Regulation of leukocyte integrins

1992 ◽  
pp. 183-187
Author(s):  
S. D. Wright ◽  
A. Hermanowski-Vosatka ◽  
J. A. G. Van Strijp ◽  
P. A. Detmers
Keyword(s):  
2009 ◽  
Vol 9 (4) ◽  
pp. 118-121 ◽  
Author(s):  
Annamaria Vezzani ◽  
Damir Janigro

A Role for Leukocyte-Endothelial Adhesion Mechanisms in Epilepsy. Fabene PF, Navarro MG, Martinello M, Rossi B, Merigo F, Ottoboni L, Bach S, Angiari S, Benati D, Chakir A, Zanetti L, Schio F, Osculati A, Marzola P, Nicolato E, Homeister JW, Xia L, Lowe JB, McEver RP, Osculati F, Sbarbati A, Butcher EC, Constantin G. Nat Med 2008;14(12):1377–1383. The mechanisms involved in the pathogenesis of epilepsy, a chronic neurological disorder that affects approximately one percent of the world population, are not well understood1,2,3. Using a mouse model of epilepsy, we show that seizures induce elevated expression of vascular cell adhesion molecules and enhanced leukocyte rolling and arrest in brain vessels mediated by the leukocyte mucin P-selectin glycoprotein ligand-1 (PSGL-1, encoded by Selplg) and leukocyte integrins41 and L2. Inhibition of leukocyte-vascular interactions, either with blocking antibodies or by genetically interfering with PSGL-1 function in mice, markedly reduced seizures. Treatment with blocking antibodies after acute seizures prevented the development of epilepsy. Neutrophil depletion also inhibited acute seizure induction and chronic spontaneous recurrent seizures. Blood-brain barrier (BBB) leakage, which is known to enhance neuronal excitability, was induced by acute seizure activity but was prevented by blockade of leukocyte-vascular adhesion, suggesting a pathogenetic link between leukocyte-vascular interactions, BBB damage and seizure generation. Consistent with the potential leukocyte involvement in epilepsy in humans, leukocytes were more abundant in brains of individuals with epilepsy than in controls. Our results suggest leukocyte-endothelial interaction as a potential target for the prevention and treatment of epilepsy.


1992 ◽  
Vol 4 (9) ◽  
pp. 1031-1040 ◽  
Author(s):  
Wei-Meng Jiang ◽  
David Jenkins ◽  
Qian Yuan ◽  
Euphemia Leung ◽  
K. H. Andy Choo ◽  
...  

Integrins ◽  
1994 ◽  
pp. 163-194 ◽  
Author(s):  
Mariano J. Elices
Keyword(s):  

1993 ◽  
Vol 5 (5) ◽  
pp. 551-558 ◽  
Author(s):  
Euphemia Leung ◽  
Paul E. Mead ◽  
Qian Yuan ◽  
Wei-Meng Jiang ◽  
James D. Watson ◽  
...  

2009 ◽  
pp. 115-132
Author(s):  
Eun Jeong Park ◽  
Motomu Shimaoka
Keyword(s):  

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2433 ◽  
Author(s):  
M. Amin Arnaout

Integrins comprise a large family of αβ heterodimeric cell adhesion receptors that are expressed on all cells except red blood cells and that play essential roles in the regulation of cell growth and function. The leukocyte integrins, which include members of the β1, β2, β3, and β7integrin family, are critical for innate and adaptive immune responses but also can contribute to many inflammatory and autoimmune diseases when dysregulated. This review focuses on the β2integrins, the principal integrins expressed on leukocytes. We review their discovery and role in host defense, the structural basis for their ligand recognition and activation, and their potential as therapeutic targets.


1990 ◽  
Vol 171 (5) ◽  
pp. 1753-1771 ◽  
Author(s):  
J P Metlay ◽  
M D Witmer-Pack ◽  
R Agger ◽  
M T Crowley ◽  
D Lawless ◽  
...  

Hybridoma fusions with hamster hosts were undertaken to generate mAbs to mouse spleen dendritic cells. Two mAb were obtained and used to uncover the distinct integrins of these APC. One, 2E6, bound a determinant common to all members of the CD11/CD18 family, most likely the shared 90 kD CD18 beta chain. 2E6 immunoprecipitated the characteristic beta 2 integrin heterodimers from lymphocytes (p180, 90; CD11a) and macrophages (p170,90; CD11b), but from dendritic cells, a p150,90 (presumably CD11c) integrin was the predominant species. 2E6 inhibited the binding function of the CD11a and CD11b integrins on B cells and macrophages in appropriate assays, but 2E6 exerted little or no inhibition on the clustering of dendritic cells to T cells early in primary MLR, suggesting a CD11/CD18-independent mechanism for this binding. The second mAb, N418, precipitated a 150, 90 kD heterodimer that shared the 2E6 CD18 epitope. This N418 epitope may be the murine homologue of the previously characterized human CD11c molecule, but the epitope was only detected on dendritic cells. N418 did not react with peritoneal macrophages, anti-Ig-induced spleen B blasts, or bulk lymph node cells. When used to stain sections of spleen, N418 stained dendritic cells in the T-dependent areas, much like anti-class II mAbs that were also generated in these fusions. In addition, N418 revealed nests of dendritic cells that punctuated the rim of marginal zone macrophages between red and white pulp. This localization positioned most dendritic cells at regions where arterial vessels and T cells enter the white pulp. We conclude that the p150, 90 heterodimer is the major beta 2 integrin of spleen dendritic cells, and we speculate that it may function to localize these APC at sites that permit access to the recirculating pool of resting T cells.


2007 ◽  
Vol 218 (1) ◽  
pp. 147-164 ◽  
Author(s):  
Olga Barreiro ◽  
Hortensia de la Fuente ◽  
María Mittelbrunn ◽  
Francisco Sánchez-Madrid

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3906-3906
Author(s):  
Nataly P. Podolnikova ◽  
Benjamin Bowen ◽  
Valeryi K. Lishko ◽  
Andriy V. Podolnikov ◽  
Tatiana Ugarova

Abstract Thrombus formation at sites of vascular injury must occur quickly to reduce blood loss, but is carefully controlled to limit vessel occlusion. Arrest of bleeding is mediated by adhesion and aggregation of platelets and the formation of the fibrin clot. While the interactions responsible for platelet adhesion and thrombus growth have been extensively researched, the mechanisms that limit platelet adhesion are not clear. We have previously demonstrated that plasma fibrinogen is a potent inhibitor of integrin-mediated leukocyte adhesion to fibrin clots and surface-bound fibrinogen, and have provided evidence that fibrinogen reduces cell adhesion by binding to the surface of fibrin rather than blocking leukocyte integrins. Accordingly, cells that engage fibrinogen molecules loosely bound to fibrin (soft substrate) are not able to consolidate their grip on the surface; subsequently, cells detach. Conversely, cells that adhere to the naked fibrin clot (rigid substrate) adhere firmly. Since fibrin and immobilized fibrinogen support platelet adhesion, we examined the effect of soluble fibrinogen on integrin αIIbβ3-mediated adhesion. We show that the anti-adhesive fibrinogen layer formed on the surface of fibrin inhibits platelet adhesion. We also demonstrate that fibrinogen immobilized on plastic at high densities (>20 μg/ml) supports weak platelet adhesion whereas at low concentrations (∼2 μg/ml) it is highly adhesive. An investigation of the mechanism underlying differential platelet adhesion indicates that platelet adhesion to rigid substrates (low-density fibrinogen and naked fibrin gel) induces much stronger phosphorylation of FAK and Syk kinases than that to soft substrates (high-density fibrinogen and fibrin exposed to soluble fibrinogen). Furthermore, the rigid, but not the soft substrates induce recruitment of signaling molecules talin and skelemin to αIIbβ3-containing focal adhesions. Consistent with their limited ability to induce sufficient signaling, soft substrates do not support platelet spreading. These data suggest that circulating fibrinogen prevents stable platelet adhesion by modifying the mechanical properties of the fibrin clot’s surface which results in reduced force generation and insufficient signaling.


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