scholarly journals Human Gastro-Intestinal Graft-Versus-Host Disease Is Mediated By Retinoic Acid-Responsive CD8+ Effector T-Cells Under IL-23 Polarising Conditions

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 77-77
Author(s):  
Jennifer A Ball ◽  
Andrew James Clear ◽  
Maria Calaminici ◽  
Andrew Stagg ◽  
James Lindsay ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Subset ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Tissue Level ◽  
Cell Responses ◽  
Severe Stage ◽  
Skin Biopsies ◽  
The Impact

Abstract Background: Gastro-intestinal (GI) graft-versus-host disease (GvHD) results in significant morbidity and mortality after allogeneic hematopoietic stem cell transplantation (AHSCT). Retinoic acid (RA), a metabolite of vitamin A, has diverse effects on immune cells. RA signaling promotes immune tolerance under steady state conditions. However in pro-inflammatory conditions RA increases Th1, Th17 CD4+ and Tc1 CD8+ T cell responses and is implicated in the pathogenesis of autoimmune inflammatory bowel disease. Furthermore, RA exposure and RA-receptor alpha (RARα) signaling in allogeneic T cells potentiates GI-GvHD in mice. Thus RA and cytokines that influence the effect of RA on T cells may represent potential therapeutic targets for GI-GvHD. However, the impact of RA at a tissue level in human GI-GvHD is unknown. We therefore investigated the role of RA-responsive T cells in human GvHD in vivo and human allogeneic T-cell responses in vitro . Methods: We scrutinized GI biopsies from 47 patients after AHSCT (36 with and 11 without GI-GvHD confirmed by conventional histological criteria). We also analysed skin biopsies from 11 AHSCT patients. We used conventional immunohistochemistry and a novel deep phenotyping method using sequential staining, stripping and re-probing on the same fixed embedded biopsy to determine cellular co-expression of multiple markers to identify RA-responsive T cells in human GvHD biopsies at sites of GvHD damage. Finally, we used an HLA-mismatched allogeneic mixed lymphocyte co-culture (MLRs) system, combining CFSE dye dilution and multi-parameter flow cytometry to enable the phenotyping of alloproliferative T cells after manipulation of RA signalling. Results: Firstly we observed thatthe number of cells expressing high levels of cytoplasmic RA binding proteins I/II (a surrogate marker of RA) was increased in gut biopsies in patients with GI-GvHD versus controls (median 155 vs 43 cells/mm2, p=0.056). Importantly the number of cells expressing RARα was also significantly increased (median 1315 vs 544 cells/mm2, p=0.001) consistent with RA-responsiveness. Crucially the number of RARα+ cells correlated with clinical stage of acute GI-GvHD with higher numbers in patients with severe (stage 3-4) versus less severe (stage 1-2) disease. Having demonstrated that RA-responsive cells were associated with both occurrence and severity of GI-GvHD we went on to identify potential RA-responsive T cell subsets. Additionally, as IL-23 and IL-33 direct RA-programming of T cells to either pro-inflammatory or tolerogenic phenotypes we also measured cellular expression of these cytokines and their receptors. CD8+ T cells co-localized with RARα+ cells and were present in significantly increased numbers in gut biopsies from patients with GI-GvHD, as were Tbet+ Th1/Tc1 cells. In contrast, numbers of RORγ+ Th17 cells were unchanged and CD4+ cells were decreased. IL-23p19+ and IL-23R+ cell numbers were significantly increased in GI-GvHD biopsies, whereas IL33R (ST2+)cells were unchanged. In order to determine if the RA-responsive, CD8+ and IL-23R+ cells represented a single effector subset, we used sequential stripping/re-probing to deep phenotype the T cells. We identified a unique single CD8+ T-cell population that co-expressed RARα+, T-bet and IL23R, present in significantly increased numbers in gut biopsies from patients with GI-GvHD versus controls. This is consistent with a RA-responsive, IL-23-dependent, inflammatory Tc1 effector cell mediating tissue damage in human gut GvHD. Importantly, there was no increase in this T cell subset in skin biopsies of skin GvHD patients demonstrating tissue-specificity. Finally we determined the impact of exogenous RA exposure on T cell alloresponses in MLRs. RA significantly increased the proportion of alloproliferative effector CD8+ T cells co-expressing Tbet and gut-homing molecules, confirming that RA can directly potentiate human alloreactive CD8 T cell responses with capacity to home to the GI tract. Conclusions: This is the first data to demonstrate a role for RA at a tissue level in human GI-GvHD. Furthermore we have identified a gut specific CD8+ T cell subset which co-expresses RARα, T-bet, and IL-23R localised in areas of GI-damage likely to represent the RA-responsive effector cell. Therapeutic blockade of IL-23R could target this cellular response to prevent or treat GI-GvHD. Disclosures Gribben: Acerta: Honoraria; Janssen: Honoraria; Kite: Honoraria; Celgene: Honoraria; TG Therapeutics: Honoraria; Karyopharm: Honoraria; Pharmacyclics: Honoraria; Genentech/Roche: Honoraria; Abbvie: Honoraria.

scholarly journals Batf3-Dependent Dendritic Cells Promote Optimal CD8 T Cell Responses against Respiratory Poxvirus Infection

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Pritesh Desai ◽  
Vikas Tahiliani ◽  
Georges Abboud ◽  
Jessica Stanfield ◽  
Shahram Salek-Ardakani
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Vaccinia Virus ◽  
Respiratory Infection ◽  
Host Resistance ◽  
T Cell Responses ◽  
Cell Responses ◽  
Ifn Γ ◽  
The Impact

ABSTRACTRespiratory infection with vaccinia virus (VacV) elicits robust CD8+T cell responses that play an important role in host resistance. In the lung, VacV encounters multiple tissue-resident antigen-presenting cell (APC) populations, but which cell plays a dominant role in priming of virus-specific CD8+effector T cell responses remains poorly defined. We used Batf3−/−mice to investigate the impact of CD103+and CD8α+dendritic cell (DC) deficiency on anti-VacV CD8+T cell responses. We found that Batf3−/−mice were more susceptible to VacV infection, exhibiting profound weight loss, which correlated with impaired accumulation of gamma interferon (IFN-γ)-producing CD8+T cells in the lungs. This was largely due to defective priming since early in the response, antigen-specific CD8+T cells in the draining lymph nodes of Batf3−/−mice expressed significantly reduced levels of Ki67, CD25, and T-bet. These results underscore a specific role for Batf3-dependent DCs in regulating priming and expansion of effector CD8+T cells necessary for host resistance against acute respiratory VacV infection.IMPORTANCEDuring respiratory infection with vaccinia virus (VacV), a member ofPoxviridaefamily, CD8+T cells play important role in resolving the primary infection. Effector CD8+T cells clear the virus by accumulating in the infected lungs in large numbers and secreting molecules such as IFN-γ that kill virally infected cells. However, precise cell types that regulate the generation of effector CD8+T cells in the lungs are not well defined. Dendritic cells (DCs) are a heterogeneous population of immune cells that are recognized as key initiators and regulators of T-cell-mediated immunity. In this study, we reveal that a specific subset of DCs that are dependent on the transcription factor Batf3 for their development regulate the magnitude of CD8+T cell effector responses in the lungs, thereby providing protection during pulmonary VacV infection.

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

2005 ◽  
Vol 79 (15) ◽  
pp. 9419-9429 ◽  
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.

scholarly journals Protection against Vaccinia Virus Challenge by CD8 Memory T Cells Resolved by Molecular Mimicry

2006 ◽  
Vol 81 (2) ◽  
pp. 934-944 ◽  
Author(s):  
Markus Cornberg ◽  
Brian S. Sheridan ◽  
Frances M. Saccoccio ◽  
Michael A. Brehm ◽  
Liisa K. Selin
Keyword(s):  
T Cells ◽  
T Cell ◽  
Vaccinia Virus ◽  
Cd8 T Cells ◽  
Protective Immunity ◽  
Molecular Mimicry ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Epitopes ◽  
Cell Responses

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.

scholarly journals Adrenergic signaling controls early transcriptional programs during CD8+ T cell responses to viral infection

2021 ◽  
Author(s):  
Leonardo Estrada ◽  
Didem Agac Cobanoglu ◽  
Aaron Wise ◽  
Robert Maples ◽  
Murat Can Cobanoglu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Receptor Activation ◽  
Cell Development ◽  
Primary Response ◽  
Cell Responses

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.

scholarly journals Regulation of T Cell Responses by Ionic Salt Signals

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2365
Author(s):  
Christina E. Zielinski
Keyword(s):  
T Cells ◽  
T Cell ◽  
Sodium Chloride ◽  
T Cell Responses ◽  
T Helper Cell ◽  
Helper Cell ◽  
T Helper ◽  
Tissue Microenvironment ◽  
Cell Responses ◽  
The Impact

T helper cell responses are tailored to their respective antigens and adapted to their specific tissue microenvironment. While a great proportion of T cells acquire a resident identity, a significant proportion of T cells continue circulating, thus encountering changing microenvironmental signals during immune surveillance. One signal, which has previously been largely overlooked, is sodium chloride. It has been proposed to have potent effects on T cell responses in the context of autoimmune, allergic and infectious tissue inflammation in mouse models and humans. Sodium chloride is stringently regulated in the blood by the kidneys but displays differential deposition patterns in peripheral tissues. Sodium chloride accumulation might furthermore be regulated by dietary intake and thus by intentional behavior. Together, these results make sodium chloride an interesting but still controversial signal for immune modulation. Its downstream cellular activities represent a potential therapeutic target given its effects on T cell cytokine production. In this review article, we provide an overview and critical evaluation of the impact of this ionic signal on T helper cell polarization and T helper cell effector functions. In addition, the impact of sodium chloride from the tissue microenvironment is assessed for human health and disease and for its therapeutic potential.

scholarly journals Recruitment of highly functional SARS-CoV-2-specific CD8+ T cell receptors mediating cytotoxicity of virus-infected target cells in non-severe COVID-19

2021 ◽  
Author(s):  
Karolin I. Wagner ◽  
Laura M. Mateyka ◽  
Sebastian Jarosch ◽  
Vincent Grass ◽  
Simone Weber ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Hla Class I ◽  
Cd8 T Cell ◽  
Target Cells ◽  
Cell Responses ◽  
Cell Immunity ◽  
Engineered T Cells

T cell immunity is crucial for the control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and has been widely characterized on a quantitative level. In contrast, the quality of such T cell responses has been poorly investigated, in particular in the case of CD8+ T cells. Here, we explored the quality of SARS-CoV-2-specific CD8+ T cell responses in individuals who recovered from mild symptomatic infections, through which protective immunity should develop, by functional characterization of their T cell receptor (TCR) repertoire. CD8+ T cell responses specific for SARS-CoV-2-derived epitopes were low in frequency but could be detected robustly early as well as late - up to twelve months - after infection. A pool of immunodominant epitopes, which accurately identified previous SARSCoV- 2 infections, was used to isolate TCRs specific for epitopes restricted by common HLA class I molecules. TCR-engineered T cells showed heterogeneous functional avidity and cytotoxicity towards virus-infected target cells. High TCR functionality correlated with gene signatures of T cell function and activation that, remarkably, could be retrieved for each epitope:HLA combination and patient analyzed. Overall, our data demonstrate that highly functional HLA class I TCRs are recruited and maintained upon mild SARS-CoV-2 infection. Such validated epitopes and TCRs could become valuable tools for the development of diagnostic tests determining the quality of SARS-CoV-2-specific CD8+ T cell immunity, and thereby investigating correlates of protection, as well as to restore functional immunity through therapeutic transfer of TCR-engineered T cells.

scholarly journals Modulation of let-7 miRNAs controls the differentiation of effector CD8 T cells

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Alexandria C Wells ◽  
Keith A Daniels ◽  
Constance C Angelou ◽  
Eric Fagerberg ◽  
Amy S Burnside ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Receptor ◽  
Activated T Cells ◽  
Cell Responses

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.

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 ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Single Cell ◽  
Cd8 T Cells ◽  
Natural Infection ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Cell Responses

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.

scholarly journals TLR3 essentially promotes protective class I–restricted memory CD8+ T-cell responses to Aspergillus fumigatus in hematopoietic transplanted patients

Blood ◽  
2012 ◽  
Vol 119 (4) ◽  
pp. 967-977 ◽  
Author(s):  
Agostinho Carvalho ◽  
Antonella De Luca ◽  
Silvia Bozza ◽  
Cristina Cunha ◽  
Carmen D'Angelo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Aspergillus Fumigatus ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Class I ◽  
Class I Mhc ◽  
Cell Responses ◽  
Memory Cd8 T Cell

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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