scholarly journals Crosslinking of the T cell-specific accessory molecules CD7 and CD28 modulates T cell adhesion.

1992 ◽  
Vol 175 (2) ◽  
pp. 577-582 ◽  
Author(s):  
Y Shimizu ◽  
G A van Seventer ◽  
E Ennis ◽  
W Newman ◽  
K J Horgan ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
Matrix Protein ◽  
Receptor Expression ◽  
Extracellular Matrix Protein ◽  
Ionophore A23187 ◽  
Potent Inducer ◽  
Accessory Molecules ◽  
T Cell Adhesion

Regulated adhesion enables T cells to migrate through tissue and transiently interact with an endless succession of cells. Monoclonal antibody (mAb) engagement of the CD3/T cell receptor (TCR) complex results in a rapid and transient augmentation of the adhesion function of LFA-1 and VLA integrin molecules on human T cells. We show in this study that mAb crosslinking of the T cell-specific accessory molecules CD7 and CD28, or treatment with the Ca2+ ionophore A23187, results in the rapid induction of integrin-mediated adhesion to three distinct ligands: the extracellular matrix protein fibronectin, and the cell surface molecules ICAM-1 and VCAM-1. Like CD3 crosslinking, increased adhesion via CD7 and CD28 crosslinking appears to involve both protein kinase C (PKC) and cAMP-dependent protein kinases. In contrast, A23187 induction of adhesion is unaffected by PKC inhibitors. CD7 is preferentially expressed on naive T cells and is unique in being a potent inducer of naive T cell adhesion. Enhanced expression/function of adhesion-inducing molecules thus overcomes relative deficits in adhesion receptor expression.

scholarly journals Regulatory role of CD43 leukosialin on integrin-mediated T-cell adhesion to endothelial and extracellular matrix ligands and its polar redistribution to a cellular uropod

Blood ◽  
1995 ◽  
Vol 86 (6) ◽  
pp. 2228-2239 ◽  
Author(s):  
P Sanchez-Mateos ◽  
MR Campanero ◽  
MA del Pozo ◽  
F Sanchez-Madrid
Keyword(s):  
T Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
Cell Surface ◽  
Adhesion Molecule ◽  
Negative Regulator ◽  
Regulatory Role ◽  
Beta 2 ◽  
T Lymphoblasts ◽  
T Cell Adhesion

CD43 is a cell surface-associated mucin that is abundantly expressed by most leukocytes, and that appears to function as a negative regulator of cell surface interactions, providing a repulsive barrier around cells. We have analyzed herein the ability of anti-CD43 monoclonal antibody (MoAb) to upregulate both beta 1 and beta 2 integrin-mediated cell adhesion and to promote redistribution of the CD43 molecule into a cellular uropod. Engagement of CD43 with specific antibodies enhanced the cell adhesion to both 80- and 38-kD fibronectin fragments as well as to the endothelial cell ligands vascular cell adhesion molecule-1 and intercellular adhesion molecule-1, an effect that was mediated through the alpha 5 beta 1, alpha 4 beta 1, and alpha L beta 2 integrins, respectively. This effect on cell adhesion was achieved in Jurkat leukemic T cells by anti-CD43 MoAb alone; however, in T lymphoblasts, the activation of cell adhesion required the concomitant ligation of CD3 with suboptimal doses of anti-CD3 MoAb. Immunofluorescence analysis showed that the engagement of CD43 was accompanied by a differential redistribution of CD43 into a well- defined cytoplasmic projection or uropod, whereas the beta 1 or beta 2 integrins remained uniformly located on the contact area with substrata. This change in the localization of CD43 did not require costimulation and was induced directly by engagement of CD43 in T lymphoblasts. Other stimuli of cell adhesion in the form of cross- linked anti-CD3 MoAb or phorbol esters did not induce uropod formation or CD43 redistribution. In addition, we observed that prolonged co- culture of resting peripheral blood T lymphocytes with endothelial cells, in the absence of anti-CD43 MoAb, induced uropod formation and redistribution of CD43 in T cells. Interestingly, the myosin-disrupting drug butanedione monoxime inhibited the redistribution of CD43 induced by the specific MoAb, whereas the stimulation of cell adhesion induced by engagement of CD43 was preserved in the presence of this drug. These observations indicate that the signaling inducing integrin-mediated cell adhesion by CD43 takes place independently from the receptor redistribution. Altogether, these results indicate that CD43 has a regulatory role on both integrin-mediated T-cell adhesion and cellular morphology.

scholarly journals T cell-activating properties of an anti-Thy-1 monoclonal antibody. Possible analogy to OKT3/Leu-4.

1984 ◽  
Vol 159 (3) ◽  
pp. 716-730 ◽  
Author(s):  
K C Gunter ◽  
T R Malek ◽  
E M Shevach
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
Molecular Complex ◽  
Lymphocyte Activation ◽  
Receptor Expression ◽  
Cell Surface Molecule ◽  
Potent Inducer ◽  
A Cell ◽  
Relationship Of

We have identified a single rat monoclonal antibody, G7, that is a potent inducer of interleukin (IL-2) production from all functioning T cell hybridomas as well as from normal T cells. G7 is also mitogenic for normal T cells and is a very effective inducer of IL-2 receptor expression. On fluorescence-activated cell sorter analysis, G7 recognized a pan-T cell antigen. Immunoprecipitation studies demonstrated that G7 recognized a cell surface molecule of 28-32 kD that appeared to be identical to Thy-1 in coprecipitation studies. In addition, G7 precipitated a protein of 50 kD. The possible relationship of the putative molecular complex identified by G7 on murine cells to the molecular complex identified on human T cells with anti-T3 reagents is discussed. In addition, G7 should prove to be a very useful reagent for studying the early events of lymphocyte activation as well as an inducer of lymphokine-rich supernatants.

scholarly journals Three-Dimensional Model of Sub-Plasmalemmal Ca2+ Microdomains Evoked by the Interplay Between ORAI1 and InsP3 Receptors

2021 ◽  
Vol 12 ◽  
Author(s):  
Diana Gil ◽  
Andreas H. Guse ◽  
Geneviève Dupont
Keyword(s):  
T Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Three Dimensional ◽  
Receptor Activation ◽  
Reaction Diffusion Model ◽  
Activated State ◽  
T Cell Adhesion

Ca2+ signaling plays an essential role in T cell activation, which is a key step to start an adaptive immune response. During the transition from a quiescent to a fully activated state, Ca2+ microdomains characterized by reduced spatial and temporal extents are observed in the junctions between the plasma membrane (PM) and the endoplasmic reticulum (ER). Such Ca2+ responses can also occur in response to T cell adhesion to other cells or extracellular matrix proteins in otherwise unstimulated T cells. These non-TCR/CD3-dependent Ca2+ microdomains rely on d-myo-inositol 1,4,5-trisphosphate (IP3) signaling and subsequent store operated Ca2+ entry (SOCE) via the ORAI/STIM system. The detailed molecular mechanism of adhesion-dependent Ca2+ microdomain formation remains to be fully elucidated. We used mathematical modeling to investigate the spatiotemporal characteristics of T cell Ca2+ microdomains and their molecular regulators. We developed a reaction-diffusion model using COMSOL Multiphysics to describe the evolution of cytosolic and ER Ca2+ concentrations in a three-dimensional ER-PM junction. Equations are based on a previously proposed realistic description of the junction, which is extended to take into account IP3 receptors (IP3R) that are located next to the junction. The first model only considered the ORAI channels and the SERCA pumps. Taking into account the existence of preformed clusters of ORAI1 and STIM2, ORAI1 slightly opens in conditions of a full ER. These simulated Ca2+ microdomains are too small as compared to those observed in unstimulated T cells. When considering the opening of the IP3Rs located near the junction, the local depletion of ER Ca2+ allows for larger Ca2+ fluxes through the ORAI1 channels and hence larger local Ca2+ concentrations. Computational results moreover show that Ca2+ diffusion in the ER has a major impact on the Ca2+ changes in the junction, by affecting the local Ca2+ gradients in the sub-PM ER. Besides pointing out the likely involvement of the spontaneous openings of IP3Rs in the activation of SOCE in conditions of T cell adhesion prior to full activation, the model provides a tool to investigate how Ca2+ microdomains extent and interact in response to T cell receptor activation.

Selective differences in vascular endothelial- vs. airway epithelial-T cell adhesion mechanisms

1994 ◽  
Vol 267 (4) ◽  
pp. L422-L432 ◽  
Author(s):  
S. Nakajima ◽  
D. C. Look ◽  
W. T. Roswit ◽  
M. J. Bragdon ◽  
M. J. Holtzman
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Endothelial Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
Epithelial Cell ◽  
Vascular Endothelial ◽  
Airway Epithelial ◽  
Beta 2 ◽  
T Cell Adhesion

The basis for T cell adhesion to airway epithelial and vascular endothelial cells was studied using a quantitative flow cytometry-based assay that avoids extensive leukocyte purification and labeling. Compared with standard cell-labeling methods, the flow cytometry-based assay yielded a lower level of constitutive T cell adhesion, despite a similar level of stimulated adhesion (after T cell activation with phorbol dibutyrate) using endothelial or epithelial cell monolayers. Endothelial T cell adhesion was further increased by monolayer treatment with tumor necrosis factor-alpha (less so with interleukin-1 beta and least with interferon-gamma), whereas epithelial T cell adhesion was most sensitive to interferon-gamma. Cytokine stimulation of adhesion was invariably concentration dependent and closely matched to the cellular levels of intracellular adhesion molecule-1 (ICAM-1). Accordingly, stimulated T cell adhesion was markedly inhibited by anti-ICAM-1 or anti-beta 2-integrin antibody (95-97% inhibition for epithelial cells and 57-67% inhibition for endothelial cells) directed against ICAM-1 interaction with lymphocyte function-associated antigen-1 (LFA-1; alpha L beta 2-integrin). Residual endothelial T cell adhesion that correlated with endothelial vascular cell adhesion molecule-1 (VCAM-1) levels was blocked by an anti-alpha 4-integrin antibody directed against VCAM-1 interaction with very late activation antigen-4 (VLA-4; alpha 4 beta 1-integrin). The results suggest that 1) peripheral blood T cells without exogenous activation exhibit little LFA-1- or VLA-4-dependent adherence except to endothelial or epithelial cells expressing high levels of ICAM-1 and/or VCAM-1; and 2) differences in endothelial vs. epithelial cell mechanisms to bind activated and unactivated T cells (e.g., dependence on a mixed- vs. a single-ligand system and distinct cytokine-responsiveness of ligand levels) may help to coordinate T cell traffic to epithelial barriers.

scholarly journals Salicylates Inhibit Adhesion and Transmigration of T Lymphocytes by Preventing Integrin Activation Induced by Contact With Endothelial Cells

Blood ◽  
1998 ◽  
Vol 92 (7) ◽  
pp. 2389-2398 ◽  
Author(s):  
Roberto Gerli ◽  
Cristina Paolucci ◽  
Paolo Gresele ◽  
Onelia Bistoni ◽  
Stefano Fiorucci ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
T Lymphocytes ◽  
Cell Function ◽  
Static System ◽  
Functional Changes ◽  
And Migration ◽  
T Cell Adhesion

The inhibition of cyclooxygenase does not fully account for the spectrum of activities of nonsteroidal antiinflammatory drugs. It is evident, indeed, that regulation of inflammatory cell function may contribute in explaining some of the effects of these drugs. Tissue recruitment of T cells plays a key role in the development of chronic inflammation. Therefore, the effects of salicylates on T-cell adhesion to and migration through endothelial cell monolayers on collagen were analyzed in an in vitro static system. Aspirin and sodium salicylate reduced the ability of unstimulated T cells to adhere to and transmigrate through cytokine-activated endothelium. Although salicylates did not modify the expression of integrins on T cells, they blunted the increased adherence induced by the anti-β2monoclonal antibody (MoAb) KIM127 and prevented the appearance of an activation-dependent epitope of the CD11/CD18 complex, recognized by the MoAb 24, induced by contact with endothelial cells. Salicylates also induced an increase of intracellular calcium ([Ca2+]i) and activation of protein kinase C (PKC) in T cells, but not cell proliferation and interleukin (IL)-2 synthesis. The reduction of T-cell adhesiveness appears to be dependent on the increase in[Ca2+]i levels, as it could be reversed by blocking Ca2+ influx, but not by inhibiting PKC. Moreover, ionomycin at concentrations giving an increase in [Ca2+]i similar to that triggered by aspirin, strictly reproduced the T-cell phenotypic and functional changes induced by salicylates. Aspirin reduced T-cell adhesion and migration also ex vivo after infusion to healthy volunteers. These data suggest that the antiinflammatory activity of salicylates may be due, at least in part, to an interference with the integrin-mediated binding of resting T lymphocytes to activated endothelium with consequent reduction of a specific T-cell recruitment into inflammatory sites.

scholarly journals Four molecular pathways of T cell adhesion to endothelial cells: roles of LFA-1, VCAM-1, and ELAM-1 and changes in pathway hierarchy under different activation conditions.

1991 ◽  
Vol 113 (5) ◽  
pp. 1203-1212 ◽  
Author(s):  
Y Shimizu ◽  
W Newman ◽  
T V Gopal ◽  
K J Horgan ◽  
N Graber ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
T Cell Subsets ◽  
Molecular Pathways ◽  
T Cell Adhesion

T cell adhesion to endothelium is critical to lymphocyte recirculation and influx into sites of inflammation. We have systematically analyzed the role of four receptor/ligand interactions that mediate adhesion of peripheral human CD4+ T cells to cultured human umbilical vein endothelial cells (HUVEC): T cell LFA-1 binding to ICAM-1 and an alternative ligand ("ICAM-X"), T cell VLA-4 binding to VCAM-1, and T cell binding to ELAM-1. Contributions of these four pathways depend on the activation state of both the T cell and HUVEC, and the differentiation state of the T cell. ELAM-1 plays a significant role in mediating adhesion of resting CD4+ T cells to activated HUVEC. LFA-1 adhesion dominates with PMA-activated T cells but the strength and predominant LFA-1 ligand is determined by the activation state of the HUVEC; while ICAM-1 is the dominant ligand on IL-1-induced HUVEC, "ICAM-X" dominates binding to uninduced HUVEC. Adhesion via VLA-4 depends on induction of its ligand VCAM-1 on activated HUVEC; PMA activation of T cells augments VLA-4-mediated adhesion, both in the model of T/HUVEC binding and in a simplified model of T cell adhesion to VCAM-1-transfected L cells. Unlike LFA-1 and VLA-4, ELAM-1-mediated adhesion is not increased by T cell activation. Differential expression of adhesion molecules on CD4+ T cell subsets understood to be naive and memory cells also regulates T/HUVEC adhesion. Naive T cell adhesion to HUVEC is mediated predominantly by LFA-1 with little or no involvement of the VLA-4 and ELAM-1 pathways. In contrast, memory T cells bind better to HUVEC and utilize all four pathways. These studies demonstrate that there are at least four molecular pathways mediating T/HUVEC adhesion and that the dominance/hierarchy of these pathways varies dramatically with the activation state of the interacting cells and the differentiation state of the T cell.

scholarly journals HLA-A2.1-restricted ECM1-derived epitope LA through DC cross-activation priming CD8+ T and NK cells: a novel therapeutic tumour vaccine

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Zhaojin Yu ◽  
Wensi Liu ◽  
Ying He ◽  
Mingli Sun ◽  
Jiankun Yu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Matrix Protein ◽  
Extracellular Matrix Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Death Pathway ◽  
Tumour Vaccine ◽  
Hla A2.1 ◽  
Novel Therapeutic

Abstract Background CD8+ T cell-mediated adaptive cellular immunity and natural killer (NK) cell-mediated innate immunity both play important roles in tumour immunity. This study aimed to develop therapeutic tumour vaccines based on double-activation of CD8+ T and NK cells. Methods The immune Epitope database, Molecular Operating Environment software, and enzyme-linked immunosorbent assay were used for epitope identification. Flow cytometry, confocal microscopy, UPLC-QTOF-MS, and RNA-seq were utilized for evaluating immunity of PBMC-derived DCs, CD8+ T or NK cells and related pathways. HLA-A2.1 transgenic mice combined with immunologically reconstituted tumour-bearing mice were used to examine the antitumour effect and safety of epitope vaccines. Results We identified novel HLA-A2.1-restricted extracellular matrix protein 1(ECM1)-derived immunodominant epitopes in which LA induced a potent immune response. We also found that LA-loaded DCs upregulated the frequency of CD3+/CD8+ T cells, CD45RO+/CD69+ activated memory T cells, and CD3−/CD16+/CD56+ NK cells. We demonstrated cytotoxic granule release of LA/DC-CTLs or LA/DC-NK cells and cytotoxicity against tumour cells and microtissue blocks via the predominant IFN-γ/perforin/granzyme B cell death pathway. Further investigating the mechanism of LA-mediated CD8+ T activation, we found that LA could be internalized into DCs through phagocytosis and then formed a LA-MHC-I complex presented onto the DC surface for recognition of the T cell receptor to upregulate Zap70 phosphorylation levels to further activate CD8+ T cells by DC-CTL interactions. In addition, LA-mediated DC-NK crosstalk through stimulation of the TLR4-p38 MAPK pathway increased MICA/B expression on DCs to interact with NKG2D for NK activation. Promisingly, LA could activate CD8+ T cells and NK cells simultaneously via interacting with DCs to suppress tumours in vivo. Moreover, the safety of LA was confirmed. Conclusions LA-induced immune antitumour activity through DC cross-activation with CD8+ T and NK cells, which demonstrated proof-of-concept evidence for the capability and safety of a novel therapeutic tumour vaccine.

scholarly journals Coexpression and functional cooperation of CTLA-4 and CD28 on activated T lymphocytes.

1992 ◽  
Vol 176 (6) ◽  
pp. 1595-1604 ◽  
Author(s):  
P S Linsley ◽  
J L Greene ◽  
P Tan ◽  
J Bradshaw ◽  
J A Ledbetter ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
T Lymphocytes ◽  
T Cell Subsets ◽  
T Cell Proliferation ◽  
Activated T Cells ◽  
Activated T Lymphocytes ◽  
T Cell Adhesion

T cell costimulation by molecules on the antigen presenting cell (APC) is required for optimal T cell proliferation. The B7 molecule on APC binds the T lymphocyte receptor CD28, triggering increased interleukin 2 (IL-2) production and subsequent T cell proliferation. CTLA-4 is a predicted T cell membrane receptor homologous to CD28, which also binds the B7 counter receptor, but whose distribution and function are unknown. Here we have developed monoclonal antibodies (mAbs) specific for CTLA-4 and have investigated these questions. mAbs were produced that bound CTLA-4 but not CD28, and that blocked binding of CTLA-4 to B7. CTLA-4 expression as measured by these mAbs was virtually undetectable on resting T cells, but was increased several hundred-fold during T cell activation. On activated lymphocytes, CTLA-4 was expressed equally on CD4+ and CD8+ T cell subsets and was coexpressed with CD25, CD28, and CD45RO. CTLA-4 expression was lower than that of CD28, reaching a maximum of approximately 1/30-50 the level of CD28. Despite its lower expression, CTLA-4 was responsible for much of the B7 binding by large activated T cells. Anti-CTLA-4 mAb 11D4 and anti-CD28 mAb 9.3 acted cooperatively to inhibit T cell adhesion to B7, and to block T cell proliferation in primary mixed lymphocyte culture. When coimmobilized with anti T cell receptor (TCR) mAb, anti-CTLA-4 mAbs were less effective than anti-CD28 mAb 9.3 at costimulating proliferation of resting or activated T cells. However, coimmobilized combinations of anti-CD28 and anti-CTLA-4 were synergistic in their ability to augment anti-TCR-induced proliferation of preactivated CD4+ T cells. These results indicate that CTLA-4 is coexpressed with CD28 on activated T lymphocytes and cooperatively regulates T cell adhesion and activation by B7.

scholarly journals Rap1 up-regulation and activation on plasma membrane regulates T cell adhesion

2004 ◽  
Vol 164 (3) ◽  
pp. 461-470 ◽  
Author(s):  
Trever G. Bivona ◽  
Heidi H. Wiener ◽  
Ian M. Ahearn ◽  
Joseph Silletti ◽  
Vi K. Chiu ◽  
...  
Keyword(s):  
T Cells ◽  
Plasma Membrane ◽  
Cell Adhesion ◽  
T Cell ◽  
Subcellular Localization ◽  
Fluorescent Probe ◽  
Living Cells ◽  
Gtp Binding ◽  
Biological Differences ◽  
T Cell Adhesion

Rap1 and Ras are closely related GTPases that share some effectors but have distinct functions. We studied the subcellular localization of Rap1 and its sites of activation in living cells. Both GFP-tagged Rap1 and endogenous Rap1 were localized to the plasma membrane (PM) and endosomes. The PM association of GFP-Rap1 was dependent on GTP binding, and GFP-Rap1 was rapidly up-regulated on this compartment in response to mitogens, a process blocked by inhibitors of endosome recycling. A novel fluorescent probe for GTP-bound Rap1 revealed that this GTPase was transiently activated only on the PM of both fibroblasts and T cells. Activation on the PM was blocked by inhibitors of endosome recycling. Moreover, inhibition of endosome recycling blocked the ability of Rap1 to promote integrin-mediated adhesion of T cells. Thus, unlike Ras, the membrane localizations of Rap1 are dynamically regulated, and the PM is the principle platform from which Rap1 signaling emanates. These observations may explain some of the biological differences between these GTPases.

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