Single dose of BNT162b2 mRNA vaccine against SARS-CoV-2 induces high frequency of neutralising antibody and polyfunctional T-cell responses in patients with myeloproliferative neoplasms

Encouraging results have been observed from initial studies evaluating vaccines targeting the novel beta coronavirus which causes severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, concerns have been raised around the efficacy of these vaccines in immunosuppressed populations, including patients with haematological malignancy. Myeloproliferative neoplasms (MPN), in particular myelofibrosis (MF), are associated with heterogenous immune defects which are influenced by patient age, disease subtype and the use of cytoreductive therapies. Patients with a WHO defined diagnosis of an MPN presenting to our clinic were recruited following first injection of 30μg BNT162b2. A positive anti-S IgG ELISA was seen in 76.1% (16) of patients following vaccination with positive neutralising antibodies detected in 85.7% (18) of patients. A memory T cell response was observed in 80% (16) of patients, with a CD4+ T cell response in 75% (15) and a CD8+ T cell response in 35% (7). These results, for the first time, provide some reassurance regarding the initial immune response to the BNT162b2 vaccine amongst patients with MPN, with response rates similar to that observed in the general population.

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Targeting cancer-associated fibroblast-secreted WNT2 restores dendritic cell-mediated antitumour immunity

Gut ◽

10.1136/gutjnl-2020-322924 ◽

2021 ◽

pp. gutjnl-2020-322924

Author(s):

Tuxiong Huang ◽

Xiang-Yu Tan ◽

Hui-Si Huang ◽

Yu-Ting Li ◽

Bei-Lei Liu ◽

...

Keyword(s):

T Cell ◽

Dendritic Cell ◽

Cell Response ◽

T Cell Responses ◽

Tumour Microenvironment ◽

T Cell Response ◽

Cell Responses ◽

Cancer Associated Fibroblast ◽

Anticancer Immunotherapy ◽

Novel Therapeutic Strategies

ObjectiveSolid tumours respond poorly to immune checkpoint inhibitor (ICI) therapies. One major therapeutic obstacle is the immunosuppressive tumour microenvironment (TME). Cancer-associated fibroblasts (CAFs) are a key component of the TME and negatively regulate antitumour T-cell response. Here, we aimed to uncover the mechanism underlying CAFs-mediated tumour immune evasion and to develop novel therapeutic strategies targeting CAFs for enhancing ICI efficacy in oesophageal squamous cell carcinoma (OSCC) and colorectal cancer (CRC).DesignAnti-WNT2 monoclonal antibody (mAb) was used to treat immunocompetent C57BL/6 mice bearing subcutaneously grafted mEC25 or CMT93 alone or combined with anti-programmed cell death protein 1 (PD-1), and the antitumour efficiency and immune response were assessed. CAFs-induced suppression of dendritic cell (DC)-differentiation and DC-mediated antitumour immunity were analysed by interfering with CAFs-derived WNT2, either by anti-WNT2 mAb or with short hairpin RNA-mediated knockdown. The molecular mechanism underlying CAFs-induced DC suppression was further explored by RNA-sequencing and western blot analyses.ResultsA negative correlation between WNT2+ CAFs and active CD8+ T cells was detected in primary OSCC tumours. Anti-WNT2 mAb significantly restored antitumour T-cell responses within tumours and enhanced the efficacy of anti-PD-1 by increasing active DC in both mouse OSCC and CRC syngeneic tumour models. Directly interfering with CAFs-derived WNT2 restored DC differentiation and DC-mediated antitumour T-cell responses. Mechanistic analyses further demonstrated that CAFs-secreted WNT2 suppresses the DC-mediated antitumour T-cell response via the SOCS3/p-JAK2/p-STAT3 signalling cascades.ConclusionsCAFs could suppress antitumour immunity through WNT2 secretion. Targeting WNT2 might enhance the ICI efficacy and represent a new anticancer immunotherapy.

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Role of Thymic Output in Regulating CD8 T-Cell Homeostasis during Acute and Chronic Viral Infection

Journal of Virology ◽

10.1128/jvi.79.15.9419-9429.2005 ◽

2005 ◽

Vol 79 (15) ◽

pp. 9419-9429 ◽

Cited By ~ 29

Author(s):

Nicole E. Miller ◽

Jennifer R. Bonczyk ◽

Yumi Nakayama ◽

M. Suresh

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

Viral Infections ◽

T Cell Responses ◽

Cd8 T Cell ◽

T Cell Response ◽

Cell Responses ◽

Lcmv Infection

ABSTRACT Although it is well documented that CD8 T cells play a critical role in controlling chronic viral infections, the mechanisms underlying the regulation of CD8 T-cell responses are not well understood. Using the mouse model of an acute and chronic lymphocytic choriomeningitis virus (LCMV) infection, we have examined the relative importance of peripheral T cells and thymic emigrants in the elicitation and maintenance of CD8 T-cell responses. Virus-specific CD8 T-cell responses were compared between mice that were either sham thymectomized or thymectomized (Thx) at ∼6 weeks of age. In an acute LCMV infection, thymic deficiency did not affect either the primary expansion of CD8 T cells or the proliferative renewal and maintenance of virus-specific lymphoid and nonlymphoid memory CD8 T cells. Following a chronic LCMV infection, in Thx mice, although the initial expansion of CD8 T cells was normal, the contraction phase of the CD8 T-cell response was exaggerated, which led to a transient but striking CD8 T-cell deficit on day 30 postinfection. However, the virus-specific CD8 T-cell response in Thx mice rebounded quickly and was maintained at normal levels thereafter, which indicated that the peripheral T-cell repertoire is quite robust and capable of sustaining an effective CD8 T-cell response in the absence of thymic output during a chronic LCMV infection. Taken together, these findings should further our understanding of the regulation of CD8 T-cell homeostasis in acute and chronic viral infections and might have implications in the development of immunotherapy.

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Listeria Monocytogenes: A Model Pathogen Continues to Refine Our Knowledge of the CD8 T Cell Response

Pathogens ◽

10.3390/pathogens7020055 ◽

2018 ◽

Vol 7 (2) ◽

pp. 55 ◽

Cited By ~ 11

Author(s):

Zhijuan Qiu ◽

Camille Khairallah ◽

Brian Sheridan

Keyword(s):

Listeria Monocytogenes ◽

T Cell ◽

Cell Response ◽

Protective Immunity ◽

T Cell Responses ◽

Cd8 T Cell ◽

Oral Infection ◽

T Cell Response ◽

Infection Model ◽

Cell Responses

Listeria monocytogenes (Lm) infection induces robust CD8 T cell responses, which play a critical role in resolving Lm during primary infection and provide protective immunity to re-infections. Comprehensive studies have been conducted to delineate the CD8 T cell response after Lm infection. In this review, the generation of the CD8 T cell response to Lm infection will be discussed. The role of dendritic cell subsets in acquiring and presenting Lm antigens to CD8 T cells and the events that occur during T cell priming and activation will be addressed. CD8 T cell expansion, differentiation and contraction as well as the signals that regulate these processes during Lm infection will be explored. Finally, the formation of memory CD8 T cell subsets in the circulation and in the intestine will be analyzed. Recently, the study of CD8 T cell responses to Lm infection has begun to shift focus from the intravenous infection model to a natural oral infection model as the humanized mouse and murinized Lm have become readily available. Recent findings in the generation of CD8 T cell responses to oral infection using murinized Lm will be explored throughout the review. Finally, CD8 T cell-mediated protective immunity against Lm infection and the use of Lm as a vaccine vector for cancer immunotherapy will be highlighted. Overall, this review will provide detailed knowledge on the biology of CD8 T cell responses after Lm infection that may shed light on improving rational vaccine design.

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Public T-cell epitopes shared among SARS-CoV-2 variants are presented on prevalent HLA class I alleles

10.1101/2021.10.13.463911 ◽

2021 ◽

Author(s):

Saskia Meyer ◽

Isaac Blaas ◽

Ravi Chand Bollineni ◽

Marina Delic-Sarac ◽

Trung T Tran ◽

...

Keyword(s):

T Cell ◽

Cell Response ◽

T Cell Responses ◽

Hla Class I ◽

Cd8 T Cell ◽

T Cell Response ◽

Class I ◽

T Cell Epitopes ◽

Low Frequencies ◽

Cell Responses

T-cell epitopes with broad population coverage may form the basis for a new generation of SARS-CoV-2 vaccines. However, published studies on immunoprevalence are limited by small test cohorts, low frequencies of antigen-specific cells and lack of data correlating eluted HLA ligands with T-cell responsiveness. Here, we investigate CD8 T-cell responses to 48 peptides eluted from prevalent HLA alleles, and an additional 84 predicted binders, in a large cohort of convalescents (n=83) and pre-pandemic control samples (n=19). We identify nine conserved SARS-CoV-2 specific epitopes restricted by four of the most prevalent HLA class I alleles in Caucasians, to which responding CD8 T cells are detected in 70-100% of convalescents expressing the relevant HLA allele, including two novel epitopes. We find a strong correlation between immunoprevalence and immunodominance. Using a new algorithm, we predict that a vaccine including these epitopes would induce a T cell response in 83% of Caucasians. Significance Statement: Vaccines that induce broad T-cell responses may boost immunity as protection from current vaccines against SARS-CoV-2 is waning. From a manufacturing standpoint, and to deliver the highest possible dose of the most immunogenic antigens, it is rational to limit the number of epitopes to those inducing the strongest immune responses in the highest proportion of individuals in a population. Our data show that the CD8 T cell response to SARS-CoV-2 is more focused than previously believed. We identify nine conserved SARS-CoV-2 specific CD8 T cell epitopes restricted by four of the most prevalent HLA class I alleles in Caucasians and demonstrate that seven of these are endogenously presented.

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Mononucleosis and Antigen-Driven T Cell Responses Have Different Requirements for Interleukin-2 Signaling in Murine Gammaherpesvirus Infection

Journal of Virology ◽

10.1128/jvi.00856-10 ◽

2010 ◽

Vol 84 (20) ◽

pp. 10923-10927 ◽

Cited By ~ 1

Author(s):

Michael Molloy ◽

Weijun Zhang ◽

Edward Usherwood

Keyword(s):

T Cell ◽

Cell Response ◽

Interleukin 2 ◽

T Cell Responses ◽

T Cell Response ◽

Long Term Memory ◽

Murine Gammaherpesvirus ◽

Cell Responses ◽

Gammaherpesvirus 68 ◽

Murine Gammaherpesvirus 68

ABSTRACT Interleukin-2 (IL-2) has been implicated as being necessary for the optimal formation of primary CD8+ T cell responses against various pathogens. Here we have examined the role that IL-2 signaling plays in several aspects of a CD8+ T cell response against murine gammaherpesvirus 68 (MHV-68). Exposure to MHV-68 causes a persistent infection, along with infectious mononucleosis, providing a model for studying these processes in mice. Our study indicates that CD25 is necessary for optimal expansion of the antigen-specific CD8+ T cell response but not for the long-term memory response. Contrastingly, IL-2 signaling through CD25 is absolutely required for CD8+ T cell mononucleosis.

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DNA gag/Adenovirus Type 5 (Ad5) gag and Ad5 gag/Ad5 gag Vaccines Induce Distinct T-Cell Response Profiles

Journal of Virology ◽

10.1128/jvi.00620-08 ◽

2008 ◽

Vol 82 (16) ◽

pp. 8161-8171 ◽

Cited By ~ 40

Author(s):

Kara S. Cox ◽

James H. Clair ◽

Michael T. Prokop ◽

Kara J. Sykes ◽

Sheri A. Dubey ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Response ◽

T Cell Responses ◽

Adenovirus Type ◽

T Cell Response ◽

Cell Responses ◽

Response Profiles ◽

Adenovirus Type 5 ◽

Hiv 1

ABSTRACT Results from Merck's phase II adenovirus type 5 (Ad5) gag/pol/nef test-of-concept trial showed that the vaccine lacked efficacy against human immunodeficiency virus (HIV) infection in a high-risk population. Among the many questions to be explored following this outcome are whether (i) the Ad5 vaccine induced the quality of T-cell responses necessary for efficacy and (ii) the lack of efficacy in the Ad5 vaccine can be generalized to other vector approaches intended to induce HIV type 1 (HIV-1)-specific T-cell responses. Here we present a comprehensive evaluation of the T-cell response profiles from cohorts of clinical trial subjects who received the HIV CAM-1 gag insert delivered by either a regimen with DNA priming followed by Ad5 boosting (n = 50) or a homologous Ad5/Ad5 prime-boost regimen (n = 70). The samples were tested using a statistically qualified nine-color intracellular cytokine staining assay measuring interleukin-2 (IL-2), tumor necrosis factor alpha, macrophage inflammatory protein 1β, and gamma interferon production and expression of CD107a. Both vaccine regimens induced CD4+ and CD8+ HIV gag-specific T-cell responses which variably expressed several intracellular markers. Several trends were observed in which the frequencies of HIV-1-specific CD4+ T cells and IL-2 production from antigen-specific CD8+ T cells in the DNA/Ad5 cohort were more pronounced than in the Ad5/Ad5 cohort. Implications of these results for future vaccine development will be discussed.

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Sustained Specific and Cross-Reactive T Cell Responses to Zika and Dengue Virus NS3 in West Africa

Journal of Virology ◽

10.1128/jvi.01992-17 ◽

2018 ◽

Vol 92 (7) ◽

Cited By ~ 16

Author(s):

Bobby Brooke Herrera ◽

Wen-Yang Tsai ◽

Charlotte A. Chang ◽

Donald J. Hamel ◽

Wei-Kung Wang ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Dengue Virus ◽

Zika Virus ◽

Cell Response ◽

Vaccine Development ◽

T Cell Responses ◽

T Cell Response ◽

Zikv Infection ◽

Cell Responses

ABSTRACT Recent studies on the role of T cells in Zika virus (ZIKV) infection have shown that T cell responses to Asian ZIKV infection are important for protection, and that previous dengue virus (DENV) exposure amplifies the protective T cell response to Asian ZIKV. Human T cell responses to African ZIKV infection, however, remain unexplored. Here, we utilized the modified anthrax toxin delivery system to develop a flavivirus enzyme-linked immunosorbent spot (ELISPOT) assay. Using human ZIKV and DENV samples from Senegal, West Africa, our results demonstrate specific and cross-reactive T cell responses to nonstructural protein 3 (NS3). Specifically, we found that T cell responses to NS3 protease are ZIKV and DENV specific, but responses to NS3 helicase are cross-reactive. Sequential sample analyses revealed immune responses sustained many years after infection. These results have important implications for African ZIKV/DENV vaccine development, as well as for potential flavivirus diagnostics based on T cell responses. IMPORTANCE The recent Zika virus (ZIKV) epidemic in Latin America and the associated congenital microcephaly and Guillain-Barré syndrome have raised questions as to why we have not recognized these distinct clinical diseases in Africa. The human immunologic response to ZIKV and related flaviviruses in Africa represents a research gap that may shed light on the mechanisms contributing to protection. The goal of our study was to develop an inexpensive assay to detect and characterize the T cell response to African ZIKV and DENV. Our data show long-term specific and cross-reactive human immune responses against African ZIKV and DENV, suggesting the usefulness of a diagnostic based on the T cell response. Additionally, we show that prior flavivirus exposure influences the magnitude of the T cell response. The identification of immune responses to African ZIKV and DENV is of relevance to vaccine development.

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Activation-induced Markers Detect Vaccine-Specific CD4+ T Cell Responses Not Measured by Assays Conventionally Used in Clinical Trials

Vaccines ◽

10.3390/vaccines6030050 ◽

2018 ◽

Vol 6 (3) ◽

pp. 50 ◽

Cited By ~ 6

Author(s):

Georgina Bowyer ◽

Tommy Rampling ◽

Jonathan Powlson ◽

Richard Morter ◽

Daniel Wright ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Response ◽

Viral Vectors ◽

Comprehensive Evaluation ◽

T Cell Responses ◽

T Cell Response ◽

Cell Responses ◽

Vaccine Immunogenicity ◽

Sensitivity Specificity

Immunogenicity of T cell-inducing vaccines, such as viral vectors or DNA vaccines and Bacillus Calmette-Guérin (BCG), are frequently assessed by cytokine-based approaches. While these are sensitive methods that have shown correlates of protection in various vaccine studies, they only identify a small proportion of the vaccine-specific T cell response. Responses to vaccination are likely to be heterogeneous, particularly when comparing prime and boost or assessing vaccine performance across diverse populations. Activation-induced markers (AIM) can provide a broader view of the total antigen-specific T cell response to enable a more comprehensive evaluation of vaccine immunogenicity. We tested an AIM assay for the detection of vaccine-specific CD4+ and CD8+ T cell responses in healthy UK adults vaccinated with viral vectored Ebola vaccine candidates, ChAd3-EBO-Z and MVA-EBO-Z. We used the markers, CD25, CD134 (OX40), CD274 (PDL1), and CD107a, to sensitively identify vaccine-responsive T cells. We compared the use of OX40+CD25+ and OX40+PDL1+ in CD4+ T cells and OX40+CD25+ and CD25+CD107a+ in CD8+ T cells for their sensitivity, specificity, and associations with other measures of vaccine immunogenicity. We show that activation-induced markers can be used as an additional method of demonstrating vaccine immunogenicity, providing a broader picture of the global T cell response to vaccination.

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Ex Vivo Profiling of CD8+-T-Cell Responses to Human Cytomegalovirus Reveals Broad and Multispecific Reactivities in Healthy Virus Carriers

Journal of Virology ◽

10.1128/jvi.77.9.5226-5240.2003 ◽

2003 ◽

Vol 77 (9) ◽

pp. 5226-5240 ◽

Cited By ~ 230

Author(s):

Rebecca Elkington ◽

Susan Walker ◽

Tania Crough ◽

Moira Menzies ◽

Judy Tellam ◽

...

Keyword(s):

T Cell ◽

Human Cytomegalovirus ◽

Cell Response ◽

Ex Vivo ◽

T Cell Responses ◽

T Cell Response ◽

Peptide Epitopes ◽

Cell Responses ◽

Hcmv Disease ◽

Early Late

ABSTRACT Human cytomegalovirus (HCMV) can establish both nonproductive (latent) and productive (lytic) infections. Many of the proteins expressed during these phases of infection could be expected to be targets of the immune response; however, much of our understanding of the CD8+-T-cell response to HCMV is mainly based on the pp65 antigen. Very little is known about T-cell control over other antigens expressed during the different stages of virus infection; this imbalance in our understanding undermines the importance of these antigens in several aspects of HCMV disease pathogenesis. In the present study, an efficient and rapid strategy based on predictive bioinformatics and ex vivo functional T-cell assays was adopted to profile CD8+-T-cell responses to a large panel of HCMV antigens expressed during different phases of replication. These studies revealed that CD8+-T-cell responses to HCMV often contained multiple antigen-specific reactivities, which were not just constrained to the previously identified pp65 or IE-1 antigens. Unexpectedly, a number of viral proteins including structural, early/late antigens and HCMV-encoded immunomodulators (pp28, pp50, gH, gB, US2, US3, US6, and UL18) were also identified as potential targets for HCMV-specific CD8+-T-cell immunity. Based on this extensive analysis, numerous novel HCMV peptide epitopes and their HLA-restricting determinants recognized by these T cells have been defined. These observations contrast with previous findings that viral interference with the antigen-processing pathway during lytic infection would render immediate-early and early/late proteins less immunogenic. This work strongly suggests that successful HCMV-specific immune control in healthy virus carriers is dependent on a strong T-cell response towards a broad repertoire of antigens.

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