Cross-recognition of HLA DR4 alloantigen by virus-specific CD8+ T cells: a new paradigm for self-/nonself-recognition

Blood ◽  
2009 ◽  
Vol 114 (11) ◽  
pp. 2244-2253 ◽  
Author(s):  
Michael Rist ◽  
Corey Smith ◽  
Melissa J. Bell ◽  
Scott R. Burrows ◽  
Rajiv Khanna
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cd8 T Cells ◽  
Allograft Rejection ◽  
Functional Characterization ◽  
Cell Receptor ◽  
T Cell Response ◽  
Cell Repertoire ◽  
Diverse Range

Abstract The ability of CD8+ T cells to engage a diverse range of peptide–major histocompatibility complex (MHC) complexes can also lead to cross-recognition of self and nonself peptide-MHC complexes and thus directly contribute toward allograft rejection or autoimmunity. Here we present a novel form of cross-recognition by herpes virus–specific CD8+ cytotoxic T cells that challenges the current paradigm of self/non-self recognition. Functional characterization of a human leukocyte antigen (HLA) Cw*0602-restricted cytomegalovirus-specific CD8+ T-cell response revealed an unusual dual specificity toward a pp65 epitope and the alloantigen HLA DR4. This cross-recognition of HLA DR4 alloantigen was critically dependent on the coexpression of HLA DM and was preferentially directed toward the B-cell lineage. Furthermore, allostimulation of peripheral blood lymphocytes with HLA DRB*0401-expressing cells rapidly expanded CD8+ T cells, which recognized the pp65 epitope in the context of HLA Cw*0602. T-cell repertoire analysis revealed 2 dominant populations expressing T-cell receptor beta variable (TRBV)4-3 or TRBV13, with cross-reactivity exclusively mediated by the TRBV13+ clonotypes. More importantly, cross-reactive TRBV13+ clonotypes displayed markedly lower T-cell receptor binding affinity and a distinct pattern of peptide recognition, presumably mimicking a structure presented on the HLA DR4 allotype. These results illustrate a novel mechanism whereby virus-specific CD8+ T cells can cross-recognize HLA class II molecules and may contribute toward allograft rejection and/or autoimmunity.

Evolution of the Donor T Cell Repertoire In Allogeneic Stem Cell Transplant Recipients In the Second Decade After Transplantation

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 831-831
Author(s):  
Robert Q. Le ◽  
J. Joseph Melenhorst ◽  
Brenna Hill ◽  
Sarfraz Memon ◽  
Minoo Battiwalla ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
T Cell Receptor ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Cell Receptor ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Significant Difference

Abstract Abstract 831 After allogeneic stem cell transplantation (SCT), donor T lymphocyte immune function is slowly re-established in the recipient through reconstruction of the donor's post-thymic T cell repertoire and from T cell neogenesis in the thymus. Although long-term survivors from SCT appear healthy, their immune repertoire and differences from that of their donors have not been characterized. We studied 38 healthy patients surviving more than 10 years from a myeloablative SCT for hematological malignancy (median follow-up 12 years, range 10–16 years). T cell and natural killer (NK) cell repertoires in these patients were compared with cells from their stem cell donors cryopreserved at time of transplant and from the same donors at 10 year after SCT. The median age of both recipients and their sibling donors at time of transplant was identical (36 years). Patients received cyclosporine GVHD prophylaxis and delayed add-back of donor lymphocytes 30–90 days post transplant. Only one patient was on continued immunosuppressive treatment at the time of study. Compared with the donor pre-transplant counts there was no significant difference in the absolute lymphocyte, neutrophil, monocyte, CD4+ and CD8+ T cell, NK cell, and B cell subset counts. However, compared to their donors, recipients had a) significantly fewer naïve CD4+ and CD8+ T cells; b) lower T cell receptor excision circles levels; c) fewer CD4+ central memory T cells; d) more effector CD8+ T cells; e) and more FOXP3+ regulatory T cells. These data suggest that the patient had a persistent deficiency on T cell neogenesis. Molecular examination of the T cell receptor Vbeta (TCRBV) repertoire by spectratype analysis showed that there was no significant difference in total complexity score, defined as the sum of the number of discrete peaks for each Vbeta subfamily, between the patients and their donors. TCRBV subfamily spectratyping profiles of patients and donors, however, had diverged, with both gains and losses of peaks identifiable in both patient and donor. In conclusion, patients surviving 10 or more years after allogeneic SCT still show a T cell repertoire that reflects expansion of the donor-derived post thymic T cell compartment, with a limited contribution by new T cell generation and persistently increased Tregs. It therefore appears that a diverse TCRBV repertoire predominantly derived from the memory T cell pool is compatible with good health. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Unresponsiveness to a self-peptide of mouse lysozyme owing to hindrance of T cell receptor-major histocompatibility complex/peptide interaction caused by flanking epitopic residues.

1996 ◽  
Vol 183 (2) ◽  
pp. 535-546 ◽  
Author(s):  
K D Moudgil ◽  
I S Grewal ◽  
P E Jensen ◽  
E E Sercarz
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Response ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Histocompatibility Complex ◽  
Critical Residues ◽  
Mouse Lysozyme

A self-peptide containing amino acid residues 46-61 (NRGDQSTDYGIFQINSR) of mouse lysozyme (ML) (p46-61, which binds strongly to the A(k) molecule but does not bind to the E(k) molecule), can induce a strong proliferative T cell response in CBA/J mice (A[k], E[k]) but no response at all in B10.A(4R) and CBA/J mice. The critical residues within p46-59 are immunogenic in both B10.A(4R) and CBA/J mice. The critical residues within p46-61 reside between amino acid positions 51 and 59. T cells of B10.A(4R) mice primed with the truncated peptides in vivo cannot be restimulated by p46-61 in vitro. This suggests that T cell receptor (TCR) contact (epitopic) residue(s) flanking the minimal 51-59 determinant within p46-61 hinder the interaction of the p46-61/A(k) complex with the appropriate TCR(S), thereby causing a lack of proliferative T cell response in this mouse strain. Unlike B10.A(4R) mice, [B10.A(4R) x CBA/J]F1 mice responded vigorously to p46-61, suggesting that thymic APC of B10.A(4R) mice do not present a self ligand to T cells resulting in a p46-61-specific hole in the T cell repertoire in B10.A(4R) or the F1 mice. Moreover, APC from B10.A(4R) mice are capable of efficiently presenting p46-61 to peptide-specific T cell lines from CBA/J mice. The proliferative unresponsiveness of B10.A(4R) mice to p46-61 is not due to non-major histocompatibility complex genes because B10.A mice (A[k], E[k]) respond well to p46-61. Interestingly, B10.A(4R) mice can raise a good proliferative response to p46-61 (R61A) (in which the arginine residue at position 61 (R61L/F/N/K), indicating that R61 was indeed responsible for hindering the interaction of p46-61 with the appropriate TCR. Finally, chimeric mice [B10.A(4R)-->B10.A] responded vigorously to p46-61, suggesting that thymic antigen presentation environment of the B10.A mouse was critical for development of a p46-61-reactive T cell repertoire. Thus, we provide experimental demonstration of a novel mechanism for unresponsiveness to a self peptide, p46-61, in the B10.A(4R) mouse owing to hindrance: in this system it is the interaction between the available TCR and the A(k)/p46-61 complex, which is hindered by epitopic residue(s) within p46-61. We argue that besides possessing T cells that are hindered by R61 of p46-61, CBA/J and B10.A mice have developed an additional subset of T cells bearing TCRs which are not hinderable by R61, presumably through positive selection with peptides derived from class II E(k), or class I D(k)/D(d) molecules. These results have important implications in self tolerance, shaping of the T cell repertoire, and in defining susceptibility to autoimmunity.

Functional and Numerical T Cell Abnormalities in Chronic Lymphocytic Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3085-3085
Author(s):  
Mark C. Lanasa ◽  
Marc C. Levesque ◽  
Sallie D. Allgood ◽  
Jon P. Gockerman ◽  
Karen Bond ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cell Receptor ◽  
T Cell Subsets ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Unequal Variances

Abstract Background: Although most malignancies are associated with decreased numbers of circulating T cells, in CLL they are elevated 2 to 4 times normal. Rather than promoting an anti-tumor response, this increased population of T cells may contribute to a tumor microenvironment that fosters progression of the malignant clone. Immunocompetent individuals show a wide repertoire of antigen specificity in both CD4+ and CD8+ T cells, but the T cell repertoire is significantly restricted in CLL. This restriction of the T cell repertoire may be an important cause of infectious morbidity in patients with CLL. To better understand these T cell abnormalities, we enumerated T cell subsets and determined T cell receptor diversity in 18 untreated patients with CLL. Methods: T cell subsets were enumerated from peripheral blood using highly sensitive 6-color flow cytometry. The T cell repertoire was determined for 23 T cell receptor variable β chain families (TCRvβ) in purified CD4+ and CD8+ T cells. These T cell subsets were considered separately because differential restriction of the CD4+ and CD8+ subsets has been reported previously. A PCR-based spectratype assay was used to analyze the length distribution of the TCR complementarity-determining region 3 (CDR3). A limitation of prior reports using spectratype assays was that adequately complex statistical models did not exist to simultaneously analyze the highly diverse vβ families. We addressed this limitation by using a recently-developed statistical method for spectratype analysis (Bioinformatics. 21:3394–400). Briefly, for each vβ family, the divergence from an expected reference distribution was calculated. A divergence coefficient was determined for each vβ family, and the mean divergence of all 23 vβ families was calculated. This allowed for statistical comparisons among individual patients and specific vβ families. To our knowledge, we are the first group to apply this powerful methodology to the analysis of T cell repertoires in patients with CLL. Results: We found both the CD4+ and CD8+ subsets to be expanded (mean #/μL ± SD: 1134 ± 646 and 768 ± 716, respectively; reference normal CD4+ range 401–1532, CD8+ 152–838). The absolute number of CD4+ and CD8+ T cells was greater in patients with higher absolute CLL lymphocyte counts (p = 0.018, r2 = 0.30, and p = 0.23, r2 = 0.09, respectively, linear regression). The CD4:CD8 ratio was lower in IgVH unmutated subjects (mutated 2.6, umutated 1.7, p = 0.09, two-tailed t-test assuming unequal variances). Though prior reports have disagreed on whether CD4+ or CD8+ subsets show greater restriction of clonality, we observed striking clonal restriction of CD8+ but not CD4+ T cells (p < 1×10−7, 2 sided t-test assuming unequal variances). There was a trend toward greater restriction of the CD8+ subset among patients with IgVH unmutated and Zap70+ CLL, but there was no correlation with lymphocyte doubling time. Conclusions: In this cohort of 18 untreated patients with CLL, there was a greater proportional increase compared to reference standards of CD8+ versus CD4+ T cells. However, the increase in CD4+, but not CD8+, T cell numbers was significantly correlated to total CLL lymphocyte count. This observation suggests that expansion of the CD4+ T cell pool observed in CLL is proportional to leukemic burden. The restriction of TCRvβ was limited to CD8+ T cells and that this effect was independent of the size of the abnormal clone. Taken together, these findings suggest different mechanisms of dysregulation of CD4+ and CD8+ T cell subsets in CLL.

scholarly journals In chronic infection, HIV gag-specific CD4+ T cell receptor diversity is higher than CD8+ T cell receptor diversity and is associated with less HIV quasispecies diversity

2021 ◽  
Author(s):  
Mark A Pilkinton ◽  
Wyatt J McDonnell ◽  
Louise Barnett ◽  
Abha Chopra ◽  
Rama Gangula ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cell Receptor ◽  
T Cell Response ◽  
Cd4 T Cell ◽  
Tcr Repertoire ◽  
Tcr Diversity

Cellular immune responses to Gag correlate with improved HIV viral control. The full extent of cellular immune responses comprise both the number of epitopes recognized by CD4+ and CD8+ T cells, as well as the diversity of the T cell receptor (TCR) repertoire directed against each epitope. The optimal diversity of the responsive TCR repertoire is unclear. Therefore, we evaluated the TCR diversity of CD4+ and CD8+ T cells responding to HIV-1 Gag to determine if TCR diversity correlates with clinical or virologic metrics. Previous studies of TCR repertoires have been limited primarily to CD8+ T cell responses directed against a small number of well-characterized T cell epitopes restricted by specific human leucocyte antigens. We stimulated peripheral blood mononuclear cells from 21chronic HIV-infected individuals overnight with a pool of HIV-1 Gag peptides, followed by sorting of activated CD4+ and CD8+ T cells and TCR deep sequencing. We found Gag-reactive CD8+ T cells to be more oligoclonal, with a few dominant TCRs comprising the bulk of the repertoire, compared to the highly diverse TCR repertoires of Gag-reactive CD4+ T cells. HIV viral sequencing of the same donors revealed that high CD4+ T cell TCR diversity was strongly associated with lower HIV Gag genetic diversity. We conclude that the TCR repertoire of Gag-reactive CD4+ T helper cells display substantial diversity without a clearly dominant circulating TCR clonotype, in contrast to a hierarchy of dominant TCR clonotypes in the Gag-reactive CD8+ T cells, and may serve to limit HIV diversity during chronic infection. IMPORTANCE Human T cells recognize portions of viral proteins bound to host molecules (human leucocyte antigens) on the surface of infected cells. T cells recognize these foreign proteins through their T cell receptors (TCRs), which are formed by the assortment of several available V, D and J genes to create millions of combinations of unique TCRs. We measured the diversity of T cells responding to the HIV Gag protein. We found the CD8+ T cell response is primarily made up of a few dominant unique TCRs whereas the CD4+ T cell subset has a much more diverse repertoire of TCRs. We also found there was less change in the virus sequences in subjects with more diverse TCR repertoires. HIV has a high mutation rate, which allows it to evade the immune response. Our findings describe the characteristics of a virus-specific T cell response that may allow it to limit viral evolution.

scholarly journals Control of HIV-1 immune escape by CD8 T cells expressing enhanced T-cell receptor

2008 ◽  
Vol 14 (12) ◽  
pp. 1390-1395 ◽  
Author(s):  
Angel Varela-Rohena ◽  
Peter E Molloy ◽  
Steven M Dunn ◽  
Yi Li ◽  
Megan M Suhoski ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cd8 T Cells ◽  
Immune Escape ◽  
Cell Receptor ◽  
Hiv 1

scholarly journals Characterization of Changes in the T-Cell Receptor Repertoire in Patients with Acute Myeloid Leukemia with Durable Remission Following Allogeneic Stem Cell Transplant

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5186-5186
Author(s):  
Ronald M. Paranal ◽  
Hagop M. Kantarjian ◽  
Alexandre Reuben ◽  
Celine Kerros ◽  
Priya Koppikar ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Cell Receptor ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Donor T Cells ◽  
Durable Remission

Introduction: Allogeneic hematopoietic stem-cell transplantation (HSCT) is curative for many patients with advanced hematologic cancers, including adverse-risk acute myeloid leukemia (AML). This is principally through the induction of a graft-versus-leukemia (GVL) immune effect, mediated by donor T-cells. The incredible diversity and specificity of T-cells is due to rearrangement between V, D, and J regions and the random insertion/deletion of nucleotides, taking place in the hypervariable complementarity determining region 3 (CD3) of the T-cell receptor (TCR). Massively parallel sequencing of CDR3 allows for a detailed understanding of the T-cell repertoire, an area relatively unexplored in AML. Therefore, we sought out to characterize the T-cell repertoire in AML before and after HSCT, specifically for those with a durable remission. Methods: We identified 45 bone marrow biopsy samples, paired pre- and post-HSCT, from 14 patients with AML in remission for > 2 years as of last follow-up. We next performed immunosequencing of the TCRβ repertoire (Adaptive Biotechnologies). DNA was amplified in a bias-controlled multiplex PCR, resulting in amplification of rearranged VDJ segments, followed by high-throughput sequencing. Resultant sequences were collapsed and filtered in order to identify and quantitate the absolute abundance of each unique TCRβ CDR3 region. We next employed various metrics to characterize changes in the TCR repertoire: (1) clonality (range: 0-1; values closer to 1 indicate a more oligoclonal repertoire), it accounts for both the number of unique clonotypes and the extent to which a few clonotypes dominate the repertoire; (2) richness with a higher number indicating a more diverse repertoire with more unique rearrangements); (3) overlap (range: 0-1; with 1 being an identical T-cell repertoire). All calculations were done using the ImmunoSeq Analyzer software. Results: The median age of patients included in this cohort was 58 years (range: 31-69). Six patient (43%) had a matched related donor, and 8 (57%) had a matched unrelated donor. Baseline characteristics are summarized in Figure 1A. Six samples were excluded from further analysis due to quality. TCR richness did not differ comparing pre- and post-HSCT, with a median number pre-HSCT of 3566 unique sequences (range: 1282-22509) vs 3720 (range: 1540-12879) post-HSCT (P = 0.7). In order to assess whether there was expansion of certain T-cell clones following HSCT, we employed several metrics and all were indicative of an increase in clonality (Figure 2B). Productive clonality, a measure of reactivity, was significantly higher in post-transplant samples (0.09 vs 0.02, P = 0.003). This is a measure that would predict expansion of sequences likely to produce functional TCRs. The Maximum Productive Frequency Index was higher post-HSCT indicating that the increase in clonality was driven by the top clone (most prevalent per sample). Similarly for the Simpson's Dominance index, another marker of clonality which was higher post-HSCT (0.01 vs 0.0009, P = 0.04). In order to determine whether this clonal expansion was driven by TCR clones shared among patients, we compared the degree of overlap in unique sequences among pre and post-HSCT samples. We found there was very little overlap between samples in the pre and the post-transplant setting and no change in the Morisita and Jaccard Overlap Indices. Conclusions: In conclusion, we show in this analysis an increase in clonality of T-cells following HSCT in patients with AML. This is likely related to the GVL effect after recognition of leukemia antigens by donor T cells and subsequent expansion of these T-cells. These expanded T-cell clonotypes were unlikely to be shared by patients in this cohort, likely reflecting the variety of antigens leading to the GVL effect. This could have direct implications on TCR-mediated immune-therapies given the likely need for a personalized, patient-specific design for these therapies. Figure 1 Disclosures Kantarjian: BMS: Research Funding; Novartis: Research Funding; AbbVie: Honoraria, Research Funding; Jazz Pharma: Research Funding; Astex: Research Funding; Immunogen: Research Funding; Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Agios: Honoraria, Research Funding; Daiichi-Sankyo: Research Funding; Takeda: Honoraria; Amgen: Honoraria, Research Funding; Cyclacel: Research Funding; Ariad: Research Funding; Pfizer: Honoraria, Research Funding. Short:Takeda Oncology: Consultancy, Research Funding; AstraZeneca: Consultancy; Amgen: Honoraria. Cortes:Takeda: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding; Sun Pharma: Research Funding; BiolineRx: Consultancy; Novartis: Consultancy, Honoraria, Research Funding; Astellas Pharma: Consultancy, Honoraria, Research Funding; Merus: Consultancy, Honoraria, Research Funding; Immunogen: Consultancy, Honoraria, Research Funding; Biopath Holdings: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Forma Therapeutics: Consultancy, Honoraria, Research Funding. Jabbour:Cyclacel LTD: Research Funding; Pfizer: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding. Molldrem:M. D. Anderson & Astellas Pharma: Other: Royalties.

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