scholarly journals A hypomorphic allele of ZAP-70 reveals a distinct thymic threshold for autoimmune disease versus autoimmune reactivity

2009 ◽  
Vol 206 (11) ◽  
pp. 2527-2541 ◽  
Author(s):  
Lih-Yun Hsu ◽  
Ying Xim Tan ◽  
Zheng Xiao ◽  
Marie Malissen ◽  
Arthur Weiss
Keyword(s):  
T Cell ◽  
Autoimmune Disease ◽  
T Regulatory Cells ◽  
Mutant Mouse ◽  
Cell Receptor ◽  
Regulatory Cells ◽  
Tcr Signaling ◽  
Hypomorphic Mutation ◽  
Relative Contribution ◽  
Tcr Repertoire

ZAP-70 is critical for T cell receptor (TCR) signaling. Tyrosine to phenylalanine mutations of Y315 and Y319 in ZAP-70 suggest these residues function to recruit downstream effector molecules, but mutagenesis and crystallization studies reveal that these residues also play an important role in autoinhibition ZAP-70. To address the importance of the scaffolding function, we generated a zap70 mutant mouse (YYAA mouse) with Y315 and Y319 both mutated to alanines. These YYAA mice reveal that the scaffolding function is important for normal development and function. Moreover, the YYAA mice have many similarities to a previously identified ZAP-70 mutant mouse, SKG, which harbors a distinct hypomorphic mutation. Both YYAA and SKG mice have impaired T cell development and hyporesponsiveness to TCR stimulation, markedly reduced numbers of thymic T regulatory cells and defective positive and negative selection. YYAA mice, like SKG mice, develop rheumatoid factor antibodies, but fail to develop autoimmune arthritis. Signaling differences that result from ZAP-70 mutations appear to skew the TCR repertoire in ways that differentially influence propensity to autoimmunity versus autoimmune disease susceptibility. By uncoupling the relative contribution from T regulatory cells and TCR repertoire during thymic selection, our data help to identify events that may be important, but alone are insufficient, for the development of autoimmune disease.

scholarly journals BDC12-4.1 T-Cell Receptor Transgenic Insulin-Specific CD4 T Cells Are Resistant to In Vitro Differentiation into Functional Foxp3+ T Regulatory Cells

PLoS ONE ◽  
2014 ◽  
Vol 9 (11) ◽  
pp. e112242 ◽  
Author(s):  
Ghanashyam Sarikonda ◽  
Georgia Fousteri ◽  
Sowbarnika Sachithanantham ◽  
Jacqueline F. Miller ◽  
Amy Dave ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cd4 T Cells ◽  
T Regulatory Cells ◽  
Cell Receptor ◽  
Regulatory Cells ◽  
In Vitro Differentiation

T-Cell Receptor Complementarity Determining Region Analysis of Peripheral Blood and Bone Marrow T-Lymphocyte Subsets and Quantitative Evaluation of T-Regulatory Cells in Patients with Chronic Idiopathic Neutropenia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1260-1260
Author(s):  
Michael Spanoudakis ◽  
Antonia Antoniou ◽  
Maria Velegraki ◽  
Katerina Pyrovolaki ◽  
Maria Ximeri ◽  
...  
Keyword(s):  
T Cell ◽  
Size Distribution ◽  
T Regulatory Cells ◽  
Cell Receptor ◽  
Cell Fraction ◽  
Healthy Controls ◽  
Regulatory Cells ◽  
Cd8 Cells ◽  
Chronic Idiopathic Neutropenia ◽  
Complementarity Determining Region

Abstract Clonal/oligoclonal expansions of cytotoxic T-lymphocytes (CTLs) and quantitative/qualitative abnormalities of T-regulatory cells (Tregs) have been implicated in the pathophysiology of acquired bone marrow (BM) failure syndromes such as aplastic anemia, myelodysplastic syndromes and large granular lymphocyte proliferative disease. Chronic Idiopathic Neutropenia (CIN) is an acquired disorder of granulopoiesis characterised by increased apoptosis of BM CD34+/CD33+ granulocytic progenitor cells. We have previously provided evidence for oligoclonal T-cell expansions with possible pathogenetic significance in CIN. The aim of the current study is (a) to define and compare the magnitude of CD4+ and CD8+ T-cell responses and (b) to evaluate the number of Tregs, in the peripheral blood (PB) and BM of CIN patients. Eighty five CIN patients and 85 healthy controls, age- and sex-matched to the patients, were studied after informed consent. All patients had PB neutrophil counts below 1800/μL (mean 1410 ± 330 neutrophils/μL, range 100–1799 neutrophils/μL), displayed negative anti-neutrophil antibody activity and were satisfying the previously reported diagnostic criteria for the disease.The T-cell receptor (TCR)-Vβ repertoire was analysed by flow cytometry (Vβ spectratyping) in the PB and BM CD3+, CD4+ and CD8+ cells. The size distribution of the TCR-Vβ complementarity determining region 3 (CDR3) was analysed in immunomagnetically sorted PB and BM CD4+ and CD8+ cells by PCR according to the -2 protocol using a fluorescence-based DNA sequencer (CDR3 spectratyping). Vβ family expansions were defined as above of 2 standard deviations from the mean values of the 85 healthy controls. CDR3 oligoclonal/monoclonal patterns were defined upon comparison with the normal Gaussian-type size distribution. The Treg cell frequency was defined as the proportion of FOXP3+ cells within the CD4+/CD25high PB and BM cell fraction by flow cytometry. We found that 69.41% and 82.61% of CIN patients displayed one or more predominant TCR-Vβ family expansions within the CD3+ cell fraction of PB and BM, respectively. None of the controls displayed clonal/oligoclonal expansions in either PB or BM (P<0.001 and P<0.001, respectively). Further analysis showed that 58.62% and 74.19% of CIN patients displayed a skewed TCR-Vβ repertoire in PB CD4+ and CD8+ cells, respectively. A higher proportion of patients i.e. 93.75% and 75.0% displayed a skewed TCR-Vβ repertoire in BM CD4+ and CD8+ cells, respectively. The total sum of predominant TCR-Vβ clones was statistically significant increased in patients’ BM compared to PB in all subpopulations studied, namely the CD3+, CD4+ and CD8+ cells (P<0.05, P<0.05, P<0.05, respectively). Interestingly, CDR3 spectratyping identified a skewed (oligoclonal) pattern in PB and/or BM CD8+ cells in 100% of patients. PCR analysis of PB and BM CD4+ cells revealed a normal Gaussian-like CDR3 size distribution in all but three patients. None of the controls displayed a skewed CDR3 profile in either CD4+ or CD8+ cells. The percentage of FOXP3+ cells within the PB CD4+CD25high cell fraction was significantly decreased in CIN patients (57.77%±15.77%) compared to controls (72.95±12.23%; P=0.0004). A parallel analysis of Treg cell proportion in patients’ PB and BM showed statistically significant increased percentage of FOX3+ cells within the CD4+/CD25high T-cells of BM (68.51%±11.88%) compared to PB (52.20%±12.77%) (P=0.0005). No statistically significant difference was found in the percentage of FOX3+ cells within the CD4+/CD25high T-cells of BM compared to PB in healthy controls. These data suggest that oligoclonal CTL expansions are uniformly identified in CIN patients. The polarized cell subsets are more frequent in BM than the PB suggesting the possible existence of “target” within the BM. Whether, however, the CD34+/CD33+ BM cells represent the target or the innocent bystanders of this immune process, remains elusive. The low frequency of Tregs in the PB and the accumulation of these cells in patients’ BM represents probably a compensatory control mechanism aiming to suppress the local immune reactions. All these data substantiate further the concept that CIN belongs to the spectrum of T-cell mediated BM failure syndromes.

scholarly journals Proinsulin-specific T regulatory cells may control immune responses in type 1 diabetes: implications for adoptive therapy

2020 ◽  
Vol 8 (1) ◽  
pp. e000873 ◽  
Author(s):  
Mateusz Gliwiński ◽  
Dorota Iwaszkiewicz-Grześ ◽  
Anna Wołoszyn-Durkiewicz ◽  
Monika Tarnowska ◽  
Magdalena Żalińska ◽  
...  
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
T Cell ◽  
Immune Responses ◽  
T Regulatory Cells ◽  
Cell Receptor ◽  
Regulatory Cells ◽  
Antigen Specificity ◽  
Adoptive Therapy

ObjectiveHere we looked for possible mechanisms regulating the progression of type 1 diabetes mellitus (T1DM). In this disease, autoaggressive T cells (T conventional cells, Tconvs) not properly controlled by T regulatory cells (Tregs) destroy pancreatic islets.Research design and methodsWe compared the T-cell compartment of patients with newly diagnosed T1DM (NDT1DM) with long-duration T1DM (LDT1DM) ones. The third group consisted of patients with LDT1DM treated previously with polyclonal Tregs (LDT1DM with Tregs). We have also looked if the differences might be dependent on the antigen specificity of Tregs expanded for clinical use and autologous sentinel Tconvs.ResultsPatients with LDT1DM were characterized by T-cell immunosenescence-like changes and expansion of similar vβ/T-cell receptor (TCR) clones in Tconvs and Tregs. The treatment with Tregs was associated with some inhibition of these effects. Patients with LDT1DM possessed an increased percentage of various proinsulin-specific T cells but not GAD65-specific ones. The percentages of all antigen-specific subsets were higher in the expansion cultures than in the peripheral blood. The proliferation was more intense in proinsulin-specific Tconvs than in specific Tregs but the levels of some proinsulin-specific Tregs were exceptionally high at baseline and remained higher in the expanded clinical product than the levels of respective Tconvs in sentinel cultures.ConclusionsT1DM is associated with immunosenescence-like changes and reduced diversity of T-cell clones. Preferential expansion of the same TCR families in both Tconvs and Tregs suggests a common trigger/autoantigen responsible. Interestingly, the therapy with polyclonal Tregs was associated with some inhibition of these effects. Proinsulin-specific Tregs appeared to be dominant in the immune responses in patients with T1DM and probably associated with better control over respective autoimmune Tconvs.Trial registration numberEudraCT 2014-004319-35.

scholarly journals T cell receptor (TCR) usage determines disease susceptibility in experimental autoimmune encephalomyelitis: studies with TCR V beta 8.2 transgenic mice.

1994 ◽  
Vol 179 (5) ◽  
pp. 1659-1664 ◽  
Author(s):  
V K Kuchroo ◽  
M Collins ◽  
A al-Sabbagh ◽  
R A Sobel ◽  
M J Whitters ◽  
...  
Keyword(s):  
T Cell ◽  
Autoimmune Disease ◽  
Transgenic Mice ◽  
T Cell Receptor ◽  
Proteolipid Protein ◽  
Cell Receptor ◽  
Myelin Proteins ◽  
Laboratory Animals ◽  
Cell Repertoire ◽  
Tcr Repertoire

Experimental allergic encephalomyelitis (EAE) is an autoimmune disease that can be induced in laboratory animals by immunization with the major myelin proteins, myelin basic protein (MBP) and proteolipid protein (PLP). We analyzed the role of the T cell receptor (TCR) repertoire in susceptibility to EAE induced by these two autoantigens. Autoreactive T cells induced after immunization with MBP use a limited set of TCR. In contrast, we demonstrate that T cell clones that recognize the encephalitogenic PLP epitope (PLP 139-151) use diverse TCR genes. When the TCR repertoire is limited by introduction of a novel rearranged TCR V beta 8.2 chain in transgenic SJL mice, EAE could be induced in the transgenic mice by immunization with the encephalitogenic epitopes of PLP, but not with the encephalitogenic epitope of MBP. Thus, skewing the TCR repertoire affects the susceptibility to EAE by immunization with MBP but not with PLP. These data demonstrate the biological consequences of the usage of a more diverse T cell repertoire in the development of an autoimmune disease.

scholarly journals Targeting CAR to the Peptide-MHC Complex Reveals Distinct Signaling Compared to That of TCR in a Jurkat T Cell Model

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 867
Author(s):  
Ling Wu ◽  
Joanna Brzostek ◽  
Shvetha Sankaran ◽  
Qianru Wei ◽  
Jiawei Yap ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Model ◽  
Cell Receptor ◽  
Target Cells ◽  
Tcr Signaling ◽  
Barr Virus ◽  
Car T ◽  
Epstein Barr ◽  
Lower Magnitude

Chimeric antigen receptor T cells (CAR-T) utilize T cell receptor (TCR) signaling cascades and the recognition functions of antibodies. This allows T cells, normally restricted by the major histocompatibility complex (MHC), to be redirected to target cells by their surface antigens, such as tumor associated antigens (TAAs). CAR-T technology has achieved significant successes in treatment of certain cancers, primarily liquid cancers. Nonetheless, many challenges hinder development of this therapy, such as cytokine release syndrome (CRS) and the efficacy of CAR-T treatments for solid tumors. These challenges show our inadequate understanding of this technology, particularly regarding CAR signaling, which has been less studied. To dissect CAR signaling, we designed a CAR that targets an epitope from latent membrane protein 2 A (LMP2 A) of the Epstein–Barr virus (EBV) presented on HLA*A02:01. Because of this, CAR and TCR signaling can be compared directly, allowing us to study the involvement of other signaling molecules, such as coreceptors. This comparison revealed that CAR was sufficient to bind monomeric antigens due to its high affinity but required oligomeric antigens for its activation. CAR sustained the transduced signal significantly longer, but at a lower magnitude, than did TCR. CD8 coreceptor was recruited to the CAR synapse but played a negligible role in signaling, unlike for TCR signaling. The distinct CAR signaling processes could provide explanations for clinical behavior of CAR-T therapy and suggest ways to improve the technology.

scholarly journals Human Cd25+Cd4+ T Regulatory Cells Suppress Naive and Memory T Cell Proliferation and Can Be Expanded in Vitro without Loss of Function

2001 ◽  
Vol 193 (11) ◽  
pp. 1295-1302 ◽  
Author(s):  
Megan K. Levings ◽  
Romina Sangregorio ◽  
Maria-Grazia Roncarolo
Keyword(s):  
T Cell ◽  
Peripheral Blood ◽  
T Regulatory Cells ◽  
Transforming Growth Factor ◽  
Cytotoxic T Lymphocyte ◽  
Cell Receptor ◽  
Major Advance ◽  
Loss Of Function

Active suppression by T regulatory (Tr) cells plays an important role in the downregulation of T cell responses to foreign and self-antigens. Mouse CD4+ Tr cells that express CD25 possess remarkable suppressive activity in vitro and in autoimmune disease models in vivo. Thus far, the existence of a similar subset of CD25+CD4+ Tr cells in humans has not been reported. Here we show that human CD25+CD4+ Tr cells isolated from peripheral blood failed to proliferate and displayed reduced expression of CD40 ligand (CD40L), in response to T cell receptor–mediated polyclonal activation, but strongly upregulated cytotoxic T lymphocyte–associated antigen (CTLA)-4. Human CD25+CD4+ Tr cells also did not proliferate in response to allogeneic antigen-presenting cells, but they produced interleukin (IL)-10, transforming growth factor (TGF)-β, low levels of interferon (IFN)-γ, and no IL-4 or IL-2. Importantly, CD25+CD4+ Tr cells strongly inhibited the proliferative responses of both naive and memory CD4+ T cells to alloantigens, but neither IL-10, TGF-β, nor CTLA-4 seemed to be directly required for their suppressive effects. CD25+CD4+ Tr cells could be expanded in vitro in the presence of IL-2 and allogeneic feeder cells and maintained their suppressive capacities. These findings that CD25+CD4+ Tr cells with immunosuppressive effects can be isolated from peripheral blood and expanded in vitro without loss of function represent a major advance towards the therapeutic use of these cells in T cell–mediated diseases.

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