Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Targeted loss of SHP1 in murine thymocytes dampens TCR signaling late in selection.

ABSTRACT: SHP1 is a tyrosine phosphatase critical to proximal regulation of TCR signaling. Here, analysis of CD4-Cre SHP1(fl/fl) conditional knockout thymocytes using CD53, TCR?, CD69, CD4, and CD8? expression demonstrates the importance of SHP1 in the survival of post selection (CD53(+) ), single-positive thymocytes. Using Ca(2+) flux to assess the intensity of TCR signaling demonstrated that SHP1 dampens the signal strength of these same mature, postselection thymocytes. Consistent with its dampening effect, TCR signal strength was also probed functionally using peptides that can mediate selection of the OT-I TCR, to reveal increased negative selection mediated by lower-affinity ligand in the absence of SHP1. Our data show that SHP1 is required for the survival of mature thymocytes and the generation of the functional T-cell repertoire, as its absence leads to a reduction in the numbers of CD4(+) and CD8(+) naïve T cells in the peripheral lymphoid compartments.

SUBMITTER: Martinez RJ

PROVIDER: S-EPMC5208044 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Targeted loss of SHP1 in murine thymocytes dampens TCR signaling late in selection.

Martinez Ryan J RJ Morris Anna B AB Neeld Dennis K DK Evavold Brian D BD

European journal of immunology 20160901 9

SHP1 is a tyrosine phosphatase critical to proximal regulation of TCR signaling. Here, analysis of CD4-Cre SHP1(fl/fl) conditional knockout thymocytes using CD53, TCRβ, CD69, CD4, and CD8α expression demonstrates the importance of SHP1 in the survival of post selection (CD53(+) ), single-positive thymocytes. Using Ca(2+) flux to assess the intensity of TCR signaling demonstrated that SHP1 dampens the signal strength of these same mature, postselection thymocytes. Consistent with its dampening ef ...[more]

PMID: 27354309

Similar Datasets

THEMIS increases TCR signaling in CD4+CD8+ thymocytes by inhibiting the activity of the tyrosine phosphatase SHP1.

Project description:The T cell lineage-restricted protein THEMIS plays a critical role in T cell development at the positive selection stage. In the SHP1 activation model, THEMIS is proposed to enhance the activity of the tyrosine phosphatase SHP1 (encoded by Ptpn6), thereby dampening T cell antigen receptor (TCR) signaling and preventing the inappropriate negative selection of CD4+CD8+ thymocytes by positively selecting ligands. In contrast, in the SHP1 inhibition model, THEMIS is proposed to suppress SHP1 activity, rendering CD4+CD8+ thymocytes more sensitive to TCR signaling initiated by low-affinity ligands to promote positive selection. We sought to resolve the controversy regarding the molecular function of THEMIS. We found that the defect in positive selection in Themis-/- thymocytes was ameliorated by pharmacologic inhibition of SHP1 or by deletion of Ptpn6 and was exacerbated by SHP1 overexpression. Moreover, overexpression of SHP1 phenocopied the Themis-/- developmental defect, whereas deletion of Ptpn6, Ptpn11 (encoding SHP2), or both did not result in a phenotype resembling that of Themis deficiency. Last, we found that thymocyte negative selection was not enhanced but was instead impaired in the absence of THEMIS. Together, these results provide evidence favoring the SHP1 inhibition model, supporting a mechanism whereby THEMIS functions to enhance the sensitivity of CD4+CD8+ thymocytes to TCR signaling, enabling positive selection by low-affinity, self-ligand-TCR interactions.

| S-EPMC10410529 | biostudies-literature

The Protein Phosphatase Shp1 Regulates Invariant NKT Cell Effector Differentiation Independently of TCR and Slam Signaling.

Project description:Invariant NKT (iNKT) cells are innate lipid-reactive T cells that develop and differentiate in the thymus into iNKT1/2/17 subsets, akin to TH1/2/17 conventional CD4 T cell subsets. The factors driving the central priming of iNKT cells remain obscure, although strong/prolonged TCR signals appear to favor iNKT2 cell development. The Src homology 2 domain-containing phosphatase 1 (Shp1) is a protein tyrosine phosphatase that has been identified as a negative regulator of TCR signaling. In this study, we found that mice with a T cell-specific deletion of Shp1 had normal iNKT cell numbers and peripheral distribution. However, iNKT cell differentiation was biased toward the iNKT2/17 subsets in the thymus but not in peripheral tissues. Shp1-deficient iNKT cells were also functionally biased toward the production of TH2 cytokines, such as IL-4 and IL-13. Surprisingly, we found no evidence that Shp1 regulates the TCR and Slamf6 signaling cascades, which have been suggested to promote iNKT2 differentiation. Rather, Shp1 dampened iNKT cell proliferation in response to IL-2, IL-7, and IL-15 but not following TCR engagement. Our findings suggest that Shp1 controls iNKT cell effector differentiation independently of positive selection through the modulation of cytokine responsiveness.

| S-EPMC6457124 | biostudies-literature

Unaltered negative selection and Treg development of self-reactive thymocytes in TCR transgenic Fyn-deficient mice.

Project description:The tyrosine kinase Fyn has been implicated as playing an important role in the generation of both stimulatory and inhibitory signaling events induced by TCR engagement. To assess the role of Fyn for antigen-driven negative selection and Treg development, which are both dependent on the strength and nature of TCR signaling, we generated mice that co-express the transgenes for OVA and the OT-II TCR, which recognizes a peptide from OVA. In mice expressing both transgenes, negative selection, Treg development in the thymus, and the number of Treg in the periphery were each unaffected by ablation of Fyn. Moreover, fyn(-/-) Treg were functional, as assessed in vitro. We further tested the role of Fyn for the adaptor function of c-Cbl, using mice containing a point mutation in c-Cbl that abolishes its E3 ubiquitin ligase function but maintains its adaptor function. The functional and signaling properties of this mutant c-Cbl were unaltered in fyn(-/-) thymocytes. Combined, these data indicate that Fyn was not required for the induction of central tolerance by negative selection, the adaptor protein role of c-Cbl, or the normal development and function of Treg.

| S-EPMC2976765 | biostudies-literature

Ubc9 Is Required for Positive Selection and Late-Stage Maturation of Thymocytes.

Project description:SUMOylation is an important posttranslational modification that regulates protein function in diverse biological processes. However, its role in early T cell development has not been genetically studied. UBC9 is the only E2 enzyme for all SUMOylation. In this study, by selectively deleting Ubc9 gene in T cells, we have investigated the functional roles of SUMOylation in T cell development. Loss of Ubc9 results in a significant reduction of CD4 and CD8 single-positive lymphocytes in both thymus and periphery. Ubc9-deficient cells exhibit defective late-stage maturation post the initial positive selection with increased apoptosis and impaired proliferation, among which attenuated IL-7 signaling was correlated with the decreased survival of Ubc9-deficent CD8 single-positive cells. Furthermore, NFAT nuclear retention induced by TCR signals was regulated by SUMOylation during thymocytes development. Our study thus reveals a novel posttranslational mechanism underlying T cell development.

| S-EPMC5392730 | biostudies-literature

Transforming Growth Factor-beta signaling in αβ thymocytes promotes negative selection.

Project description:In the thymus, the T lymphocyte repertoire is purged of a substantial portion of highly self-reactive cells. This negative selection process relies on the strength of TCR-signaling in response to self-peptide-MHC complexes, both in the cortex and medulla regions. However, whether cytokine-signaling contributes to negative selection remains unclear. Here, we report that, in the absence of Transforming Growth Factor beta (TGF-β) signaling in thymocytes, negative selection is significantly impaired. Highly autoreactive thymocytes first escape cortical negative selection and acquire a Th1-like-phenotype. They express high levels of CXCR3, aberrantly accumulate at the cortico-medullary junction and subsequently fail to sustain AIRE expression in the medulla, escaping medullary negative selection. Highly autoreactive thymocytes undergo an atypical maturation program, substantially accumulate in the periphery and induce multiple organ-autoimmune-lesions. Thus, these findings reveal TGF-β in thymocytes as crucial for negative selection with implications for understanding T cell self-tolerance mechanisms.

| S-EPMC6923358 | biostudies-literature

IL-23 promotes TCR-mediated negative selection of thymocytes through the upregulation of IL-23 receptor and ROR?t.

Project description:Transient thymic involution is frequently found during inflammation, yet the mode of action of inflammatory cytokines is not well defined. Here we report that interleukin-23 (IL-23) production by the thymic dendritic cells (DCs) promotes apoptosis of the CD4(hi)CD8(hi) double-positive (DP) thymocytes. A deficiency in IL-23 signalling interferes with negative selection in the male D(b)/H-Y T-cell receptor (TCR) transgenic mice. IL-23 plus TCR signalling results in significant upregulation of IL-23 receptor (IL-23R) expressed predominantly on CD4(hi)CD8(hi)CD3(+)??TCR(+) DP thymocytes, and leads to ROR?t-dependent apoptosis. These results extend the action of IL-23 beyond its peripheral effects to a unique role in TCR-mediated negative selection including elimination of natural T regulatory cells in the thymus.

| S-EPMC4136447 | biostudies-literature

TCR-mediated ThPOK induction promotes development of mature (CD24-) gammadelta thymocytes.

Project description:T lymphocytes develop into two major lineages characterized by expression of the alphabeta and gammadelta T cell receptor (TCR) heterodimers. Within each major lineage, further specialization occurs, resulting in distinct subsets that differ in TCR specificity, phenotype and functional attributes. Thus, in the murine thymus, two distinct subsets of mature (CD24-) gammadelta cells have been identified, that is NK1.1+ cells, which are enriched for Vgamma1.1 usage and selectively produce IFNgamma on stimulation, and CCR6+ cells, which are enriched for Vgamma2 usage produce IL17. The upstream signals and transcriptional pathways that promote development of these distinct gammadelta subsets remain relatively poorly understood. Here, we show that the Zn-finger transcription factor ThPOK has a critical function in the development of gammadelta thymocytes. Thus, lack of functional ThPOK causes a marked reduction in the percentage and absolute number of mature gammadelta thymocytes, and a particularly severe reduction of NK1.1+ cells. Conversely, constitutive ThPOK expression leads to a striking increase in mature NK1.1+ gammadelta thymocytes. Further, we show that ThPOK induction in gammadelta thymocytes is induced by strong TCR signals mediated by engagement with antibody or high-affinity endogenous ligands, and that an important ThPOK cis-acting element, the distal regulatory element (DRE), is sufficient for this TCR-dependent induction. These results show that ThPOK expression in gammadelta thymocytes is regulated in part by the strength of TCR signalling, identify ThPOK as an important mediator of gammadelta T cell development/maturation, and lend strong support to the view that development of a significant fraction of gammadelta T cells depends on TCR engagement/signalling.

| S-EPMC2910264 | biostudies-literature

A TCR mechanotransduction signaling loop induces negative selection in the thymus.

Project description:The T cell antigen receptor (TCR) expressed on thymocytes interacts with self-peptide major histocompatibility complex (pMHC) ligands to signal apoptosis or survival. Here, we found that negative-selection ligands induced thymocytes to exert forces on the TCR and the co-receptor CD8 and formed cooperative TCR-pMHC-CD8 trimolecular 'catch bonds', whereas positive-selection ligands induced less sustained thymocyte forces on TCR and CD8 and formed shorter-lived, independent TCR-pMHC and pMHC-CD8 bimolecular 'slip bonds'. Catch bonds were not intrinsic to either the TCR-pMHC or the pMHC-CD8 arm of the trans (cross-junctional) heterodimer but resulted from coupling of the extracellular pMHC-CD8 interaction to the intracellular interaction of CD8 with TCR-CD3 via associated kinases to form a cis (lateral) heterodimer capable of inside-out signaling. We suggest that the coupled trans-cis heterodimeric interactions form a mechanotransduction loop that reinforces negative-selection signaling that is distinct from positive-selection signaling in the thymus.

| S-EPMC6452639 | biostudies-literature

Inhibition of the kinase Csk in thymocytes reveals a requirement for actin remodeling in the initiation of full TCR signaling.

Project description:Signaling via the T cell antigen receptor (TCR) is initiated by Src-family kinases (SFKs). To understand how the kinase Csk, a negative regulator of SFKs, controls the basal state and the initiation of TCR signaling, we generated mice that express a Csk variant sensitive to an analog of the common kinase inhibitor PP1 (Csk(AS)). Inhibition of Csk(AS) in thymocytes, without engagement of the TCR, induced potent activation of SFKs and proximal TCR signaling up to phospholipase C-?1 (PLC-?1). Unexpectedly, increases in inositol phosphates, intracellular calcium and phosphorylation of the kinase Erk were impaired. Altering the actin cytoskeleton pharmacologically or providing costimulation via CD28 'rescued' those defects. Thus, Csk has a critical role in preventing TCR signaling. However, our studies also revealed a requirement for actin remodeling, initiated by costimulation, for full TCR signaling.

| S-EPMC3946925 | biostudies-literature

Human and Murine Clonal CD8+ T Cell Expansions Arise during Tuberculosis Because of TCR Selection.

Project description:The immune system can recognize virtually any antigen, yet T cell responses against several pathogens, including Mycobacterium tuberculosis, are restricted to a limited number of immunodominant epitopes. The host factors that affect immunodominance are incompletely understood. Whether immunodominant epitopes elicit protective CD8+ T cell responses or instead act as decoys to subvert immunity and allow pathogens to establish chronic infection is unknown. Here we show that anatomically distinct human granulomas contain clonally expanded CD8+ T cells with overlapping T cell receptor (TCR) repertoires. Similarly, the murine CD8+ T cell response against M. tuberculosis is dominated by TB10.44-11-specific T cells with extreme TCR? bias. Using a retro genic model of TB10.44-11-specific CD8+ Tcells, we show that TCR dominance can arise because of competition between clonotypes driven by differences in affinity. Finally, we demonstrate that TB10.4-specific CD8+ T cells mediate protection against tuberculosis, which requires interferon-? production and TAP1-dependent antigen presentation in vivo. Our study of how immunodominance, biased TCR repertoires, and protection are inter-related, provides a new way to measure the quality of T cell immunity, which if applied to vaccine evaluation, could enhance our understanding of how to elicit protective T cell immunity.

| S-EPMC4422591 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data