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Integrin-Dependent Responses in Human Basophils
Published in Bruce S. Bochner, Adhesion Molecules in Allergic Disease, 2020
Jane A. Warner, Kirsty Rich, Kirstin Goldring
As mentioned above, in addition to the β1 and β2 integrins, basophils also possess ICAM-1, 2, and 3, members of the immunoglobulin superfamily and ligands for the β2 integrins. Sianni et al. (64) have shown that though ligation of ICAM-3 does not initiate basophil degranulation directly, it increased a subsequent response to anti-IgE. The effects of cross-linking of ICAM-3 were detectable within 1 min and gradually declined over the next 30 min. This contrasts with the studies on cross-linking of VLA-4, where the effects on anti-IgE induced release were maximal at 60 min and could not be detected at all at 5 min (59). It is tempting to speculate that the differences in the kinetics reflect the very distinct roles that ICAM-3 and VLA-4 play on the cell surface and in particular the length of time that they are likely to be engaged during the normal process of adhesion and recruitment. Finally, cross-linking of ICAM-3 also increases the binding of basophils to activated and unstimulated endothelial cells (64), supporting the hypothesis that engagement of one adhesion protein may increase the activity of other molecules in the adhesion cascade.
Role of dendritic cells in integrating immune responses to luminal antigens
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
Brian L. Kelsall, Maria Rescigno
DCs that have captured antigens undergo a process of maturation, either constitutively through unclear mechanisms that may involve changes in homeotypic adhesion or through activation by pattern-recognition receptors (PRRs) or inflammatory cytokines (interleukin [IL]-1α/β, tumor necrosis factor [TNF]-α), resulting in increased maturation and migration. DC maturation is characterized by a decreased capacity to take up antigen (to prevent processing of additional self-antigens), increased processing of antigen into MHC I and II and peptide complexes, and expression of costimulatory molecules. Expression of MHC peptide complexes and costimulatory molecules is markedly increased on the expanded cell surface that results from formation of extended dendritic processes. This maturation process coincides with DC migration from nonlymphoid tissues or from the marginal zones to T-cell zones of draining lymph nodes due to expression of CCR7, which allows DCs to enter lymphatics. cDCs localize along connective tissue fibers and present the antigen to circulating naïve T cells attracted by chemokines such as DC-derived CCL18. In addition, mature DCs express adhesion molecules, including LFA-1 (CD11a/CD18), LFA-3 (CD58), and DC-SIGN (CD209). DC-SIGN binds transiently and with high avidity to ligands expressed by naïve T cells, thereby enhancing T-cell sampling of DC-expressed MHC–peptide complexes. LFA-1 and LFA-3 expressed on mature DCs bind naïve T-cell ICAM-3 and CD2, respectively, promoting T-cell activation.
The Role of β2 Integrins in Leukocyte Adhesion
Published in Yoshikazu Takada, Integrins: The Biological Problems, 2017
ICAM-3 was originally found by adhesion studies of the SKW3 T cell lymphoma line to αLβ2.80 It has a strong presence on all resting, nonactivated monocytic cells, much more than either CD54 or ICAM-2 and is not found on either resting or activated endothelial cells. Anti-ICAM-3 MAb strongly inhibit unactivated T cells from binding to αLβ2, suggesting a major role for ICAM-3 in αLβ2-mediated leukocyte binding to lymphocytes. The specific roles of ICAM-1, -2, and -3 in cell adhesion are further evidence of ligand-specific integrin-mediated binding to specific cell targets.
Increased Expressions of ICAM-2 and ICAM-3 in Pterygium
Published in Current Eye Research, 2019
Seniz Demiryürek, Ahmet Saracaloglu, Sabit Kimyon, Alper Mete, Omer Eronat, Ebru Temiz, Gülper Nacarkahya, Zeynep Sav Tunca, Betül Düzen, Oguzhan Saygili, Kıvanc Güngör, Metin Karakök, Abdullah T. Demiryürek
The functional roles of increased ICAM-3 expression in pterygium are unknown. ICAM-3 is expressed by some diseased leukocytes, macrophages, and endothelial cells.18 ICAM-3 stimulates adhesion of apoptotic leukocytes to phagocytic macrophages and suppresses lymphocyte survival through induction of apoptosis.19,20 ICAM-3 can also modulate leukocyte apoptosis.21 ICAM-3 on eosinophils and neutrophils contribute to adhesion and intracellular signaling. Taken together, these studies suggest that ICAM-3-induced apoptosis and adhesion may have pronounced implications in inflammation and pterygium development.