We have previously shown that CD18 and alpha4 integrin were important in the adherence of emigrated neutrophils to cardiac myocytes. Whether either of these molecules is important in myocyte dysfunction is unclear. In this study, we measured contractility as an index of myocyte function. Control contractility was compared with shortening response in myocytes exposed to neutrophils in the presen...

PURPOSE A critical early event in the pathogenesis of diabetic retinopathy is leukocyte adhesion to the diabetic retinal vasculature. The process is mediated, in part, by intercellular adhesion molecule-1 (ICAM-1) and results in blood-retinal barrier breakdown and capillary nonperfusion. This study evaluated the expression and function of the corresponding ICAM-1-binding leukocyte beta2-integri...

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...

Natural polyamines, spermine, spermidine, and putrescine, play a pivotal role in the regulation of gene expression; therefore, the age-dependent decreases and the disease-dependent increases in polyamine synthesis suggest a possible contribution of polyamines to the age-related and disease-associated changes in cellular function. In this study, we examined the effects of polyamines on the cellu...

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...

Cryptococcus neoformans, a facultative intracellular pathogen of macrophages, is unique among medically important fungi in its possession of a polysaccharide capsule. Capsule represents the organism's major virulence factor. In the absence of opsonins, binding of encapsulated C. neoformans to macrophages is minimal. Following incubation in serum, C. neoformans potently activates complement, res...