Professor David J. Blackbourn


Head of the School of Biosciences and Medicine
15 AX 01
Personal assistant: Elise Frost-Bridges
+44 (0)1483 686920

Biography

Previous roles

2013
Head of Department of Microbial and Cellular Sciences
University of Surrey
2013
Honorary Senior Research Fellow
School of Cancer Sciences, University of Birmingham
2010
Professor of Virology
University of Birmingham
2005
Reader in Tumour Virology
University of Birmingham
2005
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

Research interests

Research collaborations

My publications

Highlights

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.

Publications

Inflammation is a defence mechanism that higher organisms have evolved, in order to be protected from pathogenic infections and injury, and also to promote the healing process. Key players of the inflammatory responses are signalling pathways, which are tightly controlled to allow fast activation and efficient termination. Dysregulation of the fine-tune mechanisms that regulate these responses results in a failure to clear infection or, on the contrary, in the establishment of excessive, chronic inflammation. Ubiquitylation has emerged as a pivotal process in the regulation of innate immunity, by controlling both, the activation and termination of inflammatory responses. This thesis has examined mechanisms of inhibition of innate immune signalling by the ubiquitin system. A commercially available RNAi screen for Cullin-RING (CLR) complexes, revealed four novel inhibitors of the NF-κB pathway, SPSB1, FBXO8, FBXO42 and FBXL21, although due to time constrains only the characterisation of the first two proteins has taken place. Data presented in this thesis has revealed that SPSB1, a SOCS-box-containing substrate receptor protein, member of the Cullin-5 complex, controls only the NF-κB pathway, but not the IRF-3, AP-1 or JAK/STAT pathways, whereas its inhibitory activity on NF-κB lies at the level or downstream of the p50/p65 heterodimer, by a yet unknown mechanism. Furthermore, the ability of SPSB1 to inhibit the inflammatory responses driven by NF-κB was examined in the context of respiratory syncytial virus (RSV) infection. On the other hand, FBXO8, an F-box-containing substrate receptor protein, member of the Cullin-1 complex, has been shown here to negatively regulate NF-κB by acting at the level or upstream of the IKK complex, while its activity extents also on the AP-1 signalling cascade. In addition, a proteomic approach has revealed Cullin-4 as a binding partner of FBXO8, which has been successfully confirmed by conventional immunoprecipitations (IPs). The exact mechanism by which FBXO8 acts as an inhibitor of NF-κB and AP-1 signalling pathways has not been revealed and remains as focus of future studies. Opposingly to that discussed above, pathogens have evolved to escape, or antagonise the regulatory mechanisms mentioned above to their advantage. Poxviruses are known to express numerous proteins that counteract the host defence, and vaccinia virus (VACV) has been the main focus of research, due to its use as a vaccine vector. Poxviruses are the only DNA viruses known to replicate exclusively in the cytosol, which makes them susceptible to cytosolic DNA sensing, a pivotal cellular mechanism for pathogen recognition upon infection. Among the identified DNA sensors, cGAS is one of the most essential, which activates STING via the cGAMP production. Activation of STING results in its phosphorylation, dimerisation and translocation to the Golgi, where it mediates the IRF-3 activation. Data presented in this thesis revealed that infection with the attenuated VACV strain MVA, activated IRF-3 via the cGAS-STING axis and accordingly, STING dimerised and was phosphorylated. Conversely, STING dimerisation and phosphorylation was inhibited during infections with VACV strains Copenhagen (COP) and Western Reserve (WR) and in response to transfected DNA and cGAMP, thus demonstrating the efficient suppression of DNA sensing and IRF-3 activation by these strains. Infection with vv811 strain, a VACV deletion mutant lacking all the identified IRF-3 inhibitors, together with the inhibitors of DNA-PK DNA sensor, retained the ability of blocking STING activation, indicating that STING inhibition is independent of their activity. A similar inhibition of DNA-induced STING activation was also observed during cowpox and mousepox viral infections, suggesting that this mechanism might be conserved among the species. This thesis has generated a unique knowledge about the poxvirus-host interactions, as this is the first proof of poxviruses targeting DNA sensing directly at the level of cGAS-STING axis.
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 <25 nmol/L (severe deficiency) and 92% (n 5918) had 25(OH)D <50 nmol/L (insufficiency). Twenty per cent (n 1287) had 25(OH)D concentration <15 nmol/L (very severe deficiency). When n 824 participants with undetectable (<10 nmol/L) 25(OH)D measurements were included (total n 7257), 29% (n 2105) had 25(OH)D <15 nmol/L, 60% (n 4354) had 25(OH)D <25 nmol/L and 93% (n 6749) had 25(OH)D < 50 nmol/L. Logistic regression predictors of 25(OH)D <25 nmol/L included the following characteristics: being male; Pakistani; higher body mass index; 40-59 years old; never consuming oily fish; summer sun exposure < 5 hours per day, not using a vitamin D containing supplement, measurement in winter or spring and vegetarianism. In terms of region, median 25(OH)D concentration was 19-20 nmol/L in Scotland, Northern England, the Midlands and Wales. Across Southern England and London it was slightly higher at 24-25 nmol/L. Our analyses suggest the need for increased awareness of vitamin D deficiency in South Asians as well as urgent public health interventions to prevent and treat vitamin D deficiency in this group.
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.
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
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
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.
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.
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.
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.
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.
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
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
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
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
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.
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
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.
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
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
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.
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
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.
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.

R Colman, DJ Blackbourn (2008)Risk factors in the development of Kaposi's sarcoma., In: AIDS22(13)pp. 1629-1632
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
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.

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.
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
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
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, 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
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
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
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
The innate type I interferon antiviral response is the first line of defence invoked to limit the spread of viral infections. Hence a number of viruses including Kaposi's sarcoma-associated herpesvirus (KSHV) have evolved defence strategies against this antiviral response. KSHV is the aetiologic agent of KS and almost one quarter of the KSHV genes specify either demonstrated or potential immunomodulatory activity including the four viral interferon regulatory factors (vIRFs). vIRFs 1, 2 and 3 have previously been shown to inhibit type I IFN signalling, whereas the inhibitory role of vIRF4 is yet to be reported. A previous stable isotope labelling of amino acids in cell culture (SILAC) study coupled to LC-MS/MS identified USP7 and ribosomal proteins as binding partners of both vIRF2 and vIRF4. The aim of the present study was to investigate the role of these binding partners in type I IFN signalling and to determine the regulatory mechanisms behind the effects of these partner proteins on the functions of the vIRF2 and vIRF4 proteins. Polysome profiling and microarray studies were carried out on vIRF4 expressing cells and suggested a novel regulatory role for vIRF4 in translation. USP7 was also characterised as a positive regulator of IFN signalling and the mechanism behind this effect was explored.