scholarly journals Single cell profiling of T and B cell repertoires following SARS-CoV-2 mRNA vaccine

2021 ◽  
Author(s):  
Suhas Sureshchandra ◽  
Sloan A. Lewis ◽  
Brianna Doratt ◽  
Allen Jankeel ◽  
Izabela Ibraim ◽  
...  

mRNA based vaccines for SARS-CoV-2 have shown exceptional clinical efficacy providing robust protection against severe disease. However, our understanding of transcriptional and repertoire changes following full vaccination remains incomplete. We used single-cell RNA sequencing and functional assays to compare humoral and cellular responses to two doses of mRNA vaccine with responses observed in convalescent individuals with asymptomatic disease. Our analyses revealed enrichment of spike-specific B cells, activated CD4 T cells, and robust antigen-specific polyfunctional CD4 T cell responses in all vaccinees. On the other hand, CD8 T cell responses were both weak and variable. Interestingly, clonally expanded CD8 T cells were observed in every vaccinee, as observed following natural infection. TCR gene usage, however, was variable, reflecting the diversity of repertoires and MHC polymorphism in the human population. Natural infection induced expansion of larger CD8 T cell clones occupied distinct clusters, likely due to the recognition of a broader set of viral epitopes presented by the virus not seen in the mRNA vaccine. Our study highlights a coordinated adaptive immune response where early CD4 T cell responses facilitate the development of the B cell response and substantial expansion of effector CD8 T cells, together capable of contributing to future recall responses.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3533-3533
Author(s):  
Mathias Witzens-Harig ◽  
Dirk Hose ◽  
Michael Hundemer ◽  
Simone Juenger ◽  
Anthony D. Ho ◽  
...  

Abstract Introduction: The bone marrow (BM) is a site of induction of tumour antigen specific T cell responses in many malignancies. We have demonstrated in the BM of myeloma patients high frequencies of spontaneously generated CD8 memory T cells with specificity for the myeloma-associated antigen MUC1, which were not detectable in the peripheral blood (PB). Besides MUC1, carcinoembryonic antigen was recently identified as a tumour-associated antigen in a patient with multiple myeloma. Up to now, spontaneous CD4 T cell responses against myeloma-associated antigens have not been reported. We undertook this study to evaluate to what extent spontaneous CD4 T cell responses against myeloma antigens occur during myeloma progression and if MUC1 or carcinoembryonic antigen represent immunogenic targets of spontaneous CD4 and CD8 T cell responses. Methods: Altogether, 78 patients with multiple myeloma were included into the study. Presence of functionally competent antigen specific T cells was evaluated by ex vivo short term (40 h) IFN-γ Elispot analyses. CD4 T cell responses against MUC1 were assessed by stimulation of purified CD4 T cell fractions with antigen pulsed, autologous dendritic cells (DCs) pulsed with two synthetic 100 meric polypeptides (pp1-100ss and (137–157)5 tr) that can be processed and presented via multiple HLA-II alleles. CD4- or CD8 T cell reactivity against carcinoembryonic antigen was assessed on purified CD4- and CD8 T cell fractions by pulsing DCs with highly purified CEA derived from culture supernatants of an epithelial carcinoma cell line. CD8 responses against MUC1 were analyzed by stimulation of HLA-A2+ patients derived purified T cells with DCs loaded with HLA-A2 restricted MUC1-derived nonameric peptide LLLLTVLTV. As negative control antigen for MUC1 polypeptides and CEA human IgG was used for pulsing DCs at identical concentrations while HLA-A2-restricted peptide SLYNTVATL derived from HIV was used as control antigen for LLLLTVLTV. Test antigen specific reactivity was defined by significantly increased numbers of IFN-γ spots in triplicate test wells compared to control wells (p<0.05, students T test). Results: 8 out of 19 tested patients (42%) contained MUC1 specific CD8 T cells in their bone marrow, while MUC1 specific CD4 T cells were detected in the BM of 30% of the cases (3/10). Interestingly, in peripheral blood (PB) CD8 reactivity against MUC1 was detectable in only 1 out of 10 patients while CD4 reactivity in PB was not detectable at all (0/10). CEA was specifically recognized by BM CD8 T cells from 5 out of 30 patients (17%) and by BM CD4 T cells from 5 out of 18 patients (28%). CEA was not recognized by CD4 and CD8 T cells in the PB of the same patients (0/13). Conclusion: Spontaneous T helper responses against tumour-associated antigens occur in the BM at similar levels as antigen specific CD8 T cells responses while they are virtually undetectable in the PB. Compared to CEA, MUC1 induces CD8 T cell responses in a much higher proportion of myeloma patients. Nevertheless, our data suggest that CEA may trigger spontaneous T cell responses against multiple myeloma in a considerable number of patients. Thus, systematic functional analyses of this potential tumour antigen in multiple myeloma appears to be justified.


Blood ◽  
2005 ◽  
Vol 105 (3) ◽  
pp. 1170-1178 ◽  
Author(s):  
Arthur Y. Kim ◽  
Georg M. Lauer ◽  
Kei Ouchi ◽  
Marylyn M. Addo ◽  
Michaela Lucas ◽  
...  

AbstractCD8+ T-cell responses are an essential antiviral host defense in persistent viral infections, and their sustained effectiveness is thought to be critically dependent on CD4+ T-helper cells. To determine the relationship between HIV-1–induced CD4+ T-cell depletion and hepatitis C virus (HCV)–specific CD8+ T-cell responses during viral persistence, we studied 103 persons positive for HCV, 74 coinfected with HIV-1. CD8+ T-cell responses to the entire HCV polyprotein were determined by using an interferon-γ enzyme-linked immunospot (ELISpot) assay. Although HIV-1 infection by itself was not associated with a diminished HCV-specific response, HIV-1–associated CD4+ depletion was associated with significantly lower HCV-specific CD8+ T cells (R = 0.48, P &lt; .0001). In contrast, declining CD4+ counts over the same range were not associated with diminished Epstein-Barr virus (EBV)– (R = 0.19, P = .31) or HIV-1–specific (R = –0.13, P = .60) CD8+ T-cell responses in persons infected with all viruses. These data indicate that frequencies of circulating HCV-specific CD8+ T-cell responses are sensitive to absolute CD4+ T-cell counts and provide a possible explanation for the accelerated HCV disease course in persons coinfected with HIV-1 and HCV.


1998 ◽  
Vol 188 (12) ◽  
pp. 2205-2213 ◽  
Author(s):  
Allan J. Zajac ◽  
Joseph N. Blattman ◽  
Kaja Murali-Krishna ◽  
David J.D. Sourdive ◽  
M. Suresh ◽  
...  

We examined the regulation of virus-specific CD8 T cell responses during chronic lymphocytic choriomeningitis virus (LCMV) infection of mice. Our study shows that within the same persistently infected host, different mechanisms can operate to silence antiviral T cell responses; CD8 T cells specific to one dominant viral epitope were deleted, whereas CD8 T cells responding to another dominant epitope persisted indefinitely. These virus-specific CD8 T cells expressed activation markers (CD69hi, CD44hi, CD62Llo) and proliferated in vivo but were unable to elaborate any antiviral effector functions. This unresponsive phenotype was more pronounced under conditions of CD4 T cell deficiency, highlighting the importance of CD8– CD4 T cell collaboration in controlling persistent infections. Importantly, in the presence of CD4 T cell help, adequate CD8 effector activity was maintained and the chronic viral infection eventually resolved. The persistence of activated virus-specific CD8 T cells without effector function reveals a novel mechanism for silencing antiviral immune responses and also offers new possibilities for enhancing CD8 T cell immunity in chronically infected hosts.


2005 ◽  
Vol 79 (15) ◽  
pp. 9419-9429 ◽  
Author(s):  
Nicole E. Miller ◽  
Jennifer R. Bonczyk ◽  
Yumi Nakayama ◽  
M. Suresh

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.


2006 ◽  
Vol 81 (2) ◽  
pp. 934-944 ◽  
Author(s):  
Markus Cornberg ◽  
Brian S. Sheridan ◽  
Frances M. Saccoccio ◽  
Michael A. Brehm ◽  
Liisa K. Selin

ABSTRACT Live vaccinia virus (VV) vaccination has been highly successful in eradicating smallpox. However, the mechanisms of immunity involved in mediating this protective effect are still poorly understood, and the roles of CD8 T-cell responses in primary and secondary VV infections are not clearly identified. By applying the concept of molecular mimicry to identify potential CD8 T-cell epitopes that stimulate cross-reactive T cells specific to lymphocytic choriomeningitis virus (LCMV) and VV, we identified after screening only 115 peptides two VV-specific immunogenic epitopes that mediated protective immunity against VV. An immunodominant epitope, VV-e7r130, did not generate cross-reactive T-cell responses to LCMV, and a subdominant epitope, VV-a11r198, did generate cross-reactive responses to LCMV. Infection with VV induced strong epitope-specific responses which were stable into long-term memory and peaked at the time virus was cleared, consistent with CD8 T cells assisting in the control of VV. Two different approaches, direct adoptive transfer of VV-e7r-specific CD8 T cells and prior immunization with a VV-e7r-expressing ubiquitinated minigene, demonstrated that memory CD8 T cells alone could play a significant role in protective immunity against VV. These studies suggest that exploiting cross-reactive responses between viruses may be a useful tool to complement existing technology in predicting immunogenic epitopes to large viruses, such as VV, leading to a better understanding of the role CD8 T cells play during these viral infections.


2021 ◽  
Author(s):  
Leonardo Estrada ◽  
Didem Agac Cobanoglu ◽  
Aaron Wise ◽  
Robert Maples ◽  
Murat Can Cobanoglu ◽  
...  

Viral infections drive the expansion and differentiation of responding CD8+ T cells into variegated populations of cytolytic effector and memory cells. While pro-inflammatory cytokines and cell surface immune receptors play a key role in guiding T cell responses to infection, T cells are also markedly influenced by neurotransmitters. Norepinephrine is a key sympathetic neurotransmitter, which acts to suppress CD8 + T cell cytokine secretion and lytic activity by signaling through the beta2-adrenergic receptor (ADRB2). Although ADRB2 signaling is considered generally immunosuppressive, its role in regulating differentiation of effector T cells in response to infection has not been investigated. Using an adoptive transfer approach, we compared the expansion and differentiation of wild type (WT) to Adrb2-/- CD8 + T cells throughout the primary response to vesicular stomatitis virus (VSV) infection in vivo. We measured the dynamic changes in transcriptome profiles of antigen-specific CD8 + T cells as they responded to VSV. Within the first 7 days of infection, WT cells out-paced the expansion of Adrb2-/- cells, which correlated with reduced expression of IL-2 and the IL-2Ralpha; in the absence of ADRB2. RNASeq analysis identified over 300 differentially expressed genes that were both temporally regulated following infection and selectively regulated in WT vs Adrb2-/- cells. These genes contributed to major transcriptional pathways including cytokine receptor activation, signaling in cancer, immune deficiency, and neurotransmitter pathways. By parsing genes within groups that were either induced or repressed over time in response to infection, we identified three main branches of genes that were differentially regulated by the ADRB2. These gene sets were predicted to be regulated by specific transcription factors involved in effector T cell development, such as Tbx21 and Eomes. Collectively, these data demonstrate a significant role for ADRB2 signaling in regulating key transcriptional pathways during CD8 + T cells responses to infection that may dramatically impact their functional capabilities and downstream memory cell development.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Alexandria C Wells ◽  
Keith A Daniels ◽  
Constance C Angelou ◽  
Eric Fagerberg ◽  
Amy S Burnside ◽  
...  

The differentiation of naive CD8 T cells into effector cytotoxic T lymphocytes upon antigen stimulation is necessary for successful antiviral, and antitumor immune responses. Here, using a mouse model, we describe a dual role for the let-7 microRNAs in the regulation of CD8 T cell responses, where maintenance of the naive phenotype in CD8 T cells requires high levels of let-7 expression, while generation of cytotoxic T lymphocytes depends upon T cell receptor-mediated let-7 downregulation. Decrease of let-7 expression in activated T cells enhances clonal expansion and the acquisition of effector function through derepression of the let-7 targets, including Myc and Eomesodermin. Ultimately, we have identified a novel let-7-mediated mechanism, which acts as a molecular brake controlling the magnitude of CD8 T cell responses.


Blood ◽  
2012 ◽  
Vol 119 (4) ◽  
pp. 967-977 ◽  
Author(s):  
Agostinho Carvalho ◽  
Antonella De Luca ◽  
Silvia Bozza ◽  
Cristina Cunha ◽  
Carmen D'Angelo ◽  
...  

Abstract Aspergillus fumigatus is a model fungal pathogen and a common cause of severe infections and diseases. CD8+ T cells are present in the human and murine T-cell repertoire to the fungus. However, CD8+ T-cell function in infection and the molecular mechanisms that control their priming and differentiation into effector and memory cells in vivo remain elusive. In the present study, we report that both CD4+ and CD8+ T cells mediate protective memory responses to the fungus contingent on the nature of the fungal vaccine. Mechanistically, class I MHC-restricted, CD8+ memory T cells were activated through TLR3 sensing of fungal RNA by cross-presenting dendritic cells. Genetic deficiency of TLR3 was associated with susceptibility to aspergillosis and concomitant failure to activate memory-protective CD8+ T cells both in mice and in patients receiving stem-cell transplantations. Therefore, TLR3 essentially promotes antifungal memory CD8+ T-cell responses and its deficiency is a novel susceptibility factor for aspergillosis in high-risk patients.


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