jay Levy, Don Ganem (1998)Limited Transmission of Kaposi’s Sarcoma-Associated Herpesvirus in Cultured Cells, In: Journal of virology72(6)pp. 5182-5188 American Society for Microbiology

Kaposi’s sarcoma-associated herpesvirus (KSHV) (also called human herpesvirus 8) is a novel gammaherpesvirus strongly implicated in the pathogenesis of Kaposi’s sarcoma. Although virions can be produced in high yield from latently infected B-cell lines treated with phorbol esters, little is known about the infectivity of such virus, and efficient serial propagation of KSHV has been problematic. Here we report on the infectivity of KSHV produced from phorbol-induced BCBL-1 cells, employing an assay based on the detection of a spliced late mRNA by a sensitive reverse transcriptase PCR (RT-PCR) method. The results of this study confirm previous observations that 293 cells are susceptible to viral infection; however, infection with BCBL-1-derived virus is inefficient and the pattern of viral gene expression in infected cells may not fully reproduce that of authentic lytic infection. In keeping with this finding, serial propagation of BCBL-1-derived virus could not be demonstrated on 293 cells. Eleven of 38 other cell lines tested also supported KSHV infection, as judged by this RT-PCR assay, including cells of B-cell, endothelial, epithelial, and fibroblastic origin; however, in all cases, infection proceeded at or below the levels observed in 293 cells.

Charles Cunningham, Suzanne Barnard, David J Blackbourn, Andrew J Davison (2003)Transcription mapping of human herpesvirus 8 genes encoding viral interferon regulatory factors, In: Journal of general virology84(Pt 6)pp. 1471-1483

The human herpesvirus 8 (HHV-8) genome contains four tandemly arranged genes encoding viral interferon regulatory factors (vIRF-1 to 4) located between genes 57 and 58. Transcript mapping techniques were employed to determine the sizes, ends and splicing patterns of mRNAs specified by these genes in HHV-8-infected cell lines untreated or chemically induced into the lytic growth cycle. Depending on the cell line used, vIRF-3 transcription was minimally or not induced (i.e. expressed with latent kinetics), whereas the other vIRFs were inducible (i.e. expressed with lytic kinetics). Each gene possessed its own promoter (or promoters) and polyadenylation sites, and all but vIRF-1 were spliced from two exons. vIRF-1 was transcribed in uninduced and induced cells from a single initiation site preceded by a TATA box, with the possible use of an additional TATA box and initiation site in uninduced cells. In induced cells, vIRF-2 was transcribed from a single major initiation site preceded by a TATA box, and vIRF-4 was expressed from two sites each preceded by a TATA box. Transcripts for these genes were insufficiently abundant in uninduced cells to map the 5'-ends. vIRF-3 lacks an obvious TATA box and exhibited heterogeneous 5'-ends in uninduced and induced cells. These data clarify and extend our understanding of the structure and transcription of the HHV-8 vIRF genes.

Clare E Blue, O Brad Spiller, David J Blackbourn (2004)The relevance of complement to virus biology, In: Virology (New York, N.Y.)319(2)pp. 176-184
Steven Milligan, Mairi Robinson, Elizabeth O'Donnell, David J Blackbourn (2004)Inflammatory cytokines inhibit Kaposi's sarcoma-associated herpesvirus lytic gene transcription in in vitro-infected endothelial cells, In: Journal of virology78(5)pp. 2591-2596

The response of Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) to inflammatory cytokine treatment of experimentally infected endothelial cells was investigated. The cytokines inhibited spontaneous KSHV lytic gene expression but not the level of infection. The data suggest that if inflammatory cytokines present in KS lesions contribute to KSHV pathogenesis, they do so in part by promoting latent KSHV infection of the endothelial cells.

YUAN LIU, D. J BLACKBOURN, L. F CHUANG, K. F KILLAM, R. Y CHUANG (1992)Effects of in vivo and in vitro administration of morphine sulfate upon rhesus macaque polymorphonuclear cell phagocytosis and chemotaxis, In: The Journal of pharmacology and experimental therapeutics263(2)pp. 533-539 American Society for Pharmacology and Experimental Therapeutics
C P Locher, D J Blackbourn, B A Castro, K M Brasky, J A Levy (1996)Susceptibility of peripheral blood mononuclear cells from gorillas, orangutans and baboons to diverse HIV isolates, In: AIDS (London)10(12)pp. 1438-1440
David J Blackbourn, Jay A Levy (1997)Human herpesvirus 8 in semen and prostate, In: AIDS (London)11(2)pp. 249-250
David J Blackbourn, John Ambroziak, Evelyne Lennette, Melanie Adams, Bineetha Ramachandran, Jay A Levy (1997)Infectious human herpesvirus 8 in a healthy North American blood donor, In: The Lancet (British edition)349(9052)pp. 609-611 Elsevier Ltd

Molecular studies have provided strong evidence for the association of human herpesvirus 8 (HHV-8) with Kaposi's sarcoma. These data have been supported by serological studies, which have also suggested that HHV-8 can be found in the healthy population. We report the presence of infectious HHV-8 in a healthy donor to a North American blood bank. We examined the peripheral blood mononuclear cells or CD19 cells of blood donors by PCR for evidence of HHV-8 infection. The CD19 cells were separated from peripheral blood mononuclear cells by immunomagneticbead selection. To enhance detection of HHV-8, the CD19 cells from eleven unsystematically selected blood donors were activated with phorbol ester and recombinant interleukin-6; the culture fluid was filtered and inoculated onto HHV-8-negative target CD19 cells that had been prepared from phytohaemagglutinin-stimulated peripheral blood mononuclear cells. These inoculated target cells were cultured for 3 days and then analysed for HHV-8 sequences by PCR. Serum samples were tested for antibodies to HHV-8 by an indirect immunofluorescence assay. One blood donor was consistently found to be infected with HHV-8 by PCR after the cell-culture activation procedure. He was seropositive for the virus. The HHV-8 recovered was infectious, as shown by a reverse-transcription-PCR technique that detected HHV-8 RNA in the inoculated target cells. These data provide the first indication that HHV-8 can be recovered from the blood of a healthy individual, a blood donor, and that the virus is infectious. This observation suggests that HHV-8 could be transmitted by blood transfusion, a possibility that merits further study.

David J Blackbourn, Christopher P Locher, Bineetha Ramachandran, Susan W Barnett, Krishna K Murthy, Kenneth D Carey, Kathleen M Brasky, Jay A Levy (1997)CD8+ cells from HIV-2-infected baboons control HIV replication, In: AIDS (London)11(6)pp. 737-746
C. P LOCHER, D. J BLACKBOURN, B. G HERNDIER, G REYES-TERAN, S. W BARNETT, K. K MURTHY, J. A LEVY (1998)Transient virus infection and pathogenesis of a new HIV type 2 isolate, UC12, in baboons, In: AIDS research and human retroviruses14(1)pp. 79-82 Liebert
Linda Mark, Wen H Lee, O Brad Spiller, David Proctor, David J Blackbourn, Bruno O Villoutreix, Anna M Blom (2004)The Kaposi's sarcoma-associated herpesvirus complement control protein mimics human molecular mechanisms for inhibition of the complement system, In: The Journal of biological chemistry279(43)pp. 45093-45101

Kaposi's sarcoma-associated human herpesvirus (KSHV) is thought to cause Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. Previously, we reported that the KSHV complement control protein (KCP) encoded within the viral genome is a potent regulator of the complement system; it acts both as a cofactor for factor I and accelerates decay of the C3 convertases (Spiller, O. B., Blackbourn, D. J., Mark, L., Proctor, D. G., and Blom, A. M. (2003) J. Biol. Chem. 278, 9283-9289). KCP is a homologue to human complement regulators, being comprised of four complement control protein (CCP) domains. In this, the first study to identify the functional sites of a viral homologue at the amino acid level, we created a three-dimensional homology-based model followed by site-directed mutagenesis to locate complement regulatory sites. Classical pathway regulation, both through decay acceleration and factor I cleavage of C4b, required a cluster of positively charged amino acids in CCP1 stretching into CCP2 (Arg-20, Arg-33, Arg-35, Lys-64, Lys-65, and Lys-88) as well as positively (Lys-131, Lys-133, and His-135) and negatively (Glu-99, Glu-152, and Asp-155) charged areas at opposing faces of the border region between CCPs 2 and 3. The regulation of the alternative pathway (via factor I-mediated C3b cleavage) was found to both overlap with classical pathway regulatory sites (Lys-64, Lys-65, Lys-88 and Lys-131, Lys-133, His-135) as well as require unique, more C-terminal residues in CCPs 3 and 4 (His-158, His-171, and His-213) and CCP 4 (Phe-195, Phe-207, and Leu-209). We show here that KCP has evolved to maintain the spatial structure of its functional sites, especially the positively charged patches, compared with host complement regulators.

J. A AMBROZIAK, D. J BLACKBOURN, B. G HERNDIER, R. G GLOGAU, J. H GULLETT, A. R MCDONALD, E. T LENNETTE, J. A LEVY (1995)Herpes-like sequences in HIV-infected and uninfected Kaposi's sarcoma patients, In: Science (American Association for the Advancement of Science)268(5210)pp. 582-583 American Association for the Advancement of Science
O Brad Spiller, David J Blackbourn, Linda Mark, David G Proctor, Anna M Blom (2003)Functional activity of the complement regulator encoded by Kaposi's sarcoma-associated herpesvirus, In: The Journal of biological chemistry278(11)pp. 9283-9289

Kaposi's sarcoma-associated herpesvirus (KSHV) is closely associated with Kaposi's sarcoma and certain B-cell lymphomas. The fourth open reading frame of the KSHV genome encodes a protein (KSHV complement control protein (KCP, previously termed ORF4)) predicted to have complement-regulating activity. Here, we show that soluble KCP strongly enhanced the decay of classical C3-convertase but not the alternative pathway C3-convertase, when compared with the host complement regulators: factor H, C4b-binding protein, and decay-accelerating factor. The equilibrium affinity constant (KD) of KCP for C3b and C4b was determined by surface plasmon resonance analysis to range between 0.47-10 microM and 0.025-6.1 microM, respectively, depending on NaCl concentration and cation presence. Soluble and cell-associated KCP acted as a cofactor for factor I (FI)-mediated cleavage of both C4b and C3b and induced the cleavage products C4d and iC3b, respectively. In the presence of KCP, FI further cleaved iC3b to C3d, which has never been described before as complement receptor 1 only mediates the production of C3dg by FI. KCP would enhance virus pathogenesis through evading complement attack, opsonization, and anaphylaxis but may also aid in targeting KSHV to one of its host reservoirs since C3d is a ligand for complement receptor 2 on B-cells.

Ioanna A DIALYNA, David GRAHAM, Rahim REZAEE, Clare E BLUE, Nikolaos G STAVRIANEAS, Hubert G. M NEISTERS, Demetrios A SPANDIDOS, David J BLACKBOURN (2004)Anti-HHV-8/KSHV antibodies in infected individuals inhibit infection in vitro, In: AIDS (London)18(9)pp. 1263-1270 Lippincott Williams & Wilkins
David J Blackbourn, Carl E Mackewicz, Edward Barker, Thomas K Hunt, Brian Herndier, Ashley T Haase, Jay A Levy (1996)Suppression of HIV replication by lymphoid tissue CD8+ cells correlates with the clinical state of HIV-infected individuals, In: Proceedings of the National Academy of Sciences - PNAS93(23)pp. 13125-13130 The National Academy of Sciences of the USA

Lymphoid tissues from asymptomatic HIV-infected individuals, as compared with symptomatic HIV-infected subjects, show limited histopathological changes and lower levels of HIV expression. In this report we correlate the control of HIV replication in lymph nodes to the non-cytolytic anti-HIV activity of lymphoid tissue CD8 + cells. Five subjects at different stages of HIV-related disease were studied and the ability of their CD8 + cells, isolated from both lymphoid tissue and peripheral blood, to inhibit HIV replication was compared. CD8 + cells from lymphoid tissue and peripheral blood of two HIV-infected long-term survivors suppressed HIV replication at a low CD8 + :CD4 + cell ratio of 0.1. The CD8 + cells from the lymphoid tissue of a third asymptomatic subject suppressed HIV replication at a CD8 + :CD4 + cell ratio of 0.25; the subject’s peripheral blood CD8 + cells showed this antiviral response at a lower ratio of 0.05. The lymphoid tissue CD8 + cells from two AIDS patients were not able to suppress HIV replication, and the peripheral blood CD8 + cells of only one of them suppressed HIV replication. The plasma viremia, cellular HIV load as well as the extent of pathology and virus expression in the lymphoid tissue of the two long-term survivors, were reduced compared with these parameters in the three other subjects. The data suggest that the extent of anti-HIV activity by CD8 + cells from lymphoid tissue relative to peripheral blood correlates best with the clinical state measured by lymphoid tissue pathology and HIV burden in lymphoid tissues and blood. The results add further emphasis to the importance of this cellular immune response in controlling HIV pathogenesis.

O. Brad Spiller, Mairi Robinson, Elizabeth O'Donnell, Steven Milligan, B. Paul Morgan, Andrew J Davison, David J Blackbourn (2003)Complement Regulation by Kaposi's Sarcoma-Associated Herpesvirus ORF4 Protein, In: Journal of virology77(1)pp. 592-599 American Society for Microbiology

Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with three types of human tumor: Kaposi's sarcoma, multicentric Castleman's disease, and primary effusion lymphoma. The virus encodes a number of proteins that participate in disrupting the immune response, one of which was predicted by sequence analysis to be encoded by open reading frame 4 (ORF4). The predicted ORF4 protein shares homology with cellular proteins referred to as regulators of complement activation. In the present study, the transcription profile of the ORF4 gene was characterized, revealing that it encodes at least three transcripts, by alternative splicing mechanisms, and three protein isoforms. Functional studies revealed that each ORF4 protein isoform inhibits complement and retains a C-terminal transmembrane domain. Consistent with the complement-regulating activity, we propose to name the proteins encoded by the ORF4 gene collectively as KSHV complement control protein (KCP). KSHV ORF4 is the most complex alternatively spliced gene encoding a viral complement regulator described to date. KCP inhibits the complement component of the innate immune response, thereby possibly contributing to the in vivo persistence and pathogenesis of this virus.

S.W Barnett, H.S Legg, Y Sun, J Klinger, D.J Blackbourn, C.P Locher, J.A Levy (1996)Molecular Cloning of the Human Immunodeficiency Virus Subtype 2 Strain HIV-2UC2, In: Virology (New York, N.Y.)222(1)pp. 257-261 Elsevier Inc

An infectious molecular clone was derived from the HIV-2UC2isolate that previously was found to persistently infect and induce an AIDS-like disease syndrome in baboons. The molecularly cloned virus (HIV-2UC2mc) showedin vitroproperties similar to those of the parental isolate with regard to T-cell tropism, cytopathicity, and the ability to infect primary baboon PBMC. Nevertheless, when inoculated into two baboons, the cloned virus showed a limited ability to replicate in these animals. DNA sequence analysis revealed a defectivevprgene in the UC2mc as well as in the pathogenic parental UC2 strain. Thus, thevprgene is not required for the induction of disease in baboons. The attenuated infectious molecular clone of UC2 should be useful for future studies designed to map the genetic determinants of HIV-2 pathogenesis in the baboon model and to evaluate vaccine strategies.

Christopher P Locher, David J Blackbourn, Jay A Levy (1999)Suppression of human immunodeficiency virus type 1 replication by a soluble factor produced by CD8+ lymphocytes from HIV-2-infected baboons, In: Immunology letters66(1)pp. 151-157 Elsevier B.V

Human immunodeficiency virus type 2 (HIV-2)-infected baboons (Papio cynocephalus) provide a valuable animal model for the study of acquired immunodefidency syndrome (AIDS) pathogenesis since many features of disease progression resemble HIV-1-infection of humans. In some HIV-2-infected baboons that are clinically healthy, a CD8+ cell antiviral response, that is partly mediated by a soluble factor, controls viral replication in vitro. In the present study, we demonstrate that CD8+ cells derived from HIV-2-infected baboon peripheral blood, lymph nodes, adenoids and tonsils had antiviral activity in co-cultures of CD8+ and CD4+ cells that inversely correlates with viral load. A soluble factor was found to be active against the chemokine-resistant, syncytium-inducing HIV-1 SF2 and HIV-1 SF33 isolates and was relatively heat stable at 100°C for 10 min. Moreover, inhibition of the transcription from the long terminal repeat of HIV-1 was observed in 1G5 cells after activation with phorbol 12-myristate 13-acetate. Therefore, the soluble suppressing activity of CD8+ cells in HIV-2-infected baboons may be analogous to the CD8+ cell antiviral factor described in human HIV-infected asymptomatic people.

David J Blackbourn, Evelyne Lennette, Barbara Klencke, Ashlee Moses, Bala Chandran, Mark Weinstein, Richard G Glogau, Marlys H Witte, Dennis L Way, Tim Kutzkey, Brian Herndier, Jay A Levy (2000)The restricted cellular host range of human herpesvirus 8, In: AIDS (London)14(9)pp. 1123-1133