scholarly journals Engrafted maternal T cells in a severe combined immunodeficiency patient express T-cell receptor variable beta segments characterized by a restricted V-D-J junctional diversity

Blood ◽  
1995 ◽  
Vol 85 (8) ◽  
pp. 2105-2113 ◽  
Author(s):  
A Sottini ◽  
E Quiros-Roldan ◽  
LD Notarangelo ◽  
A Malagoli ◽  
D Primi ◽  
...  

To better understand the peculiar functional behavior of engrafted maternal T cells in a severe combined immunodeficiency (SCID) patient, we characterized, at the molecular level, the T-cell repertoire of a SCID child with a high number of engrafted, mature, activated lymphocytes. We found that, although these transplacentally acquired T cells express a random set of T-cell receptor variable beta (TCRBV) segments, the TCRBV transcripts are characterized by an extremely restricted V-D-J junctional diversity. Only a few cDNA clones were dominant among the TCRBV4+, TCRBV6+, and TCRBV20+ populations in engrafted cells, whereas the same TCRBV chains expressed by the mother's lymphocytes had the expected junctional hetero-geneity. Highly diverse and polyclonal junctions were also expressed by maternal cells activated in mixed lymphocyte reaction by Epstein-Barr virus (EBV)- transformed B lymphocytes from the patient, indicating that the strong clonal selection that characterizes the engrafted cells repertoire is probably not due to allorecognition. Furthermore, we report that the repertoire of the transplacentally acquired lymphocytes is dynamic over time and is characterized by waves of expression and contraction of selected clones, expressing different TCRBV segments. These results help to explain some of the abnormal functional behaviors of engrafted maternal cells and raise new questions regarding the mechanisms responsible for the restricted clonal diversity.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5186-5186
Author(s):  
Ronald M. Paranal ◽  
Hagop M. Kantarjian ◽  
Alexandre Reuben ◽  
Celine Kerros ◽  
Priya Koppikar ◽  
...  

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.


Blood ◽  
2008 ◽  
Vol 111 (4) ◽  
pp. 2053-2061 ◽  
Author(s):  
Laura Crompton ◽  
Naeem Khan ◽  
Rajiv Khanna ◽  
Laxman Nayak ◽  
Paul A. H. Moss

Antigen-specific CD8+ cytotoxic T cells often demonstrate extreme conservation of T-cell receptor (TCR) usage between different individuals, but similar characteristics have not been documented for CD4+ T cells. CD4+ T cells predominantly have a helper immune role, but a cytotoxic CD4+ T-cell subset has been characterized, and we have studied the cytotoxic CD4+ T-cell response to a peptide from human cytomegalovirus glycoprotein B presented through HLA-DRB*0701. We show that this peptide elicits a cytotoxic CD4+ T-cell response that averages 3.6% of the total CD4+ T-cell repertoire of cytomegalovirus-seropositive donors. Moreover, CD4+ cytotoxic T-cell clones isolated from different individuals exhibit extensive conservation of TCR usage, which indicates strong T-cell clonal selection for peptide recognition. Remarkably, this TCR sequence was recently reported in more than 50% of cases of CD4+ T-cell large granular lymphocytosis. Immunodominance of cytotoxic CD4+ T cells thus parallels that of CD8+ subsets and suggests that cytotoxic effector function is critical to the development of T-cell clonal selection, possibly from immune competition secondary to lysis of antigen-presenting cells. In addition, these TCR sequences are highly homologous to those observed in HLA-DR7+ patients with CD4+ T-cell large granular lymphocytosis and implicate cytomegalovirus as a likely antigenic stimulus for this disorder.


2016 ◽  
Vol 8 (332) ◽  
pp. 332ra46-332ra46 ◽  
Author(s):  
Qian Qi ◽  
Mary M. Cavanagh ◽  
Sabine Le Saux ◽  
Hong NamKoong ◽  
Chulwoo Kim ◽  
...  

Diversity and size of the antigen-specific T cell receptor (TCR) repertoire are two critical determinants for successful control of chronic infection. Varicella zoster virus (VZV) that establishes latency during childhood can escape control mechanisms, in particular with increasing age. We examined the TCR diversity of VZV-reactive CD4 T cells in individuals older than 50 years by studying three identical twin pairs and three unrelated individuals before and after vaccination with live attenuated VZV. Although all individuals had a small number of dominant T cell clones, the breadth of the VZV-specific repertoire differed markedly. A genetic influence was seen for the sharing of individual TCR sequences from antigen-reactive cells but not for repertoire richness or the selection of dominant clones. VZV vaccination favored the expansion of infrequent VZV antigen–reactive TCRs, including those from naïve T cells with lesser boosting of dominant T cell clones. Thus, vaccination does not reinforce the in vivo selection that occurred during chronic infection but leads to a diversification of the VZV-reactive T cell repertoire. However, a single-booster immunization seems insufficient to establish new clonal dominance. Our results suggest that repertoire analysis of antigen-specific TCRs can be an important readout to assess whether a vaccination was able to generate memory cells in clonal sizes that are necessary for immune protection.


Blood ◽  
2009 ◽  
Vol 114 (11) ◽  
pp. 2244-2253 ◽  
Author(s):  
Michael Rist ◽  
Corey Smith ◽  
Melissa J. Bell ◽  
Scott R. Burrows ◽  
Rajiv Khanna

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.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 831-831
Author(s):  
Robert Q. Le ◽  
J. Joseph Melenhorst ◽  
Brenna Hill ◽  
Sarfraz Memon ◽  
Minoo Battiwalla ◽  
...  

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.


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