scholarly journals A talin-dependent LFA-1 focal zone is formed by rapidly migrating T lymphocytes

2005 ◽  
Vol 170 (1) ◽  
pp. 141-151 ◽  
Author(s):  
Andrew Smith ◽  
Yolanda R. Carrasco ◽  
Paula Stanley ◽  
Nelly Kieffer ◽  
Facundo D. Batista ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
T Lymphocytes ◽  
Focal Adhesions ◽  
Cell Types ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Intercellular Adhesion Molecule 1 ◽  
The Stability ◽  
Focal Zone ◽  
Cell Zone

Cells such as fibroblasts and endothelial cells migrate through the coordinated responses of discrete integrin-containing focal adhesions and complexes. In contrast, little is known about the organization of integrins on the highly motile T lymphocyte. We have investigated the distribution, activity, and cytoskeletal linkage of the integrin lymphocyte function associated antigen-1 (LFA-1) on human T lymphocytes migrating on endothelial cells and on ligand intercellular adhesion molecule-1 (ICAM-1). The pattern of total LFA-1 varies from low expression in the lamellipodia to high expression in the uropod. However, high affinity, clustered LFA-1 is restricted to a mid-cell zone that remains stable over time and over a range of ICAM-1 densities. Talin is essential for the stability and formation of the LFA-1 zone. Disruption of the talin–integrin link leads to loss of zone integrity and a substantial decrease in speed of migration on ICAM-1. This adhesive structure, which differs from the previously described integrin-containing attachments displayed by many other cell types, we have termed the “focal zone.”

Abstract 447: Ac-SDKP Suppresses TNFα-induced ICAM-1 Expression In Endothelial Cells Via Inhibition Of IκB Kinase And NF-κB Activation

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Liping Zhu ◽  
Xiao-Ping Yang ◽  
Pablo Nakagawa ◽  
Nour-Eddine Rhaleb ◽  
Pamela Harding ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Types ◽  
Intercellular Adhesion Molecule ◽  
Intercellular Adhesion Molecule 1 ◽  
Human Coronary Artery ◽  
Mobility Shift ◽  
Autoimmune Myocarditis ◽  
Iκb Kinase ◽  
Subsequent Degradation ◽  
Mobility Shift Assay

N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a naturally occurring tetrapeptide that prevents inflammation and fibrosis in hypertension and other cardiovascular diseases. We previously showed that Ac-SDKP decreased transcription factor NF-κB activation in angiotensin II-induced hypertension and also reduced intercellular adhesion molecule-1 (ICAM-1) expression in an experimental autoimmune myocarditis and hypertension animal model. However, the mechanisms by which Ac-SDKP down-regulated ICAM-1 expression are unclear. TNFα is a proinflammatory cytokine that induces ICAM-1 expression on different cell types. We hypothesized that Ac-SDKP suppresses TNFα-induced ICAM-1 via inhibition of IκB kinase (IKK) and subsequently by blockade of NF-κB activation. Human coronary artery endothelial cells were treated with Ac-SDKP or vehicle and then stimulated with TNFα (0.5 ng/ml). ICAM-1 protein expression and phosphorylation of IKK (p-IKK), inhibitory κB (p-IκB), p38 (p-p38) and ERK (p-ERK) were measured by Western Blot. Activation of NF-κB was determined by electrophoretic mobility shift assay (EMSA). ICAM-1 expression was virtually undetectable under basal conditions, but greatly increased by TNFα. Ac-SDKP dose-dependently suppressed TNFα-induced ICAM-1 expression (set at a value of 1.0 arbitrary units, AU) to 0.67±0.13 (p<0.05), 0.51±0.12 (p<0.01) and 0.39±0.09 AU (p<0.01) at 0.1 nM, 1 nM and 10 nM, respectively. In addition, Ac-SDKP (10 nM) inhibited TNFα-induced p-IKK from 1.0 to 0.71±0.02 AU (p<0.01). Ac-SDKP also inhibited TNFα-induced IKKβ expression from 1.0 to 0.64±0.12 AU (p<0.05), without affecting IKKα expression. Furthermore, Ac-SDKP inhibited TNFα-induced p-IκB from 1.0 to 0.54±0.03 AU (p<0.01). EMSA results showed that Ac-SDKP inhibited TNFα-mediated activation of NF-κB, which was 0.63±0.04-fold of TNFα-treated cells. However, Ac-SDKP had no effect on TNFα-induced p-p38 and p-ERK. Thus, we conclude that Ac-SDKP inhibits TNFα-induced IKK and subsequent degradation of IκB, thereby preventing NF-κB activation and ICAM-1 expression. These inhibitory effects are independent of p38 and ERK.

The integrin LFA-1 signals through ZAP-70 to regulate expression of high-affinity LFA-1 on T lymphocytes

Blood ◽  
2011 ◽  
Vol 117 (12) ◽  
pp. 3331-3342 ◽  
Author(s):  
Rachel Evans ◽  
Annemarie C. Lellouch ◽  
Lena Svensson ◽  
Alison McDowall ◽  
Nancy Hogg
Keyword(s):  
T Lymphocytes ◽  
T Lymphocyte ◽  
Tyrosine Kinases ◽  
Close Contact ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Intercellular Adhesion Molecule 1 ◽  
Lymphocyte Migration ◽  
High Affinity ◽  
And Migration

Abstract The integrin lymphocyte function-associated antigen 1 (LFA-1) controls many functions of T lymphocytes and is particularly essential during lymphocyte migration from blood into tissues. LFA-1 is considered to initiate “outside-in” signaling when bound to ligand intercellular adhesion molecule 1 (ICAM-1), but little is known about the proteins involved or where in the cell such LFA-1–mediated signaling might be operating. Here we show that LFA-1 is constitutively associated with the protein tyrosine kinases Lck and zeta chain–associated protein of 70 kDa (ZAP-70). When LFA-1 binds ICAM-1, both kinases become phosphorylated and the consequence of kinase activation is the conversion of intermediate- to high-affinity LFA-1 and an increase in close contact with ICAM-1. In the polarized T lymphocyte, phospho-ZAP-70 is concentrated within a region of high-affinity LFA-1 that includes talin and encompasses the lamella/lamellipodial interface as well as further back in the cell. Deficiency of ZAP-70 through inhibition or knockdown in T lymphocytes decreases the speed of migration on ICAM-1, as well as reducing firm adhesion under shear-flow conditions. Through its control of high-affinity LFA-1, the LFA-1/Lck/ZAP-70 complex is in position to initiate the rapid adhesion strengthening and migration necessary for T-lymphocyte responses when stimulated vasculature is encountered at sites of infection or injury.

scholarly journals Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecule-1 (ICAM-1) is one of at least three mechanisms for lymphocyte adhesion to cultured endothelial cells.

1988 ◽  
Vol 107 (1) ◽  
pp. 321-331 ◽  
Author(s):  
M L Dustin ◽  
T A Springer
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Adhesion Molecule ◽  
Umbilical Vein ◽  
Peripheral Blood Lymphocytes ◽  
Intercellular Adhesion ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Intercellular Adhesion Molecule 1 ◽  
Lymphocyte Adhesion

Intercellular adhesion molecule-1 (ICAM-1) on the surface of cultured umbilical vein and saphenous vein endothelial cells was upregulated between 2.5- and 40-fold by rIL-1, rTNF, LPS and rIFN gamma corresponding to up to 5 X 10(6) sites/cell. Endothelial cell ICAM-1 was a single band of 90 kD in SDS-PAGE. Purified endothelial cell ICAM-1 reconstituted into liposomes and bound to plastic was an excellent substrate for both JY B lymphoblastoid cell and T lymphoblast adhesion. Adhesion to endothelial cell ICAM-1 in planar membranes was blocked completely by monoclonal antibodies to lymphocyte function associated antigen-1 (LFA-1) or ICAM-1. Adhesion to artificial membranes was most sensitive to ICAM-1 density within the physiological range found on resting and stimulated endothelial cells. Adhesion of JY B lymphoblastoid cells, normal and genetically LFA-1 deficient T lymphoblasts and resting peripheral blood lymphocytes to endothelial cell monolayers was also assayed. In summary, LFA-1 dependent (60-90% of total adhesion) and LFA-1-independent basal adhesion was observed and the use of both adhesion pathways by different interacting cell pairs was increased by monokine or lipopolysaccharide stimulation of endothelial cells. The LFA-1-dependent adhesion could be further subdivided into an LFA-1/ICAM-1-dependent component which was increased by cytokines and a basal LFA-1-dependent, ICAM-1-independent component which did not appear to be affected by cytokines. We conclude that ICAM-1 is a regulated ligand for lymphocyte-endothelial cell adhesion, but at least two other major adhesion pathways exist.

scholarly journals Binding of intercellular adhesion molecule 1 to β2-integrin regulates distinct cell adhesion processes on hepatic and cerebral endothelium

2018 ◽  
Vol 315 (3) ◽  
pp. C409-C421 ◽  
Author(s):  
Chun-Fang Tong ◽  
Yan Zhang ◽  
Shou-Qin Lü ◽  
Ning Li ◽  
Yi-Xin Gong ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Polymorphonuclear Neutrophils ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Intercellular Adhesion Molecule 1 ◽  
Cerebral Endothelium ◽  
Tissue Specific ◽  
Hepatic Sinusoid ◽  
Distinct Cell

Flowing polymorphonuclear neutrophils (PMNs) are forced to recruit toward inflamed tissue and adhere to vascular endothelial cells, which is primarily mediated by the binding of β2-integrins to ICAM-1. This process is distinct among different organs such as liver and brain; however, the underlying kinetic and mechanical mechanisms regulating tissue-specific recruitment of PMNs remain unclear. Here, binding kinetics measurement showed that ICAM-1 on murine hepatic sinusoidal endothelial cells (LSECs) bound to lymphocyte function-associated antigen-1 (LFA-1) with higher on- and off-rates but lower effective affinity compared with macrophage-1 antigen (Mac-1), whereas ICAM-1 on cerebral endothelial cells (BMECs or bEnd.3 cells) bound to LFA-1 with higher on-rates, similar off-rates, and higher effective affinity compared with Mac-1. Physiologically, free crawling tests of PMN onto LSEC, BMEC, or bEnd.3 monolayers were consistent with those kinetics differences between two β2-integrins interacting with hepatic sinusoid or cerebral endothelium. Numerical calculations and Monte Carlo simulations validated tissue-specific contributions of β2-integrin-ICAM-1 kinetics to PMN crawling on hepatic sinusoid or cerebral endothelium. Thus, this work first quantified the biophysical regulation of PMN adhesion in hepatic sinusoids compared with cerebral endothelium.

scholarly journals B7 but not intercellular adhesion molecule-1 costimulation prevents the induction of human alloantigen-specific tolerance.

1993 ◽  
Vol 178 (5) ◽  
pp. 1753-1763 ◽  
Author(s):  
V A Boussiotis ◽  
G J Freeman ◽  
G Gray ◽  
J Gribben ◽  
L M Nadler
Keyword(s):  
T Lymphocytes ◽  
Adhesion Molecule ◽  
Model System ◽  
Intercellular Adhesion ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Intercellular Adhesion Molecule 1 ◽  
Costimulatory Signals ◽  
Cell Commitment ◽  
Specific Tolerance

Presentation of antigen by the major histocompatibility complex to T lymphocytes without the requisite costimulatory signals does not induce an immune response but rather results in a state of antigen-specific unresponsiveness, termed anergy. To determine which costimulatory signals are critical for the T cell commitment to activation or anergy, we developed an in vitro model system that isolated the contributions of alloantigen and each candidate costimulatory molecule. Here, we show that transfectants expressing HLA-DR7 and either B7 or intercellular adhesion molecule 1 (ICAM-1) deliver independent costimulatory signals resulting in alloantigen-induced proliferation of CD4-positive T lymphocytes. Although equivalent in their ability to costimulate maximal proliferation of alloreactive T cells, B7 but not ICAM-1 induced detectable interleukin 2 secretion and prevented the induction of alloantigen-specific anergy. These results are consistent with the hypothesis that blockade of the ICAM-1:lymphocyte function-associated 1 pathway results in immunosuppression, whereas blockade of the B7:CD28/CTLA4 pathway results in alloantigen-specific anergy. This approach, using this model system, should facilitate the identification of critical costimulatory pathways which must be inhibited in order to induce alloantigen-specific tolerance before human organ transplantation.

scholarly journals Hyperketonemia increases monocyte adhesion to endothelial cells and is mediated by LFA-1 expression in monocytes and ICAM-1 expression in endothelial cells

2011 ◽  
Vol 301 (2) ◽  
pp. E298-E306 ◽  
Author(s):  
Justin L. Rains ◽  
Sushil K. Jain
Keyword(s):  
Endothelial Cells ◽  
Vascular Disease ◽  
Adhesion Molecule ◽  
Umbilical Vein ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Monocyte Adhesion ◽  
Intercellular Adhesion Molecule 1 ◽  
Monocyte Cell ◽  
Umbilical Vein Endothelial Cells

Frequent episodes of hyperketonemia are associated with a higher incidence of vascular disease. The objective of this study was to examine the hypothesis that hyperketonemia increases monocyte-endothelial cell (EC) adhesion and the development of vascular disease in diabetes. Human U937 and THP-1 monocyte cell lines and human umbilical vein endothelial cells (HUVECs) were cultured with acetoacetate (AA) (0–10 mM) or β-hydroxybutyrate (BHB) (0–10 mM) for 24 h prior to evaluating adhesion and adhesion molecule expression. The results demonstrate a significant ( P < 0.01) increase in both U937 and THP-1 adhesion to HUVEC monolayers treated with 4 mM AA compared with control. Equal concentrations of BHB resulted in similar increases in monocyte-EC adhesion. Similarly, treatments of AA or BHB to isolated monocytes from human blood also show increases in adhesion to endothelial cells. intercellular adhesion molecule-1 (ICAM-1) was significantly increased on the surface of HUVECs and an increase in total protein expression with AA treatment compared with control. The expression level of lymphocyte function-associated antigen-1 (LFA-1) was increased in monocytes treated with AA, and LFA-1 affinity was altered from low to high affinity following treatment with both AA and BHB. Monocyte adhesion could be blocked when cells were preincubated with an antibody to ICAM-1 or LFA-1. Results also show a significant increase in IL-8 and MCP-1 secretion in monocytes and HUVECs treated with 0–10 mM AA. These results suggest that hyperketonemia can induce monocyte adhesion to endothelial cells and that it is mediated via increased ICAM-1 expression in endothelial cells and increased expression and affinity of LFA-1 in monocytes.

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