scholarly journals SARS-CoV-2 responsive T cell numbers are associated with protection from COVID-19: A prospective cohort study in keyworkers

2020 ◽  
Author(s):  
David Wyllie ◽  
Ranya Mulchandani ◽  
Hayley E Jones ◽  
Sian Taylor-Phillips ◽  
Tim Brooks ◽  
...  
Keyword(s):  
T Cells ◽  
Cohort Study ◽  
T Cell ◽  
Prospective Cohort Study ◽  
Peripheral Blood ◽  
Prospective Cohort ◽  
T Cell Responses ◽  
Cell Numbers ◽  
Cell Responses ◽  
Immune Correlates

AbstractBackgroundImmune correlates of protection from COVID-19 are important, but incompletely understood.MethodsWe conducted a prospective cohort study in 2,826 participants working in hospitals and Fire and Police services in England, UK during the pandemic(ISRCTN5660922). Of these, 2,672 were unselected volunteers recruited irrespective of previous SARS-CoV-2 RT-PCR test results, and 154 others were recruited separately specifically because they previously tested positive. At recruitment in June 2020, we measured numbers of interferon-γ secreting, SARS-CoV-2 responsive T cells using T-SPOT®Discovery SARS-CoV-2 kits (Oxford Immunotec Ltd), and antibodies to SARS-CoV-2 proteins using commercial immunoassays. We then described time to microbiologically confirmed SARS-CoV-2 infection, stratified by immunological parameters.ResultsT cells responsive to the spike (S), nuclear (N) and membrane proteins (M) dominated the responses measured. Using the sum of the spots (responsive cells within each well of 250,000 peripheral blood mononuclear cells) for S, N and M antigens minus the control, the 2,672 unselected participants were divided into those with higher responses (n=669, 25.4%; median 30 spots (IQR 18,54)) and those with low responses (n=2016, 76.7%, median 3 (IQR 1,6)), the cutoff we derived being 12 spots. Of the participants with higher T cell responses, 367 (53%) had detectable antibodies against the N or S proteins. During a median of 118 days follow-up, 20 participants with lower T cell responses developed COVID-19, compared with none in the population with high T cell responses (log-rank test, p=6×10−3).ConclusionsPeripheral blood SARS-CoV-2 responsive T cell numbers are associated with risk of developing COVID-19.

scholarly journals Longitudinal Analysis of Memory B and T Cell Responses to Dengue Virus in a 5-Year Prospective Cohort Study in Thailand

2019 ◽  
Vol 10 ◽  
Author(s):  
Luis A. Sánchez-Vargas ◽  
Sonia Kounlavouth ◽  
Madison L. Smith ◽  
Kathryn B. Anderson ◽  
Anon Srikiatkhachorn ◽  
...  
Keyword(s):  
Cohort Study ◽  
T Cell ◽  
Dengue Virus ◽  
Prospective Cohort Study ◽  
Longitudinal Analysis ◽  
Prospective Cohort ◽  
T Cell Responses ◽  
Cell Responses

scholarly journals Increased Loss of CCR5+ CD45RA− CD4+ T Cells in CD8+ Lymphocyte-Depleted Simian Immunodeficiency Virus-Infected Rhesus Monkeys

2008 ◽  
Vol 82 (11) ◽  
pp. 5618-5630 ◽  
Author(s):  
Ronald S. Veazey ◽  
Paula M. Acierno ◽  
Kimberly J. McEvers ◽  
Susanne H. C. Baumeister ◽  
Gabriel J. Foster ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Simian Immunodeficiency Virus ◽  
Peripheral Blood ◽  
T Cell Responses ◽  
Lymphocyte Depletion ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Siv Infection

ABSTRACT Previously we have shown that CD8+ T cells are critical for containment of simian immunodeficiency virus (SIV) viremia and that rapid and profound depletion of CD4+ T cells occurs in the intestinal tract of acutely infected macaques. To determine the impact of SIV-specific CD8+ T-cell responses on the magnitude of the CD4+ T-cell depletion, we investigated the effect of CD8+ lymphocyte depletion during primary SIV infection on CD4+ T-cell subsets and function in peripheral blood, lymph nodes, and intestinal tissues. In peripheral blood, CD8+ lymphocyte-depletion changed the dynamics of CD4+ T-cell loss, resulting in a more pronounced loss 2 weeks after infection, followed by a temporal rebound approximately 2 months after infection, when absolute numbers of CD4+ T cells were restored to baseline levels. These CD4+ T cells showed a markedly skewed phenotype, however, as there were decreased levels of memory cells in CD8+ lymphocyte-depleted macaques compared to controls. In intestinal tissues and lymph nodes, we observed a significantly higher loss of CCR5+ CD45RA− CD4+ T cells in CD8+ lymphocyte-depleted macaques than in controls, suggesting that these SIV-targeted CD4+ T cells were eliminated more efficiently in CD8+ lymphocyte-depleted animals. Also, CD8+ lymphocyte depletion significantly affected the ability to generate SIV Gag-specific CD4+ T-cell responses and neutralizing antibodies. These results reemphasize that SIV-specific CD8+ T-cell responses are absolutely critical to initiate at least partial control of SIV infection.

scholarly journals The T-Cell Receptor Repertoire Predicts Interim-PET in Patients with DLBCL Treated with R-CHOP: An Observational Study from a Prospective Clinical Trial

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 825-825
Author(s):  
Mohamed Shanavas ◽  
Mark Hertzberg ◽  
Rodney J Hicks ◽  
John F Seymour ◽  
Joshua W.D. Tobin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Peripheral Blood ◽  
T Cell Responses ◽  
Cell Receptor ◽  
Variable Degree ◽  
Cell Responses ◽  
Interim Pet ◽  
Tcr Repertoire

Abstract T-cell infiltration of the tumor microenvironment (TME) in DLBCL is a key determinant of response to chemo-immunotherapy (Keane, Lancet Haem 2015). We have previously shown that greater diversity of the T-cell receptor (TCR) repertoire within the TME is correlated with improved survival following R-CHOP in DLBCL (Keane, CCR 2017). There are limited data on the impact of the intratumoral TCR repertoire on interim-PET (iPET), the relationship between intratumoral and circulating TCRs, and on dynamic changes of the TCR during therapy. In this study, we interrogated the TCR repertoire in a subset of DLBCL patients treated on the prospective Australasian Leukaemia Lymphoma Group NHL21 study (Hertzberg, Haematologica 2017), in which all patients had 4x RCHOP prior to iPET risk stratification. The CDR3 region of TCRβ chain underwent high-throughput unbiased TCRβ sequencing (Adaptive Biotechnologies). Metrics included: productive templates (total functional T-cells), productive rearrangements (functional T-cells with distinct specificity), productive clonality (repertoire unevenness due to clonal expansions), and maximal frequency clones (% most dominant single clone). Matched intratumoral diagnostic samples, blood at pre-therapy and post-cycle 4 (at the time of iPET) were tested. 42 patients (enriched for iPET+ cases) had sufficient material for testing. Median age was 55 (range 22-69) years and 72% were males. IPI was low/intermediate/high in 13/63/25% respectively. Cell of origin (COO) by Lymph 2CX method (nanoString) was ABC in 30%, and GCB in 44%. 40% were iPET+. In tissue, there was a median of 4652 productive templates, translating into 2998 productive rearrangements identified. Notably, the clonal repertoire of intratumoral TCRs in iPET+ patients was larger than iPET-ve patients (productive clonality 8.1 vs 5.1 x10-2, p=0.04), whereas the numbers of functional T-cells did not vary between groups. Comparing the tumor with the blood samples showed a high, but variable, degree of overlap between peripheral blood and the TME - TCR repertoire. Median number of top 100 tumor tissue clones shared in peripheral blood was 53.5 (range, 1-97) in pre-therapy and 39.5 (range, 0-93) in post-therapy blood, indicating that the both the circulation and the tumor likely contribute to immune-surveillance. In pre-therapy blood, the median productive templates and productive rearrangements were 44,950 (range, 6,003-273,765) and 29,090 (range, 5,190-152,706), and the median clonality was 8.5 (1.46-45.3) x 10-2. There were no differences between iPET+ and iPET-ve patients in these parameters. However, there was a marked change in T-cell composition between time points. Interestingly, in iPET-ve patients clonality measures were increased, with productive clonality 9.4 vs 14.4 x10-2, p=0.03; and % maximum productive frequency 3.39 vs 5.89, p=0.04. These findings demonstrate that the intratumoral TCR repertoire, and sequential blood sampling provide important information on outcome in DLBCL treated with RCHOP. A highly clonal T-cell repertoire in the TME was associated with iPET positivity after 4 cycles of R-CHOP. In line with findings in solid cancers treated with checkpoint blockade, development of clonal responses in peripheral blood was associated with iPET negativity. These findings indicate that clones expanded during therapy may be important in tumor clearance but that highly clonal T-cell responses in the tumor at diagnosis may hinder expansion of other T-cell responses to neoantigens. The circulating TCR composition is representative of the TME. These findings will assist the rationale design and therapeutic monitoring of novel immuno-therapeutic strategies. Disclosures No relevant conflicts of interest to declare.

scholarly journals Exploring T Cell Reactivity to Gliadin in Young Children with Newly Diagnosed Celiac Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Edwin Liu ◽  
Kristen McDaniel ◽  
Stephanie Case ◽  
Liping Yu ◽  
Bernd Gerhartz ◽  
...  
Keyword(s):  
T Cells ◽  
Celiac Disease ◽  
T Cell ◽  
Young Children ◽  
Peripheral Blood ◽  
T Cell Responses ◽  
Cd4 T Cell ◽  
Newly Diagnosed ◽  
Cell Responses ◽  
Gliadin Peptides

Class II major histocompatibility molecules confer disease risk in Celiac disease (CD) by presenting gliadin peptides to CD4 T cells in the small intestine. Deamidation of gliadin peptides by tissue transglutaminase creates immunogenic peptides presented by HLA-DQ2 and DQ8 molecules to activate proinflammatory CD4 T cells. Detecting gliadin specific T cell responses from the peripheral blood has been challenging due to low circulating frequencies and heterogeneity in response to gliadin epitopes. We investigated the peripheral T cell responses to alpha and gamma gliadin epitopes in young children with newly diagnosed and untreated CD. Using peptide/MHC recombinant protein constructs, we are able to robustly stimulate CD4 T cell clones previously derived from intestinal biopsies of CD patients. These recombinant proteins and a panel ofα- andγ-gliadin peptides were used to assess T cell responses from the peripheral blood. Proliferation assays using peripheral blood mononuclear cells revealed more CD4 T cell responses toα-gliadin thanγ-gliadin peptides with a single deamidatedα-gliadin peptide able to identify 60% of CD children. We conclude that it is possible to detect T cell responses without a gluten challenge or in vitro stimulus other than antigen, when measuring proliferative responses.

Induction of Potentially Protective HIV-Specific T-Cell Responses In Vitro by Gag mRNA-Electroporated Dendritic Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1261-1261
Author(s):  
Zwi N. Berneman ◽  
Ellen R. Van Gulck ◽  
Leo Heyndrickx ◽  
Peter Ponsaerts ◽  
Viggo F.I. Van Tendeloo ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cell Count ◽  
Cd8 T Cells ◽  
Peripheral Blood ◽  
T Cell Responses ◽  
Ifn Gamma ◽  
Cell Responses ◽  
Hiv 1

Abstract Human immunodeficiency virus type 1 (HIV-1) infection is characterized by dysfunction of HIV-1-specific T-lymphocytes. In order to suppress the virus and delay evolution to AIDS, antigen-loaded antigen-presenting cells, including dendritic cells (DC) might be useful to boost and broaden HIV-1-specific T-cell responses. Monocyte-derived DC from 15 untreated (“naive”) and 15 highly active anti-retroviral therapy (HAART)-treated HIV-1-infected patients were electroporated with codon-optimized (“humanized”) mRNA encoding consensus HxB-2 (hHxB-2) Gag protein. These DC were co-cultured for 1 week with autologous peripheral blood leucocytes (PBL). Potential expansion of specific T-cells was measured by comparing ELISPOT responses of PBL before and after co-culture, using a pool of overlapping peptides, spanning the HxB-2 Gag. Expansion of specific PBL after co-culture was noted for T cells producing interferon (IFN)-gamma, interleukin (IL)-2 and perforin (Wilcoxon signed rank test p<0.05, except for IL-2 in naive patients). From all HIV-1-seropositive persons tested, 12 HAART-treated and 12 naive patients match in absolute number of CD4+ T-cells. A comparison of the increase of the response between day 0 and after 1 week of stimulation between those two groups showed that the response was higher in HAART-treated subjects for IFN-gamma and IL-2 but not for perforin in comparison to untreated subjects. Examining purified CD4+ and CD8+ T-cells after co-culture revealed that HxB-2 Gag peptides induced IFN-gamma in both subsets, that IL-2 was only secreted by CD4+ T-cells and that perforin was dominantly secreted by CD8+ T-cells. Remarkably, the perforin response in the treatment-naive persons was negatively correlated with the peripheral blood absolute CD4+ and CD8+ T-cell count (respectively R=0.618, p=0.014; and R=0.529, p=0.043). Furthermore, the nadir absolute CD4+ T-cell count in HAART-treated subjects was positively correlated with the IL-2 response (R=0.521, p=0.046) and negatively correlated with the perforin response (R=0.588, p=0.021). In conclusion, DC from HAART-treated and therapy-naive subjects, electroporated with hHxB-2 gag mRNA have the capacity to induce secondary T-cell responses. In an earlier study (Van Gulck ER et al. Blood2006;107:1818–1827), we already demonstrated ex vivo that CD4+ and CD8+ T-cells from non-treated HIV-1-infected subjects can be directly triggered by DC electroporated with autologous proviral-derived gag mRNA. Taken together, our results open the perspective for a DC immunotherapy for HIV disease.

scholarly journals Antiviral Therapy during Primary Simian Immunodeficiency Virus Infection Fails To Prevent Acute Loss of CD4+ T Cells in Gut Mucosa but Enhances Their Rapid Restoration through Central Memory T Cells

2008 ◽  
Vol 82 (8) ◽  
pp. 4016-4027 ◽  
Author(s):  
David Verhoeven ◽  
Sumathi Sankaran ◽  
Melanie Silvey ◽  
Satya Dandekar
Keyword(s):  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Peripheral Blood ◽  
Viral Suppression ◽  
T Cell Responses ◽  
Cell Loss ◽  
Central Memory ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT Gut-associated lymphoid tissue (GALT) is an early target of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) and a site for severe CD4+ T-cell depletion. Although antiretroviral therapy (ART) is effective in suppressing HIV replication and restoring CD4+ T cells in peripheral blood, restoration in GALT is delayed. The role of restored CD4+ T-cell help in GALT during ART and its impact on antiviral CD8+ T-cell responses have not been investigated. Using the SIV model, we investigated gut CD4+ T-cell restoration in infected macaques, initiating ART during either the primary stage (1 week postinfection), prior to acute CD4+ cell loss (PSI), or during the chronic stage at 10 weeks postinfection (CSI). ART led to viral suppression in GALT and peripheral blood mononuclear cells of PSI and CSI animals at comparable levels. CSI animals had incomplete CD4+ T-cell restoration in GALT. In PSI animals, ART did not prevent acute CD4+ T-cell loss by 2 weeks postinfection in GALT but supported rapid and complete CD4+ T-cell restoration thereafter. This correlated with an accumulation of central memory CD4+ T cells and better suppression of inflammation. Restoration of CD4+ T cells in GALT correlated with qualitative changes in SIV gag-specific CD8+ T-cell responses, with a dominance of interleukin-2-producing responses in PSI animals, while both CSI macaques and untreated SIV-infected controls were dominated by gamma interferon responses. Thus, central memory CD4+ T-cell levels and qualitative antiviral CD8+ T-cell responses, independent of viral suppression, were the immune correlates of gut mucosal immune restoration during ART.

Ex Vivo Modulation of Donor Cells Results in Enhanced Survival and Reduced Gvhd Mortality

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1884-1884 ◽  
Author(s):  
Lisa Guerrettaz ◽  
Newsha Sahaf ◽  
Leah Mitchell ◽  
Chris Lynn ◽  
Sarah Raynel ◽  
...  
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
Immune Tolerance ◽  
Peripheral Blood ◽  
Ex Vivo ◽  
T Cell Responses ◽  
Cell Transplant ◽  
Cell Responses ◽  
Mobilized Peripheral Blood

Abstract Allogeneic hematopoietic stem cell transplant (HSCT) represents a potential curative treatment for a number of life-threatening blood malignancies. The utility of this treatment regimen, however, is limited by a number of serious complications including graft versus host disease, which occurs in approximately half of all transplant patients. Standard-of-care for treating acute GvHD has remained unchanged for several decades and consists of high doses of steroids, which are only effective in approximately 35 percent of the cases. Therefore, the reduction of GvHD represents a large unmet medical need, and new approaches are needed to effectively attenuate GvHD. Here we present a fundamentally novel strategy for potentially reducing GVHD - by modulating donor mobilized peripheral blood cells with small molecules prior to HSCT, a programmed mobilized peripheral blood (mPB) allogeneic graft, with reduced T-cell alloreactivity, can be administered as the hematopoietic cell source for HSCT. To this end, we applied our screening platform to identify a combination of small molecule modulators (FT1050, FT4145) that promote the activation of genes implicated in cell cycle, immune tolerance and anti-viral properties of T cells, as well as in the survival, proliferation and engraftment potential of CD34+ cells. Genome-wide expression analysis of the T-cell compartment of mobilized peripheral blood following treatment with FT1050+FT4145 revealed the induction of genes involved in cell cycle (e.g., CCND1, CCNE1), immune tolerance (e.g., ALDH, AREG) and anti-viral properties (e.g., EFNB2). To further assess the therapeutic impact of ex vivo programming with FT1050 and FT4145, a number of T cell assays to assess T cell phenotype and function were conducted on mPB. Overall, ex vivo programming of mPB resulted in reduced allogeneic T cell responses and was accompanied by reduced capacity of modulated T cells to produce Interferon Gamma (IFN-ɣ). Concomitantly, the ability of the modulated T cells to make Interleukin 4 (IL-4) and 10 (IL-10) was enhanced, suggesting a polarization of these cells towards a less inflammatory functional state. This was further evidenced by increased surface expression of an immune-inhibitory molecule, PD1, and reduced expression of the activation markers 41BB and ICOS. We next examined the potential beneficial role of ex vivo programming with FT1050+FT4145 in a major histocompatibility complex (MHC) mis-matched HSCT mouse model. Briefly, lethally irradiated BALB/c mice received bone marrow and splenocytes from C57BL/6 donor mice pulse treated with vehicle or FT1050+FT4145. Significantly less GvHD, as determined by survival, weight loss, GVHD score (diarrhea, inactivity, hunched posture, ruffled fur, eye lesion, snout swelling/skin integrity), cytokine production and histopathology of GvHD target organs was observed in recipients receiving FT1050+FT4145 treated cells as compared to those receiving vehicle treated cells. In addition, we observed increased levels of donor T regulatory cells (Tregs) in secondary lymphoid organs concomitant with decreased levels of circulating IFN-ɣ in recipients receiving FT1050+FT4145 treated cells. Based on the attenuation of alloreactive T-cell responses in these preclinical studies, we believe our findings provide a compelling scientific basis to support the clinical evaluation of ex vivo programmed mobilized peripheral blood in patients undergoing HSCT for the treatment of hematologic malignancies. Disclosures Levin: Fate Therapeutics, Inc: Employment, Equity Ownership. Shoemaker:Fate Therapeutics Inc: Employment.

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