Skewing of the T Cell Receptor Gene Repertoire and Public Clonotypes in Cytotoxic T Cells of Patients with Chronic Idiopathic Neutropenia: A Role for Antigen Selection in Disease Development

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 831-831
Author(s):  
Evangelia Stalika ◽  
Michalis Spanoudakis ◽  
Nikos Darzentas ◽  
Maria Karypidou ◽  
Achilles Anagnostopoulos ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Conflicts Of Interest ◽  
Sequence Data ◽  
Cytotoxic T Cell ◽  
Gene Rearrangements ◽  
Gene Repertoire ◽  
Autoimmune Reaction ◽  
Chronic Idiopathic Neutropenia ◽  
Antigen Selection

Abstract Abstract 831 Chronic idiopathic neutropenia (CIN) is a disorder of neutrophil production usually characterized by benign and asymptomatic course and female predominance. The defective hematopoiesis in CIN can be mainly attributed to accelerated Fas-mediated death of the CD34+/CD33+ granulocytic progenitor cells, secondary to an inflammatory bone marrow (BM) microenvironment. Crucial to CIN pathogenesis are the increased numbers of activated T cells identified in both peripheral blood (PB) and BM of CIN patients. Recently, using flow cytometry and CDR3 spectratyping, we obtained for the first time evidence for expanded T cell populations alluding to repertore skewing in both PB and BM of patients with CIN, but more prominent in the BM CD8+ subset. Prompted by these fndings, here we significantly extended our studies of the cytotoxic T cell responses in CIN in order to obtain a comprehensive view of the role of antigen selection in CIN pathogenesis. The study included 18 patients with CIN, 17 females and 1 male, diagnosed according to the established criterial for CIN. TRBV-TRBD-TRBJ gene rearrangements were amplified on either genomic DNA or cDNA isolated from CD8+ cells of PB (n=6) or BM (n=12) samples. PCR products were subcloned by transformation into E.Coli/TOP10F' competent bacteria and individual colonies were chosen randomly and subjected to Sanger sequencing. Sequence data were analyzed using the International imMunoGenetics information system and more particularly the IMGT/V-QUEST tool. Overall, 507 TRBV-TRBD-TRBJ gene rearrangements were analyzed (19-30/case) of which 466 were productive since they used functional TRBV genes and also carried in-frame CDR3s. A polyclonal profile was seen in only 3/18 cases (16.7%). The remaining cases were found to carry clusters of identical rearrangements corresponding to distinct immunodominant clonotypes. The frequency of each clonotype was determined by dividing the number of identical sequences by the total number of subcloned sequences analyzed. In 10/18 cases (55.5%), the dominant clonotype accounted for 12.8–22.6% of the total, whereas in 5/18 cases (27.8%) it accounted for 34.2–68.4% of the total. The TRBV28 gene was used by the dominant clonotype of three different CIN cases; the TRBV10-2, TRBV10-3, TRB19, and TRBV7-8 genes were identified in the major clonotypes of two cases each. Importantly, cluster analysis of the CDR3 sequences of all CIN cases of the present study identified 4 different rearrangements that were shared by different patients (public clonotypes). In conclusion, the present study strongly suggests that CIN may result from an autoimmune reaction directed against granulocytic progenitors triggered by a restricted range of, as yet, unidentified antigen(s). The finding of public clonotypes may indicate that public antigenic stimuli and/or shared immune processes underlie CIN development, at least for a proportion of cases. Overall, our results further support the concept that CIN may share common pathophysiologic mechanisms with other disorders characterized by T-cell and cytokine mediated suppression of hematopoiesis, perhaps representing a milder extreme within the spectrum of these acquired immune-mediated BM failure syndromes. Disclosures: No relevant conflicts of interest to declare.

High-Throughput Profiling of the T-Cell Receptor Gene Repertoire Supports Antigen Drive in the Pathogenesis of Chronic Idiopathic Neutropenia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2731-2731 ◽  
Author(s):  
Evangelia Stalika ◽  
Anastasia Hadzidimitriou ◽  
Athanasios Gkoufas ◽  
Maria Karypidou ◽  
Semeli Mastrodemou ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Sanger Sequencing ◽  
Conflicts Of Interest ◽  
Receptor Gene ◽  
Cell Receptor ◽  
Local Alignment ◽  
Gene Rearrangements ◽  
Gene Repertoire ◽  
Chronic Idiopathic Neutropenia

Abstract Chronic idiopathic neutropenia (CIN) is an acquired disorder of granulopoiesis characterized by prolonged neutropenia, mainly affecting middle-age females of the HLA-DRB1*1302 type. The defective hematopoiesis in CIN can be mainly attributed to accelerated Fas-mediated death of the CD34+/CD33+ granulocytic progenitors, secondary to an inflammatory bone marrow (BM) microenvironment. Crucial to CIN pathogenesis are the increased numbers of activated T cells identified in both peripheral blood (PB) and BM of CIN patients, supporting an immune pathogenesis. Using Sanger sequencing, we previously reported that the T-cell receptor (TR) gene repertoire in CIN is skewed, indicating antigen selection in CIN ontogeny. However, the analytical depth afforded by Sanger sequencing is limited, hindering definitive conclusions. In order to obtain a truly comprehensive view into the role of antigen drive in CIN, using next generation sequencing (NGS) we interrogated the TR repertoire of 13 patients (8 females, 5 males) included in our previous study as well as a healthy female. TRBV-TRBD-TRBJ gene rearrangements were amplified according to the BIOMED2 protocol on either genomic DNA or cDNA isolated from CD8+ cells of PB (n=4) or BM (n=10) samples. PCR products were used as a substrate for paired-end sample preparation (Illumina) and subjected to NGS on the MiSeq Illumina Platform. The raw NGS data were preprocessed with a dedicated pipeline for this purpose, including: (i) quality filtering of each read; (ii) merging of paired-end reads via local alignment; (iii) preparation of fasta files for submission to the IMGT/High V-QUEST tool; and, (iv) IMGT/High V-QUEST metadata analysis, interpretation and visualization. Overall, 6,196,980 TRBV-TRBD-TRBJ gene rearrangements were analyzed (130,020-1,037,680 /case) of which 5,317,609 were productive since they used functional TRBV genes and also carried in-frame CDR3. Rearrangements with identical TRBV gene usage and CDR3 sequence were defined as clonotypes. For repertoire analyses, clonotypes rather than single rearrangement sequences were considered. Overall, 553,145 unique clonotypes were identified (median 39,510; range 7,732-172,253/case), of which 408,744 represented singletons. All clonotypes from the Sanger analysis were detected by NGS as well. Among the 46 functional TRBV genes identified, the most frequent were: TRBV29-1 (13.9%), TRBV19 (6.7%), TRBV12-3 (5.6%), TRBV6-5 (5.4%), TRBV27 (4.9%) and TRBV6-1 (4.0%), collectively accounting for 40,5% of the TRBV repertoire; the TRBV29-1 gene predominated in 9/13 CIN cases. All CIN cases were found to carry distinct expanded clonotypes (median 10,314; range 2,279-40,245/case). The predominant clonotype ranged in frequency from 5.25 to 20.2% of the total clonotypes observed in each case. This contrasts significantly (p<0.001) with a 0.47% frequency of the dominant clonotype in the healthy control. Cluster analysis of the sequences of all CIN cases identified 9034 different clonotypes shared by different patients and, thus, deemed as public. Notably, public clonotypes of a given CDR3 length could show high sequence similarity, further underscoring the restricted nature of the repertoire. As an example, 1632/2665 (61.2%) public clonotypes with 12 aminoacid-long CDR3 were grouped into 168 distinct communities, populated with 2-280 highly similar sequences, each linked with 1 aminoacid distance with at least another member of the community. Overall, the present study offers conclusive evidence that the TR repertoire in CIN is remarkably skewed. The finding of oligoclonal T-cell expansions and public clonotypes strongly indicates that antigen-driven immune responses are very likely implicated in the pathogenesis of CIN. Disclosures No relevant conflicts of interest to declare.

Construction and Molecular Characterization Of a T-Cell Receptor-Like Antibody and CAR-T Cells Specific For Minor Histocompatibility Antigen HA-1H

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4490-4490
Author(s):  
Yoko Inaguma ◽  
Yasushi Akahori ◽  
Yoshiki Akatsuka ◽  
Yuko Murayama ◽  
Keiko Shiraishi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Adoptive Immunotherapy ◽  
Conflicts Of Interest ◽  
Cytotoxic T Cell ◽  
Target Cells ◽  
Minimal Risk ◽  
Single Chain ◽  
Car T Cells ◽  
Car T

Selective graft-versus-tumor (GVT) reactivity with minimal risk of graft-versus-host disease (GVHD) following allogeneic stem cell transplantation is thought to be induced by targeting minor histocompatibility (H) antigens (Ags) expressed only on patients’ hematopoietic cells. Among HLA-A* 02:01 positive patients, minor H Ags such as HA-1 and HA-2 have been shown to be associated with anti-tumor responses with minimal GVHD and explored for application to adoptive immunotherapy. Because preparation of Ag-specific cytotoxic T cell clones (CTLs) or lines for adoptive immunotherapy is labor-intensive and time consuming, the genetic transfer of T-cell receptors (TCRs) directed toward target Ags into T lymphocytes has been used to efficiently generate anti-tumor T cells without the need for in vitro induction and expansion. Alternatively, T cells could be gene-modified with a chimeric antigen receptor (CAR) harnessing a single chain antibody moiety (scFv). The conventional CAR strategy has the limitation of only targeting cell surface Ags on target cells. One possible way to attain intracellular Ag targeting with a CAR is to generate a TCR-like monoclonal antibody (mAb) as a source of scFv. In this study, we sought to generate highly specific mAbs specific for HA-1H minor H Ag by immunizing mice with tetramerized recombinant HLA-A2 incorporating HA-1H minor H Ag peptides and β2-microglobulin (HA-1H/HLA-A2). We hypothesized that the use of HLA-A2 transgenic mice, which should be tolerant to human HLA-A2, would facilitate efficient induction of mAbs specific for peptides presented on HLA-A2. Phage libraries were generated from splenic B cells and screened by panning for clones reactive to plate-bound HA-1H/HLA-A2 in the presence of free MAGEA4/HLA-A2 for competition. Candidate scFv encoded by obtained phage clones were transformed to scFv tetrameric Ab form or introduced into T cells as CAR coupled to CD28 transmembrane and CD3ζ domains (CD28-ζ). A total of 144 clones were randomly selected from 8.1×108 clones that had been recovered after the third panning. Among 144 clones, 18 (12.5%) showed preferential binding to HA-1/HLA-A2, 137 showed similar binding to both pMHC complexes, and 7 showed reactivity to neither of them. One of 18 scFv Abs, clone #131, demonstrated high affinity (KD = 8.34nM) for the HA-1H/HLA-A2 complex. Primary human CD8 T cells transduced with #131 scFv-CD28-ζ were stained with HA-1H/HLA-A2 tetramers as strongly as a CTL clone, EH6, specific for endogenously HLA-A2- and HA-1H-positive cells. Unexpectedly, however, #131 scFv-CD28-ζ CAR-T cells required ∼100-fold higher Ag density when pulsed exogenously to exert cytotoxicity than did the cognate EH6-CTL. In addition, mAb blocking experiments demonstrated that #131 scFv-CD28-ζCAR-T cells were less sensitive to CD8 blockade when they were completely blocked with HA-1H/HLA-A2 tetramer. These data suggest that T cells with higher affinity antigen receptors than TCRs (average KD ranging between 1μM∼100μM) are less able to recognize low density peptide/MHC antigens as reported in the case of affinity-matured TCR or CAR, and that CD8+ CAR-T cells may not be necessarily CD8-dependent possibly due to failure to form complexes with CD3. Disclosures: No relevant conflicts of interest to declare.

Molecular Immunoprofiling the T Cell Repertoire after Rituximab Administration Reveals Frequent Oligoclonality Albeit with Different Patterns Depending on the Clinical Context

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5792-5792
Author(s):  
Apostolia Papalexandri ◽  
Michail Iskas ◽  
Evangelia Stalika ◽  
Maria Karypidou ◽  
Barbara Tachynopoulou ◽  
...  
Keyword(s):  
T Cell ◽  
Research Funding ◽  
Late Onset ◽  
Sequence Data ◽  
Lymphocytic Leukemia ◽  
Cytotoxic T Cell ◽  
Cell Populations ◽  
Gene Repertoire ◽  
Group A ◽  
Group B

Abstract In patients with B lymphoid malignancies, depletion of B cells by Rituximab, an anti-CD20 humanized monoclonal antibody, can induce changes in the subset composition, activation and function of T cells. The spectrum of resultant immune-mediated sequelae encompasses organ-specific manifestations (e.g. pneumonitis, gastritis) as well as Rituximab-associated late onset neutropenia (R-LON). Although the pathogenesis of these clinical syndromes is not fully elucidated, evidence suggests that at least a fraction of cases may develop in a setting of expanded cytotoxic T cell populations with a large granular lymphocyte (LGL) phenotype (CD3+CD8+CD57+). Similar cytotoxic T cell expansions can be observed after Rituximab administration in other clinical settings e.g. allogeneic transplantation (allo-HCT), where selective restriction of the T-cell receptor (TR) gene repertoire is probably driven by multifactorial mechanisms. Here, we sought to obtain more insight into this phenomenon by molecular immunoprofiling of the TR gene repertoire in two groups of patients who received Rituximab: (i) Group A: patients (n=10) with chronic lymphocytic leukemia (CLL) treated with fludarabine-cyclophosphamide-rituximab (FCR); and, Group B: patients (n=14) who underwent allo-HCT for hematologic malignancies and received Rituximab either as pre-emptive treatment for EBV reactivation or against refractory cGvHD. Each patient included in the study received a mean of 6 cycles of Rituximab (range, 1-14). TR repertoire analysis was performed 11-88 (median, 36) and 5-24 months (median, 5) after the first Rituximab administration in Group A and Group B, respectively. TR beta gene rearrangements were PCR amplified on genomic DNA isolated from bone marrow samples using the BIOMED2 protocol and subjected to classic subcloning/Sanger sequencing. Sequence data were analyzed using the IMGT/V-QUEST tool. A total of 579 productive TRBV-TRBD-TRBJ rearrangements were analysed, 291 for Group A, 288 for Group B (6-91/case, median=20). Among the 46 TRBV functional genes identified, 3 accounted for >25% of cases in both groups: (i) TRBV27 (13% in both Groups A and B); ii) TRBV19-1 (13% in group A, 7% in group B); and, (iii) TRBV6-1 (7% and 6%, respectively). Clusters of identical (>=2) rearrangements corresponding to clonotypes were identified in all patients. Oligoclonality with immunodominant clonotypes (>12% of the repertoire) accounting for over 30% of the analyzed sequences was more frequent in Group A (7/10 cases) versus Group B (5/10 cases); however, larger clonotype expansions were seen in group B. Longitudinal analysis was performed in 3 patients with oligoclonality, 1 from group A and 2 from Group B: in the Group A patient, immunodominant clonotypes disappeared, while both patients in Group B retained the oligoclonal repertoire. Lymphocyte subpopulation analysis by flow cytometry was performed in 6 patients of each group. T-LGL proliferations (defined as CD4/CD8 abnormal ratio and CD3+CD8+CD57+ >30%) were found more often in Group B (3/6 cases in Group A versus 6/6 in Group B). They were related to oligoclonal TR gene repertoire in Group A (3/3) but not in Group B patients (3/6 cases). However, true expansions could be considered only in group B patients, since CD8+ lymphocytes >1.0*109/l were seen in all 6 Group B versus only 1/6 group A cases. Self-limiting R-LON was observed in 8 patients (4 in each group), but no association of oligoclonality to R-LON could be found. In conclusion, we report frequent development of oligoclonal T cell populations after Rituximab treatment in two different clinical contexts. The Groups analyzed differed with respect to the extent of oligoclonality, suggesting that the precise clinical setting determines the amplitude of TR repertoire skewing after Ritximab. Sustained oligoclonal cytotoxic expansions were recognised more often among allo-HCT patients, presenting with a highly restricted TR gene repertoire and likely reflecting strong antigenic stimulation by viruses and/or cGVHD aggravated by T cell imbalances induced by Rituximab. Disclosures Stamatopoulos: Gilead: Consultancy, Honoraria, Research Funding; Abbvie: Honoraria, Other: Travel expenses; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Other: Travel expenses, Research Funding.

Clonal Expansions of Cytotoxic T Cells in the Blood of Patients with Waldenstrom's Macroglobulinaemia Are Anergic and Disappear After Nucleoside Analogue Therapy.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1820-1820
Author(s):  
Ross D Brown ◽  
Jia Li ◽  
Daniel Sze ◽  
Mark Cowley ◽  
Warren Kaplan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Nucleoside Analogue ◽  
Conflicts Of Interest ◽  
Cytotoxic T Cells ◽  
Gene Set Enrichment Analysis ◽  
Cytotoxic T Cell ◽  
Monoclonal Gammopathies ◽  
Waldenstrom’S Macroglobulinaemia

Abstract Abstract 1820 Poster Board I-846 T cells contribute to the immunomodulatory control of the tumor in patients with monoclonal gammopathies. We previously found that CD3+CD8+CD57+TCRVβ+restricted cytotoxic T cell expansions were present in 48% of patients with multiple myeloma (n=221) and conferred a significant favorable prognosis. We now report the presence of these expansions in 70% of patients with Waldenstrom's Macroglobulinaemia (WM) (n=20) with a wide spectrum of the TCRVβ repertoire represented. Previous nucleoside analogue (NA) therapy, known to be associated with an increased incidence of transformation to aggressive lymphoma, significantly influenced the presence of TCRVβ expansions (χ2=11.6; p<0.001) as 5 of the 6 patients without and only 1 of the 14 patients with TCRVβ expansions had received NA. Clonality of CD3+CD8+CD57+TCRVβ-restricted cytotoxic T cells was confirmed by determining the size of the TCRVβ chain CDR3 region and by direct sequencing. We identified differential gene expression by using microarray analysis (Affymetrix GeneChip Human Genome U133 plus 2.0 Arrays) and confirmed the expression of selected genes by real-time qPCR and flow cytometry. Data was analysed by paired moderated t-test and then Gene Set Enrichment Analysis (GSEA) for pathway analysis. Clonal T cells not only had upregulated genes from cytotoxic pathways (granzyme B, perforin and FGFBP2) but also genes which suppress apoptosis, proliferation, cell cycle G1/S transition arrest and T cell activation (RAS, CSK and TOB pathways) indicating anergy which was validated by CFSE tracking of proliferation after antiCD3+antiCD28 stimulation. The current studies provide further evidence for the persistence and relevance of clonal T cells in monoclonal gammopathies. Disclosures No relevant conflicts of interest to declare.

T Cell Receptor Gene Repertoire Restriction in Chronic Lymphocytic Leukemia with Stereotyped IGHV4–34/IGKV2–30 Antigen Receptors

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3908-3908 ◽  
Author(s):  
Anna Vardi ◽  
Andreas Agathangelidis ◽  
Evangelia Stalika ◽  
Millaray Marincevic ◽  
Maria Karypidou ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Clonal Selection ◽  
Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Gene Repertoire ◽  
Time Points ◽  
Selection Of ◽  
Antigen Selection

Abstract Abstract 3908 Chronic lymphocytic leukemia (CLL) exhibits a remarkably skewed immunoglobulin (IG) gene repertoire mainly evident in the existence of subsets of patients with quasi-identical IGs in their B cell receptors (BcRs), collectively accounting for one-third of CLL patients. BcR stereotypy is strongly suggestive of clonal selection by a restricted set of antigens. However, it is not yet clear at which phase of clonal evolution these antigens act, or whether the stimulation is persistent. Furthermore, the possible role of antigens in the selection and activation of cognate T lymphocytes remains obscure yet highly relevant, given recent data about T cell interactions with CLL B cells and their tolerized behavior. Here, we analyzed the repertoire of T cell receptor β chain genes (TRB) in CLL expressing stereotyped IGHV4–34/IGKV2–30 BcR IGs (subset #4), which exhibit a series of immunogenetic features, such as pronounced intraclonal diversification of IG genes, suggestive of ongoing interactions with (auto)antigens. Furthermore, subset #4 CLL cells have distinctive functional responses to BcR and/or Toll-like receptor triggering, rendering this subset a paradigmatic example for seeking evidence of antigen selection also within the T cell population. We analyzed 18 peripheral blood samples of 12 untreated subset #4 patients (samples from different time points were analyzed in 4 cases). No case had evidence of infection at sampling. PCR amplicons for TRBV-TRBD-TRBJ gene rearrangements (BIOMED2 protocol) were subcloned by transformation into E. coli/TOP10F bacteria and randomly chosen individual colonies were subjected to Sanger sequencing. Only productive rearrangements (n=320, ranging from 14–52/case) were analyzed. All cases were found to carry clusters of identical rearrangements (≥2) corresponding to distinct clonotypes; the number of expanded clonotypes/case ranged from 1–13 (median 5). The relative frequency of each clonotype/case was determined by dividing the number of the corresponding identical sequences by the total number of subcloned sequences analyzed. The frequency of the most expanded (immunodominant) clonotype/case ranged from 8.1–70.4%. Collectively, the frequency of all expanded clonotypes/case ranged from 29.7–93.3%. In 2/4 cases that were analyzed at different time points, at least one clonotype was found to persist. Importantly, cluster analysis of the TRB CDR3 sequences of all cases identified ‘public’ clonotypes: 2 identical clonotypes (TRBV15*02/TRBD1*01/TRBJ2–2*01 and TRBV30*01/TRBD1*01/TRBJ2–2*01) each shared by a pairs of different patients and a highly similar clonotype shared by an additional pair of patients. In conclusion, the present study provides clear evidence of repertoire skewing among T cells in CLL patients belonging to subset #4, strongly supporting antigen selection. The finding of ‘public’ clonotypes raises the possibility that shared antigenic epitopes may be relevant for clonal selection of T cells in different subset #4 cases. Whether the antigens that drive T cell repertoire restriction are identical/related to those implicated in the selection of CLL progenitors of subset #4 or even the malignant cells themselves or whether they are tumor-associated antigens remains to be clarified. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Characterization of human T cells reactive with the Mycoplasma arthritidis-derived superantigen (MAM): generation of a monoclonal antibody against V beta 17, the T cell receptor gene product expressed by a large fraction of MAM-reactive human T cells.

1991 ◽  
Vol 174 (4) ◽  
pp. 891-900 ◽  
Author(s):  
S M Friedman ◽  
M K Crow ◽  
J R Tumang ◽  
M Tumang ◽  
Y Q Xu ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Activity ◽  
Cell Receptor ◽  
Cytotoxic T Cell ◽  
Mycoplasma Arthritidis ◽  
Human T Cells

While all known microbial superantigens are mitogenic for human peripheral blood lymphocytes (PBL), the functional response induced by Mycoplasma arthritidis-derived superantigen (MAM) is unique in that MAM stimulation of PBL consistently results in T cell-dependent B cell activation characterized by polyclonal IgM and IgG production. These immunostimulatory effects of MAM on the humoral arm of the human immune system warranted a more precise characterization of MAM-reactive human T cells. Using an uncloned MAM reactive human T cell line as immunogen, we have generated a monoclonal antibody (mAb) (termed C1) specific for the T cell receptor V beta gene expressed by the major fraction of MAM-reactive human T cells, V beta 17. In addition, a V beta 17- MAM-reactive T cell population exists, assessed by MAM, induced T cell proliferation and cytotoxic T cell activity. mAb C1 will be useful in characterizing the functional properties of V beta 17+ T cells and their potential role in autoimmune disease.

scholarly journals Indoleamine 2,3-dioxygenase specific, cytotoxic T cells as immune regulators

Blood ◽  
2011 ◽  
Vol 117 (7) ◽  
pp. 2200-2210 ◽  
Author(s):  
Rikke Bæk Sørensen ◽  
Sine Reker Hadrup ◽  
Inge Marie Svane ◽  
Mads Christian Hjortsø ◽  
Per thor Straten ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Effector T Cells ◽  
T Cell Immunity ◽  
Regulatory Function ◽  
Cytotoxic T Cell ◽  
Interleukin 17 ◽  
Patients With Cancer ◽  
Indoleamine 2,3 Dioxygenase ◽  
Cell Immunity

Abstract Indoleamine 2,3-dioxygenase (IDO) is an immunoregulatory enzyme that is implicated in suppressing T-cell immunity in normal and pathologic settings. Here, we describe that spontaneous cytotoxic T-cell reactivity against IDO exists not only in patients with cancer but also in healthy persons. We show that the presence of such IDO-specific CD8+ T cells boosted T-cell immunity against viral or tumor-associated antigens by eliminating IDO+ suppressive cells. This had profound effects on the balance between interleukin-17 (IL-17)–producing CD4+ T cells and regulatory T cells. Furthermore, this caused an increase in the production of the proinflammatory cytokines IL-6 and tumor necrosis factor-α while decreasing the IL-10 production. Finally, the addition of IDO-inducing agents (ie, the TLR9 ligand cytosine-phosphate-guanosine, soluble cytotoxic T lymphocyte–associated antigen 4, or interferon γ) induced IDO-specific T cells among peripheral blood mononuclear cells from patients with cancer as well as healthy donors. In the clinical setting, IDO may serve as an important and widely applicable target for immunotherapeutic strategies in which IDO plays a significant regulatory role. We describe for the first time effector T cells with a general regulatory function that may play a vital role for the mounting or maintaining of an effective adaptive immune response. We suggest terming such effector T cells “supporter T cells.”

scholarly journals Conditional deletion of cytokine receptor chains reveals that IL-7 and IL-15 specify CD8 cytotoxic lineage fate in the thymus

2012 ◽  
Vol 209 (12) ◽  
pp. 2263-2276 ◽  
Author(s):  
Tom M. McCaughtry ◽  
Ruth Etzensperger ◽  
Amala Alag ◽  
Xuguang Tai ◽  
Sema Kurtulus ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Conditional Knockout ◽  
Cytokine Receptor ◽  
T Cell Subsets ◽  
Cytotoxic T Cell ◽  
Lineage Specification ◽  
Class I Mhc ◽  
Mhc I

The thymus generates T cells with diverse specificities and functions. To assess the contribution of cytokine receptors to the differentiation of T cell subsets in the thymus, we constructed conditional knockout mice in which IL-7Rα or common cytokine receptor γ chain (γc) genes were deleted in thymocytes just before positive selection. We found that γc expression was required to signal the differentiation of MHC class I (MHC-I)–specific thymocytes into CD8+ cytotoxic lineage T cells and into invariant natural killer T cells but did not signal the differentiation of MHC class II (MHC-II)–specific thymocytes into CD4+ T cells, even into regulatory Foxp3+CD4+ T cells which require γc signals for survival. Importantly, IL-7 and IL-15 were identified as the cytokines responsible for CD8+ cytotoxic T cell lineage specification in vivo. Additionally, we found that small numbers of aberrant CD8+ T cells expressing Runx3d could arise without γc signaling, but these cells were developmentally arrested before expressing cytotoxic lineage genes. Thus, γc-transduced cytokine signals are required for cytotoxic lineage specification in the thymus and for inducing the differentiation of MHC-I–selected thymocytes into functionally mature T cells.

scholarly journals 65 Identification of frequently presented non-mutated tumor-specific immunogens for the development of both off-the-shelf and personalized vaccines without need for tumor biopsy

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A72-A72
Author(s):  
Orsolya Lorincz ◽  
Levente Molnar ◽  
Zsolt Csiszovszki ◽  
Eszter Somogyi ◽  
Jozsef Toth ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Colorectal Cancer ◽  
T Cells ◽  
T Cell ◽  
Metastatic Colorectal Cancer ◽  
Cancer Vaccines ◽  
T Cell Responses ◽  
Tumor Biopsy ◽  
Cell Responses ◽  
Antigen Selection

BackgroundVaccines have little chance of destroying heterogeneous tumor cells since they rarely induce polyclonal T-cell responses against the tumor. The main challenge is the accurate identification of tumor targets recognizable by T cells. Presently, 6–8% of neoepitopes selected based on the patients‘ tumor biopsies are confirmed as real T cell targets.1 2. To overcome this limitation, we developed a computational platform called Personal Antigen Selection Calculator (PASCal) that identifies frequently presented immunogenic peptide sequences built on HLA-genetics and tumor profile of thousands of real individuals.3 Here we show the performance of PASCal for the identification of both shared and personalized tumor targets in metastatic colorectal cancer (mCRC) and breast cancer subjects.MethodsExpression frequency of the tumor-specific antigens (TSAs) ranked in PASCal’s database (based on 7,548 CRC specimen) was compared to the RNA-sequencing data of CRC tumors obtained from TCGA. Using PASCal, 12 shared PEPIs (epitopes restricted to at least 3 HLA class I alleles of a subject from an in silico cohort) derived from 7 TSAs were selected as frequent targets (calculated probability: average 2.5 [95%CI 2.4–2.8] TSAs/patient). Spontaneous immune responses against each of the twelve 9mer peptides were determined by ELISpot using PBMCs of 10 mCRC subjects who participated in the OBERTO-101 study.4 PEPIs selected for a breast cancer subject based on her HLA genotype were also tested.ResultsEach of the 106 tumors analyzed expressed at least 13, average 15 of the 20 top-ranked TSAs in PASCal’s database confirming their prevalence in CRC. 7/10 subjects had spontaneous CD8+ T-cell responses against at least one peptide selected with PASCal. Each peptide (12/12) was recognized by at least one patient. Patients‘ T-cells reacted with average 3.6/12 (30%) peptides confirming the expression of average 2.8 [95%CI 1.0–4.6] TSAs (n=10). After HLA-matching, among the subjects for whom we could select at least 4 PEPIs (average 5) from the list of 12 peptides (n=6), average 2.5 (50%) peptides were positive. Of the 12 PEPIs selected with PASCal for a breast cancer subject, we detected spontaneous T-cell responses against 9 PEPIs, indicating that at least 75% of the selected peptides were present in the subject’s tumor and were recognized by T-cells.ConclusionsPASCal platform accommodates both tumor- and patient heterogeneity and identifies non-mutated tumor targets that may trigger polyclonal cytotoxic T-cell responses. It is a rapid tool for the design of both off-the-shelf and personalized cancer vaccines negating the need for tumor biopsy.ReferencesWells DK, van Buuren MM, Dang KK, et al. Key parameters of tumor epitope immunogenicity revealed through a consortium approach improve neoantigen prediction. Cell 2020:183(3):818–34.e13.Bulik-Sullivan B, Busby J, Palmer CD, et al. Deep learning using tumor HLA peptide mass spectrometry datasets improves neoantigen identification. Nat Biotech 2018:37:55–63.Somogyi E, Csiszovszki Z, Lorincz O, et al. 1181PDPersonal antigen selection calculator (PASCal) for the design of personal cancer vaccines. Annal Oncol 2019:30(Supplement_5):v480-v81.Hubbard J, Cremolini C, Graham R, et al. P329 PolyPEPI1018 off-the shelf vaccine as add-on to maintenance therapy achieved durable treatment responses in patients with microsatellite-stable metastatic colorectal cancer patients (MSS mCRC). J ImmunoTher Cancer 2019:7(1):282.

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