ORCID Profile
0000-0003-3545-3758
Current Organisation
University of Oxford
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Publisher: Elsevier BV
Date: 07-2022
Publisher: Elsevier BV
Date: 11-2021
Publisher: American Society for Microbiology
Date: 05-2005
DOI: 10.1128/JVI.79.9.5665-5675.2005
Abstract: T-cell responses to dengue viruses may be important in both protective immunity and pathogenesis. This study of 48 Vietnamese adults with secondary dengue virus infections defined the breadth and magnitude of peripheral T-cell responses to 260 overlapping peptide antigens derived from a dengue virus serotype 2 (DV2) isolate. Forty-seven different peptides evoked significant gamma interferon enzyme-linked immunospot (ELISPOT) assay responses in 39 patients of these, 34 peptides contained potentially novel T-cell epitopes. NS3 and particularly NS3 200-324 were important T-cell targets. The breadth and magnitude of ELISPOT responses to DV2 peptides were independent of the infecting dengue virus serotype, suggesting that cross-reactive T cells dominate the acute response during secondary infection. Acute ELISPOT responses were weakly correlated with the extent of hemoconcentration in in idual patients but not with the nadir of thrombocytopenia or overall clinical disease grade. NS3 556-564 and Env 414-422 were identified as novel HLA-A*24 and B*07-restricted CD8 + T-cell epitopes, respectively. Acute T-cell responses to natural variants of Env 414-422 and NS3 556-564 were largely cross-reactive and peaked during disease convalescence. The results highlight the importance of NS3 and cross-reactive T cells during acute secondary infection but suggest that the overall breadth and magnitude of the T-cell response is not significantly related to clinical disease grade.
Publisher: American Society of Hematology
Date: 07-07-2011
DOI: 10.1182/BLOOD-2010-06-291963
Abstract: Obstacles to developing an HIV-1 vaccine include extensive viral ersity and lack of correlates of protective immunity. High mutation rates allow HIV-1 to adapt rapidly to selective forces such as antiretroviral therapy and immune pressure, including HIV-1–specific CTLs that select viral variants which escape T-cell recognition. Multiple factors contribute to HIV-1 ersity, making it difficult to disentangle the contribution of CTL selection without using complex analytical approaches. We describe an HIV-1 outbreak in 231 former plasma donors in China, where a narrow-source virus that had contaminated the donation system was apparently transmitted to many persons contemporaneously. The genetic ergence now evident in these subjects should uniquely reveal how much viral ersity at the population level is solely attributable to host factors. We found significant correlations between pair-wise ergence of viral sequences and HLA class I genotypes across epitope-length windows in HIV-1 Gag, reverse transcriptase, integrase, and Nef, corresponding to sites of 140 HLA class I allele-associated viral polymorphisms. Of all polymorphic sites across these 4 proteins, 24%-56% were sites of HLA-associated selection. These data confirm that CTL pressure has a major effect on inter-host HIV-1 viral ersity and probably represents a key element of viral control.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Oxford University Press (OUP)
Date: 2010
DOI: 10.1086/648733
Abstract: Immune activation is a hallmark of disease progression in human immunodeficiency virus (HIV) type 1 (HIV-1) and HIV type 2 (HIV-2) infection. However, the relationship between viremia and systemic immune activation is unclear. We assessed the relationship between HIV-2 plasma virus load and immune system activation in a cross-sectional study in a community cohort of HIV-1-positive, HIV-2-positive, and HIV-negative patients, in which many HIV-2-positive patients had nonprogressing infection. HLA-DR and CD38 expression on CD4(+) and CD8(+) T cells was measured, as were plasma beta(2)-microglobulin levels. These markers were related to clinical (virus load and CD4(+) cell count) and immunological (HIV-2-specific interferon gamma secretion) correlates of delayed disease progression. A consistent positive correlation was identified between the level of HIV-2 viremia and immune activation. We propose that increasing virus load may contribute to systemic immune activation in HIV-2 infection.
Publisher: Elsevier BV
Date: 08-2020
Publisher: American Society for Clinical Investigation
Date: 10-2007
DOI: 10.1172/JCI32380
Publisher: Public Library of Science (PLoS)
Date: 05-12-2007
Publisher: American Society of Hematology
Date: 23-05-2013
DOI: 10.1182/BLOOD-2012-12-472787
Abstract: HIV-2 viral control is associated with a polyfunctional Gag-specific CD8+ T-cell response but not with perforin upregulation. Our findings provide insight into cellular immune responses associated with a naturally contained human retroviral infection.
Publisher: Rockefeller University Press
Date: 23-04-2007
DOI: 10.1084/JEM.20061381
Abstract: Dengue virus infection is an increasingly important tropical disease, causing 100 million cases each year. Symptoms range from mild febrile illness to severe hemorrhagic fever. The pathogenesis is incompletely understood, but immunopathology is thought to play a part, with antibody-dependent enhancement and massive immune activation of T cells and monocytes/macrophages leading to a disproportionate production of proinflammatory cytokines. We sought to investigate whether a defective population of regulatory T cells (T reg cells) could be contributing to immunopathology in severe dengue disease. CD4+CD25highFoxP3+ T reg cells of patients with acute dengue infection of different severities showed a conventional phenotype. Unexpectedly, their capacity to suppress T cell proliferation and to secrete interleukin-10 was not altered. Moreover, T reg cells suppressed the production of vasoactive cytokines after dengue-specific stimulation. Furthermore, T reg cell frequencies and also T reg cell/effector T cell ratios were increased in patients with acute infection. A strong indication that a relative rise of T reg cell/effector T cell ratios is beneficial for disease outcome comes from patients with mild disease in which this ratio is significantly increased (P & 0.0001) in contrast to severe cases (P = 0.2145). We conclude that although T reg cells expand and function normally in acute dengue infection, their relative frequencies are insufficient to control the immunopathology of severe disease.
Publisher: Springer Science and Business Media LLC
Date: 10-2009
Publisher: Elsevier BV
Date: 08-2020
Publisher: American Society for Microbiology
Date: 15-12-2009
DOI: 10.1128/JVI.01252-09
Abstract: Chronic immune activation is thought to play a major role in human immunodeficiency virus (HIV) pathogenesis, but the relative contributions of multiple factors to immune activation are not known. One proposed mechanism to protect against immune activation is the ability of Nef proteins from some HIV and simian immunodeficiency virus strains to downregulate the T-cell receptor (TCR)-CD3 complex of the infected cell, thereby reducing the potential for deleterious activation. HIV type 1 (HIV-1) Nef has lost this property. In contrast to HIV-1, HIV-2 infection is characterized by a marked disparity in the disease course, with most in iduals maintaining a normal life span. In this study, we examined the relationship between the ability of HIV-2 Nef proteins to downregulate the TCR and immune activation, comparing progressors and nonprogressors. Representative Nef variants were isolated from 28 HIV-2-infected in iduals. We assessed their abilities to downregulate the TCR from the surfaces of CD4 T cells. In the same in iduals, the activation of peripheral lymphocytes was evaluated by measurement of the expression levels of HLA-DR and CD38. We observed a striking correlation of the TCR downregulation efficiency of HIV-2 Nef variants with immune activation in in iduals with a low viral load. This strongly suggests that Nef expression can influence the activation state of the immune systems of infected in iduals. However, the efficiency of TCR downregulation by Nef was not reduced in progressing in iduals, showing that TCR downregulation does not protect against progression in HIV-2 infection.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 10-2013
Publisher: American Society for Clinical Investigation
Date: 18-09-2008
DOI: 10.1172/JCI32460
Publisher: Frontiers Media SA
Date: 05-03-2020
Publisher: Elsevier BV
Date: 03-2021
Publisher: American Association for Cancer Research (AACR)
Date: 08-2019
DOI: 10.1158/2326-6066.CIR-18-0885
Abstract: Immunotherapy treatments with anti-PD-1 boost recovery in less than 30% of treated cancer patients, indicating the complexity of the tumor microenvironment. Expression of HLA-E is linked to poor clinical outcomes in mice and human patients. However, the contributions to immune evasion of HLA-E, a ligand for the inhibitory CD94/NKG2A receptor, when expressed on tumors, compared with adjacent tissue and peripheral blood mononuclear cells, remains unclear. In this study, we report that epithelial-derived cancer cells, tumor macrophages, and CD141+ conventional dendritic cells (cDC) contributed to HLA-E enrichment in carcinomas. Different cancer types showed a similar pattern of enrichment. Enrichment correlated to NKG2A upregulation on CD8+ tumor-infiltrating T lymphocytes (TIL) but not on CD4+ TILs. CD94/NKG2A is exclusively expressed on PD-1high TILs while lacking intratumoral CD103 expression. We also found that the presence of CD94/NKG2A on human tumor–specific T cells impairs IL2 receptor–dependent proliferation, which affects IFNγ-mediated responses and antitumor cytotoxicity. These functionalities recover following antibody-mediated blockade in vitro and ex vivo. Our results suggest that enriched HLA-E:CD94/NKG2A inhibitory interaction can impair survival of PD-1high TILs in the tumor microenvironment.
Publisher: Wiley
Date: 04-2008
Publisher: Research Square Platform LLC
Date: 27-07-2021
DOI: 10.21203/RS.3.RS-734011/V1
Abstract: NP 105-113 -B*07:02 specific CD8 + T-cell responses are considered among the most dominant in SARS-CoV-2-infected in iduals. We found strong association of this response with mild disease. Analysis of NP 105-113 -B*07:02 specific T-cell clones and single cell sequencing were performed concurrently, with functional avidity and anti-viral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with TCR usage, transcriptome signature, and disease severity (acute N=77, convalescent N=52). We demonstrated a beneficial association of NP 105-113 -B*07:02 specific T-cells in COVID-19 disease progression, linked with expansion of T-cell precursors, high functional avidity and anti-viral effector function. Broad immune memory pools were narrowed post-infection but NP 105-113 -B*07:02 specific T-cells were maintained 6 months after infection with preserved anti-viral efficacy to the SARS-CoV-2 Victoria strain, as well as new Alpha, Beta and Gamma variants. Our data shows that NP 105-113 -B*07:02 specific T-cell responses associate with mild disease and high anti-viral efficacy, pointing to inclusion for future vaccine design.
Publisher: American Association for Cancer Research (AACR)
Date: 02-2020
DOI: 10.1158/2326-6066.CIR-19-0554
Abstract: Enrichment of CD103+ tumor-infiltrating T lymphocytes (TIL) is associated with improved outcomes in patients. However, the characteristics of human CD103+ cytotoxic CD8+ T cells (CTL) and their role in tumor control remain unclear. We investigated the features and antitumor mechanisms of CD103+ CTLs by assessing T-cell receptor (TCR)–matched CD103+ and CD103− cancer-specific CTL immunity in vitro and its immunophenotype ex vivo. Interestingly, we found that differentiated CD103+ cancer-specific CTLs expressed the active form of TGFβ1 to continually self-regulate CD103 expression, without relying on external TGFβ1-producing cells. The presence of CD103 on CTLs improved TCR antigen sensitivity, which enabled faster cancer recognition and rapid antitumor cytotoxicity. These CD103+ CTLs had elevated energetic potential and faster migration capacity. However, they had increased inhibitory receptor coexpression and elevated T-cell apoptosis following prolonged cancer exposure. Our data provide fundamental insights into the properties of matured human CD103+ cancer-specific CTLs, which could have important implications for future designs of tissue-localized cancer immunotherapy strategies.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-1998
Publisher: Springer Science and Business Media LLC
Date: 29-01-2013
DOI: 10.1038/NCOMMS2433
Publisher: Springer Science and Business Media LLC
Date: 12-2021
DOI: 10.1038/S41590-021-01084-Z
Abstract: NP 105–113 -B*07:02-specific CD8 + T cell responses are considered among the most dominant in SARS-CoV-2-infected in iduals. We found strong association of this response with mild disease. Analysis of NP 105–113 -B*07:02-specific T cell clones and single-cell sequencing were performed concurrently, with functional avidity and antiviral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with T cell receptor usage, transcriptome signature and disease severity (acute n = 77, convalescent n = 52). We demonstrated a beneficial association of NP 105–113 -B*07:02-specific T cells in COVID-19 disease progression, linked with expansion of T cell precursors, high functional avidity and antiviral effector function. Broad immune memory pools were narrowed postinfection but NP 105–113 -B*07:02-specific T cells were maintained 6 months after infection with preserved antiviral efficacy to the SARS-CoV-2 Victoria strain, as well as Alpha, Beta, Gamma and Delta variants. Our data show that NP 105–113 -B*07:02-specific T cell responses associate with mild disease and high antiviral efficacy, pointing to inclusion for future vaccine design.
Publisher: Springer Science and Business Media LLC
Date: 17-12-2020
Publisher: Elsevier BV
Date: 12-2020
Publisher: Wiley
Date: 24-06-2015
Publisher: Springer Science and Business Media LLC
Date: 17-12-2020
Publisher: Wiley
Date: 25-06-2010
Abstract: HIV-1-specific CD8(+) T cells are present in most HIV-1-infected people and play an important role in controlling viral replication, but the characteristics of an effective HIV-specific T-cell response are largely unknown. The majority of HIV-2-infected people behave as long-term non-progressors while those who progress to AIDS do so in a manner indistinguishable from HIV-1. A detailed study of HIV-2 infection may identify protective immune responses. Robust gag p26-specific T-cell responses are elicited during HIV-2 infection and correlate with control of viremia. In this study, we analyzed features of an HLA-B 3501-restricted T-cell response to HIV-2 p26 that may contribute to virus control. In contrast to HIV-1, HIV-2-specific T cells are at an early stage of differentiation (CD27(+)CD28(+)), a finding that relates directly to CD4(+) T-cell levels and inversely to immune activation. The cells demonstrate IFN-gamma secretion, oligoclonal T-cell receptor Vbeta gene segment usage, exceptional avidity and secretion of pro-inflammatory cytokines. Despite the potentially strong selection pressure imposed on the virus by these cells, there was no evidence of HIV-2 sequence evolution. We propose that in chronic HIV-2 infection, the maintenance of early-differentiated, highly avid CD8(+) T cells could account for the non-progressive course of disease. Such responses may be desirable from an HIV vaccine.
Publisher: Springer Science and Business Media LLC
Date: 25-05-2020
DOI: 10.1038/S41423-020-0468-X
Abstract: In this review, we will highlight the importance of cancer germline antigen-specific cytotoxic CD8 + T lymphocytes (CTL) and the factors affecting antitumor CTL responses. In light of cancer immunotherapy, we will emphasis the need to further understand the features, characteristics, and actions of modulatory receptors of human cancer germline-specific CTLs, in order to determine the optimal conditions for antitumor CTL responses.
Publisher: Springer Science and Business Media LLC
Date: 17-08-2021
DOI: 10.1038/S41467-021-25167-5
Abstract: The extent to which immune responses to natural infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and immunization with vaccines protect against variants of concern (VOC) is of increasing importance. Accordingly, here we analyse antibodies and T cells of a recently vaccinated, UK cohort, alongside those recovering from natural infection in early 2020. We show that neutralization of the VOC compared to a reference isolate of the original circulating lineage, B, is reduced: more profoundly against B.1.351 than for B.1.1.7, and in responses to infection or a single dose of vaccine than to a second dose of vaccine. Importantly, high magnitude T cell responses are generated after two vaccine doses, with the majority of the T cell response directed against epitopes that are conserved between the prototype isolate B and the VOC. Vaccination is required to generate high potency immune responses to protect against these and other emergent variants.
Publisher: The American Association of Immunologists
Date: 15-06-2010
Abstract: Immune activation is a feature of dengue hemorrhagic fever (DHF) and CD8+ T cell responses in particular have been suggested as having a role in the vasculopathy that characterizes this disease. By phenotyping CD8+ T cells (CD38+/HLA-DR+, CD38+/Ki-67+, or HLA-DR+/Ki-67+) in serial blood s les from children with dengue, we found no evidence of increased CD8+ T cell activation prior to the commencement of resolution of viremia or hemoconcentration. Investigations with MHC class I tetramers to detect NS3133–142-specific CD8+ T cells in two independent cohorts of children suggested the commencement of hemoconcentration and thrombocytopenia in DHF patients generally begins before the appearance of measurable frequencies of NS3133–142-specific CD8+ T cells. The temporal mismatch between the appearance of measurable surface activated or NS3133–142-specific CD8+ T cells suggests that these cells are sequestered at sites of infection, have phenotypes not detected by our approach, or that other mechanisms independent of CD8+ T cells are responsible for early triggering of capillary leakage in children with DHF.
Publisher: Springer Science and Business Media LLC
Date: 25-09-2017
DOI: 10.1038/NI.3850
Abstract: Adaptive immune responses protect against infection with dengue virus (DENV), yet cross-reactivity with distinct serotypes can precipitate life-threatening clinical disease. We found that clonotypes expressing the T cell antigen receptor (TCR) β-chain variable region 11 (TRBV11-2) were 'preferentially' activated and mobilized within immunodominant human-leukocyte-antigen-(HLA)-A*11:01-restricted CD8
Publisher: Elsevier BV
Date: 03-2022
Publisher: Springer Science and Business Media LLC
Date: 06-05-2021
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Tao Dong.