Human polymorphonuclear leukocytes (PMN) released large quantities of hydrogen peroxide in response to tumor necrosis factor, but only when the cells were adherent to surfaces coated with extracellular matrix proteins. The PMN did not respond when exposed to cytokines and matrix proteins in suspension, or when exposed to cytokines while adherent to surfaces coated with stearic acid. PMN from ch...

Neutrophil emigration in response to acid aspiration does not require the adhesion complex, CD11/ CD18. This study examined the role of CD11b/CD18 using the anti-CD11b F(ab')2, 1B6, in focal HCI-induced intracapillary neutrophil sequestration and edema formation within rat lungs, as well as the effect of pretreatment with endotoxin on this injury. The results show that at the site of aspiration...

The β2 integrins are expressed exclusively on leukocytes and participate in many immune and inflammatory processes. This subfamily comprises four heterodimeric glycoproteins with a common β-subunit, designated β2 (CD18). Spontaneous mutations of the CD18 gene result in leukocyte adhesion deficiency type I (LAD-I). Low level of CD18 expression has also been implicated in the pathogenesis of psor...

The activation of phagocytes by the lipid A moiety of LPS has been implicated in the pathogenesis of Gram-negative sepsis. While two LPS receptors, CD14 and CD11/CD18, have been associated with cell signaling, details of the LPS signal transduction cascade remain obscure. CD14, which exists as a GPI-anchored and a soluble protein, lacks cytoplasmic-signaling domains, suggesting that an ancillar...

Mo1, LFA-1, and p150,95 are structurally related glycoproteins of the CD11/CD18 complex that are expressed on the membrane of human leukocytes. In the neutrophil, the surface expression of the CD11/CD18 complex is up-modulated (Mo1 greater than p150,95 much greater than LFA-1) by stimulatory factors that include calcium ionophore A23187, phorbol myristate acetate (PMA), and N-L-formyl-L-leucyl-...

Adherence of lymphocytes to the fungus is the first step in the direct lymphocyte-mediated antifungal effect against Candida albicans. In this study we identified macrophage-1 antigen (Mac-1) (CD11b/CD18, alpha(M)/beta(2)) as the lymphocyte surface structure responsible for the adhesion of activated lymphocytes to the hyphal form of the fungus. Antibodies specific for epitopes of the alpha-subu...

Tick saliva contains anti-inflammatory and immunosuppressive substances that facilitate blood feeding and enhance tick-vectored pathogen transmission, including Anaplasma phagocytophila an etiologic agent of granulocytic ehrlichiosis. As such, inflammation at a tick-feeding site is strikingly different than that typically observed at other sites of inflammation. Up-regulation of CD11b/CD18 occu...

We evaluated the effects of alpha-Toc on surface expression of CD11b/CD18 on polymorphonuclear leukocytes (PMN) stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and oxidized low-density lipoprotein (oxLDL). Incubation of PMN with fMLP (1 microM) or oxLDL (100 microg/mL) increased CD11b/CD18 expression; pretreatment with alpha-Toc reduced in a dose-dependent manner. PMN obtained fr...

Neutrophils and macrophages are important constituents of the hepatic inflammatory infiltrate in non-alcoholic steatohepatitis. These innate immune cells express CD18, an adhesion molecule that facilitates leukocyte activation. In the context of fatty liver, activation of infiltrated leukocytes is believed to enhance hepatocellular injury. The objective of this study was to determine the degree...

We used mAbs against polymorphonuclear leukocyte (PMN) surface proteins to investigate the mechanisms by which stimulated human neutrophils (PMNs) adhere in vitro to laminin, the major glycoprotein of mammalian basement membrane. mAb IB4, which is directed against the common beta 2 chain of the CD11/CD18, only partially inhibited the adherence of PMA-stimulated PMNs to both laminin and to suben...