scholarly journals Intestinal intraepithelial lymphocytes include precursors committed to the T cell receptor αβ lineage

1998 ◽  
Vol 95 (16) ◽  
pp. 9459-9464 ◽  
Author(s):  
Stephanie T. Page ◽  
Lisa Y. Bogatzki ◽  
Jessica A. Hamerman ◽  
Claire H. Sweenie ◽  
Philip J. Hogarth ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Nude Mice ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Intraepithelial Lymphocytes ◽  
Tcr Signaling ◽  
Intestinal Intraepithelial Lymphocytes ◽  
Cell Commitment

The majority of T cells develop in the thymus and exhibit well characterized phenotypic changes associated with their maturation. Previous analysis of intestinal intraepithelial lymphocytes (IEL) from nude mice and a variety of experimentally manipulated models led to the view that at least a portion of these cells represent a distinct T cell population that matures extrathymically. The IEL that are postulated to mature within the intestine include both T cell receptor (TCR) αβ- and γδ-bearing subpopulations. They can be distinguished from conventional thymically derived T cells in that they express an unusual coreceptor, a CD8α homodimer. In addition, they can utilize the Fc receptor γ-chain in place of the CD3-associated ζ-chain for TCR signaling and their maturation depends on the interleukin 2 receptor β-chain. Moreover, TCRαβ+CD8αα+ IEL are not subject to conventional thymic selection processes. To determine whether CD3−CD8αα+ IEL represent precursors of T cells developing extrathymically, we examined IEL from knockout mice lacking the recombination activating gene-1 (rag-1), CD3ɛ, or both Lck and Fyn, in which thymic T cell development is arrested. CD3−CD8αα+CD16+ IEL from all three mutant strains, as well as from nude mice, included cells that express pre-TCRα transcripts, a marker of T cell commitment. These IEL from lck−/−fyn−/− animals exhibited TCR β-gene rearrangement. However, CD3−CD8αα+CD16+ IEL from ɛ-deficient mice had not undergone Dβ-Jβ joining, despite normal rearrangement at the TCRβ locus in thymocytes from these animals. These results revealed another distinction between thymocytes and IEL, and suggested an unexpectedly early role for CD3ɛ in IEL maturation.

scholarly journals T Cell Receptor–initiated Calcium Release Is Uncoupled from Capacitative Calcium Entry in Itk-deficient T Cells

1998 ◽  
Vol 187 (10) ◽  
pp. 1721-1727 ◽  
Author(s):  
Karen-Qianye Liu ◽  
Stephen C. Bunnell ◽  
Christine B. Gurniak ◽  
Leslie J. Berg
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Calcium Release ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Calcium Entry ◽  
Tcr Signaling ◽  
Store Depletion ◽  
High Concentrations

Itk, a Tec family tyrosine kinase, plays an important but as yet undefined role in T cell receptor (TCR) signaling. Here we show that T cells from Itk-deficient mice have a TCR-proximal signaling defect, resulting in defective interleukin 2 secretion. Upon TCR stimulation, Itk−/− T cells release normal amounts of calcium from intracellular stores, but fail to open plasma membrane calcium channels. Since thapsigargin-induced store depletion triggers normal calcium entry in Itk−/− T cells, an impaired biochemical link between store depletion and channel opening is unlikely to be responsible for this defect. Biochemical studies indicate that TCR-induced inositol 1,4,5 tris-phosphate (IP3) generation and phospholipase C γ1 tyrosine phosphorylation are substantially reduced in Itk−/− T cells. In contrast, TCR-ζ and ZAP-70 are phosphorylated normally, suggesting that Itk functions downstream of, or in parallel to, ZAP-70 to facilitate TCR-induced IP3 production. These findings support a model in which quantitative differences in cytosolic IP3 trigger distinct responses, and in which only high concentrations of IP3 trigger the influx of extracellular calcium.

Ig alpha and Ig beta are functionally homologous to the signaling proteins of the T-cell receptor

1994 ◽  
Vol 14 (2) ◽  
pp. 1095-1103
Author(s):  
A L Burkhardt ◽  
T Costa ◽  
Z Misulovin ◽  
B Stealy ◽  
J B Bolen ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Receptor ◽  
Interleukin 2 ◽  
Antigen Receptor ◽  
Cell Receptor ◽  
Antigen Receptors ◽  
Cell Antigen

Signal transduction by antigen receptors and some Fc receptors requires the activation of a family of receptor-associated transmembrane accessory proteins. One common feature of the cytoplasmic domains of these accessory molecules is the presence is at least two YXXA repeats that are potential sites for interaction with Src homology 2 domain-containing proteins. However, the degree of similarity between the different receptor-associated proteins varies from that of T-cell receptor (TCR) zeta and Fc receptor RIIIA gamma chains, which are homologous, to the distantly related Ig alpha and Ig beta proteins of the B-cell antigen receptor. To determine whether T- and B-cell antigen receptors are in fact functionally homologous, we have studied signal transduction by chimeric immunoglobulins bearing the Ig alpha or Ig beta cytoplasmic domain. We found that Ig alpha and Ig beta cytoplasmic domains were able to activate Ca2+ flux, interleukin-2 secretion, and phosphorylation of the same group of cellular substrates as the TCR in transfected T cells. Chimeric proteins were then used to examine the minimal requirements for activation of the Fyn, Lck, and ZAP kinases in T cells. Both Ig alpha and Ig beta were able to trigger Fyn, Lck, and ZAP directly without involvement of TCR components. Cytoplasmic tyrosine residues in Ig beta were required for recruitment and activation of ZAP-70, but these amino acids were not essential for the activation of Fyn and Lck. We conclude that Fyn and Lck are able to recognize a clustered nonphosphorylated immune recognition receptor, but activation of these kinases is not sufficient to induce cellular responses such as Ca2+ flux and interleukin-2 secretion. In addition, the molecular structures involved in antigen receptor signaling pathways are conserved between T and B cells.

T-cell proliferation involving the CD28 pathway is associated with cyclosporine-resistant interleukin 2 gene expression

1987 ◽  
Vol 7 (12) ◽  
pp. 4472-4481
Author(s):  
C H June ◽  
J A Ledbetter ◽  
M M Gillespie ◽  
T Lindsten ◽  
C B Thompson
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
T Cell Proliferation ◽  
Cd28 Molecule ◽  
T Cell Stimulation ◽  
Protein Kinase C Activation

CD28 is a homodimeric glycoprotein expressed on the surface of a major subset of human T cells that has recently been identified as a member of the immunoglobulin supergene family. The binding of monoclonal antibodies to the CD28 antigen on purified T cells does not result in proliferation; however, previous studies have shown that the combination of CD28 stimulation and protein kinase C activation by phorbol myristate acetate (PMA) results in T-cell proliferation that is independent of both accessory cells and activation of the T-cell receptor-CD3 complex. In the present study, effects of stimulation by anti-CD28 on cell cycle progression and on the interleukin 2 (IL-2) and IL-2 receptor system have been investigated on primary cultures of purified peripheral-blood CD28+ T cells. There was no measurable effect on cell size or on DNA synthesis after stimulation of resting (G0) cells by CD28 alone. After 3 h of activation of T cells by PMA alone, a slight (8%) increase in cell volume occurred that did not progress to DNA synthesis. In contrast, T-cell stimulation by CD28 in combination with PMA resulted in a progressive increase in cell volume in approximately 100% of cells at 12 to 14 h after stimulation. Northern blot (RNA blot) analysis revealed that CD28 stimulation alone failed to cause expression of the alpha chain of the IL-2 receptor or of IL-2 mRNA, and in accord with previous studies, stimulation by PMA alone resulted in the accumulation of IL-2 receptor transcripts but no detectable IL-2 mRNA. In contrast, T-cell stimulation by the combination of CD28 and PMA resulted in the appearance of IL-2 transcripts and enhanced expression of IL-2 receptor mRNA. Functional studies revealed that the proliferation induced by CD28 and PMA stimulation was entirely resistant to cyclosporine, in contrast to T-cell activation induced by the CD3-T-cell receptor complex. Cyclosporine was found not to affect the accumulation of IL-2 mRNA after CD28 plus PMA stimulation, although there was no detectable IL-2 mRNA after stimulation by CD3 in the presence of the drug. Furthermore, stimulation by CD28 in combination with immobilized CD3 antibodies caused a striking enhancement of IL-2 mRNA expression that was, in part, resistant to the effects of cyclosporine. These studies indicate that the CD28 molecule synergizes with protein kinase C activation to induce IL-2 gene expression and demonstrate that stimulation by the CD28 pathway can cause vigorous T-cell proliferation even in the presence of cyclosporine and that cyclosporine does not prevent transcription of 16-2 mRNA, as has been suggested previously. Moreover, these findings suggest that a potential role for the CD28 molecule in vivo may be to augment IL-2 production after stimulation of the CD3-T-cell receptor molecular complex and thereby to amplify an antigen-specific immune response. Finally, these results provide further evidence that the CD28 molecule triggers T-cell proliferation in a manner that differs biochemically from CD3-T-cell receptor-induced proliferation.

scholarly journals Evidence for extrathymic generation of intermediate T cell receptor cells in the liver revealed in thymectomized, irradiated mice subjected to bone marrow transplantation.

1995 ◽  
Vol 182 (3) ◽  
pp. 759-767 ◽  
Author(s):  
K Sato ◽  
K Ohtsuka ◽  
K Hasegawa ◽  
S Yamagiwa ◽  
H Watanabe ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Bone Marrow Transplantation ◽  
T Cell ◽  
T Cell Receptor ◽  
Marrow Transplantation ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Phenotypic Characterization ◽  
Receptor Cells

In addition to the major intrathymic pathway of T cell differentiation, extrathymic pathways of such differentiation have been shown to exist in the liver and intestine. In particular, hepatic T cells of T cell receptors or CD3 of intermediate levels (i.e., intermediate T cell receptor cells) always contain self-reactive clones and sometimes appear at other sites, including the target tissues in autoimmune diseases and the tumor sites in malignancies. To prove their extrathymic origin and self reactivity, in this study we used thymectomized, irradiated (B6 x C3H/He) F1 mice subjected to transplantation of bone marrow cells of B6 mice. It was clearly demonstrated that all T cells generated under athymic conditions in the peripheral immune organs are intermediate CD3 cells. In the case of nonthymectomized irradiated mice, not only intermediate CD3 cells but also high CD3 cells were generated. Phenotypic characterization showed that newly generated intermediate CD3 cells were unique (e.g., interleukin 2 receptor alpha-/beta+ and CD44+ L-selectin-) and were, therefore, distinguishable from thymus-derived T cells. The precursor cells of intermediate CD3 cells in the bone marrow were Thy-1+ CD3-. The extrathymic generation of intermediate CD3 cells was confirmed in other combinations of bone marrow transplantation, C3H --> C3H and B10.Thy1.1 --> B6.Thy1.2. The generated intermediate CD3 cells in the liver contained high levels of self-reactive clones estimated by anti-V beta monoclonal antibodies in conjunction with the endogenous superantigen minor lymphocyte-stimulating system, especially the combination of B6 --> (B6 x C3H/He) (graft-versus-host-situation).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Loss of tonic T-cell receptor signals alters the generation but not the persistence of CD8+ memory T cells

Blood ◽  
2010 ◽  
Vol 116 (25) ◽  
pp. 5560-5570 ◽  
Author(s):  
Karla R. Wiehagen ◽  
Evann Corbo ◽  
Michelle Schmidt ◽  
Haina Shin ◽  
E. John Wherry ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Lymphocytic Choriomeningitis ◽  
Sh2 Domain ◽  
Normal Numbers ◽  
Tcr Signaling ◽  
Tcr Signals

Abstract The requirements for tonic T-cell receptor (TCR) signaling in CD8+ memory T-cell generation and homeostasis are poorly defined. The SRC homology 2 (SH2)-domain–containing leukocyte protein of 76 kDa (SLP-76) is critical for proximal TCR-generated signaling. We used temporally mediated deletion of SLP-76 to interrupt tonic and activating TCR signals after clearance of the lymphocytic choriomeningitis virus (LCMV). SLP-76–dependent signals are required during the contraction phase of the immune response for the normal generation of CD8 memory precursor cells. Conversely, LCMV-specific memory CD8 T cells generated in the presence of SLP-76 and then acutely deprived of TCR-mediated signals persist in vivo in normal numbers for more than 40 weeks. Tonic TCR signals are not required for the transition of the memory pool toward a central memory phenotype, but the absence of SLP-76 during memory homeostasis substantially alters the kinetics. Our data are consistent with a model in which tonic TCR signals are required at multiple stages of differentiation, but are dispensable for memory CD8 T-cell persistence.

scholarly journals Fyn-Binding Protein (Fyb)/Slp-76–Associated Protein (Slap), Ena/Vasodilator-Stimulated Phosphoprotein (Vasp) Proteins and the Arp2/3 Complex Link T Cell Receptor (Tcr) Signaling to the Actin Cytoskeleton

2000 ◽  
Vol 149 (1) ◽  
pp. 181-194 ◽  
Author(s):  
Matthias Krause ◽  
Antonio S. Sechi ◽  
Marlies Konradt ◽  
David Monner ◽  
Frank B. Gertler ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Actin Cytoskeleton ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Signaling ◽  
Tcr Signaling ◽  
Activated T Cells ◽  
Antigen Presenting ◽  
Syndrome Protein

T cell receptor (TCR)-driven activation of helper T cells induces a rapid polarization of their cytoskeleton towards bound antigen presenting cells (APCs). We have identified the Fyn- and SLP-76–associated protein Fyb/SLAP as a new ligand for Ena/ vasodilator-stimulated phosphoprotein (VASP) homology 1 (EVH1) domains. Upon TCR engagement, Fyb/SLAP localizes at the interface between T cells and anti-CD3–coated beads, where Evl, a member of the Ena/VASP family, Wiskott-Aldrich syndrome protein (WASP) and the Arp2/3 complex are also found. In addition, Fyb/SLAP is restricted to lamellipodia of spreading platelets. In activated T cells, Fyb/SLAP associates with Ena/VASP family proteins and is present within biochemical complexes containing WASP, Nck, and SLP-76. Inhibition of binding between Fyb/SLAP and Ena/VASP proteins or WASP and the Arp2/3 complex impairs TCR-dependent actin rearrangement, suggesting that these interactions play a key role in linking T cell signaling to remodeling of the actin cytoskeleton.

scholarly journals Qa-2–Dependent Selection of Cd8α/α T Cell Receptor α/β1 Cells in Murine Intestinal Intraepithelial Lymphocytes

2001 ◽  
Vol 193 (3) ◽  
pp. 413-414
Author(s):  
Gobardhan Das ◽  
Dina S. Gould ◽  
Mathew M. Augustine ◽  
Gladis Fragoso ◽  
Edda Sciutto ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Intraepithelial Lymphocytes ◽  
Intestinal Intraepithelial Lymphocytes ◽  
Selection Of

scholarly journals Leukocyte-associated immunoglobulin-like receptor 1 inhibits T-cell signaling by decreasing protein phosphorylation in the T-cell signaling pathway

2020 ◽  
Vol 295 (8) ◽  
pp. 2239-2247 ◽  
Author(s):  
Jeoung-Eun Park ◽  
David D. Brand ◽  
Edward F. Rosloniec ◽  
Ae-Kyung Yi ◽  
John M. Stuart ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tyrosine Kinase ◽  
Cell Signaling ◽  
Signaling Pathway ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Signaling ◽  
Tcr Signaling ◽  
Cell Signaling Pathway

Multiple observations implicate T-cell dysregulation as a central event in the pathogenesis of rheumatoid arthritis. Here, we investigated mechanisms for suppressing T-cell activation via the inhibitory receptor leukocyte-associated immunoglobulin-like receptor 1 (LAIR-1). To determine how LAIR-1 affects T-cell receptor (TCR) signaling, we compared 1) T cells from LAIR-1–sufficient and –deficient mice, 2) Jurkat cells expressing either LAIR-1 mutants or C-terminal Src kinase (CSK) mutants, and 3) T cells from mice that contain a CSK transgene susceptible to chemical inhibition. Our results indicated that LAIR-1 engagement by collagen or by complement C1q (C1Q, which contains a collagen-like domain) inhibits TCR signaling by decreasing the phosphorylation of key components in the canonical T-cell signaling pathway, including LCK proto-oncogene SRC family tyrosine kinase (LCK), LYN proto-oncogene SRC family tyrosine kinase (LYN), ζ chain of T-cell receptor–associated protein kinase 70 (ZAP-70), and three mitogen-activated protein kinases (extracellular signal–regulated kinase, c-Jun N-terminal kinase 1/2, and p38). The intracellular region of LAIR-1 contains two immunoreceptor tyrosine-based inhibition motifs that are both phosphorylated by LAIR-1 activation, and immunoprecipitation experiments revealed that Tyr-251 in LAIR-1 binds CSK. Using CRISPR/Cas9-mediated genome editing, we demonstrate that CSK is essential for the LAIR-1–induced inhibition of the human TCR signal transduction. T cells from mice that expressed a PP1 analog–sensitive form of CSK (CskAS) corroborated these findings, and we also found that Tyr-251 is critical for LAIR-1's inhibitory function. We propose that LAIR-1 activation may be a strategy for controlling inflammation and may offer a potential therapeutic approach for managing autoimmune diseases.

Sign in / Sign up

Export Citation Format

Share Document