The beta 2 integrin receptor CD11b/CD18 mediates adhesion to the endothelial lining as well as to extracellular matrix components. The present study was undertaken to investigate peripheral human blood monocytes (BMs) and alveolar macrophages (AMs) with respect to quantitative levels of CD11b/CD18 and adhesion properties in relation to the state of activation. BMs and AMs were recruited from he...

The CD11b (or macrophage-1 antigen; MAC-1) subunit of the leukocyte integrin family forms a noncovalently associated heterodimeric structure with the CD18 (beta) subunit on the surface of human granulocytes and monocyte/macrophages, where it enables these myeloid cells to participate in a variety of adherence-related activities. Expression of the CD11b subunit is restricted to cells of the myel...

It was hypothesized that there would be an upregulation of systemic neutrophil CD11b expression in pneumonia. Expression of CD11b and concentrations of soluble intercellular adhesion molecule (ICAM)-1 and E-selectin were evaluated as potential surrogate markers of the severity of pneumonia. Possible age-related immunosenescence in relation to neutrophil CD11b expression in elderly patients with...

In the present study, we investigated the mechanisms by which plasma lipoproteins modulate the integrin-dependent adhesion properties of monocytes. LDL induced the expression of the monocyte CD11b in vitro as well as in vivo via intracellular signaling mechanisms involving calcium transients. The effect on CD11b transcription was specific for native LDL and was blocked by a neutralizing anti-LD...

Tuned and distinct responses of macrophages and dendritic cells to Toll-like receptor 4 (TLR4) activation induced by lipopolysaccharide (LPS) underpin the balance between innate and adaptive immunity. However, the molecule(s) that confer these cell-type-specific LPS-induced effects remain poorly understood. Here we report that the integrin α(M) (CD11b) positively regulates LPS-induced signallin...

Interleukin-10 (IL-10) plays a central role in regulation of intestinal mucosal homeostasis and prevention of inflammatory bowel disease (IBD). We previously reported that CD11b(hi) regulatory dendritic cells (DCs) can produce more IL-10, and CD11b can negatively regulate Toll-like receptors (TLRs)-induced inflammatory responses in macrophages. However whether CD11b and its signaling can contro...

Foxp3 Tregs are essential for maintaining immune tolerance in mice and men. Except for expression in a minor population of CD8 T cells,1 Foxp3 is currently believed to be restricted to CD4 Tregs in mice, because widespread nonhematopoietic Foxp3 expression and its putative implication in tolerance have been refuted.2,3 Thus, the employment of Foxp3 reporter mice, including Foxp3DTR-eGFP (DEREG)...

PURPOSE To explore modifications in signal mechanisms involving CD11b and leukocyte adhesion in patients under haemodialysis (HD). METHODS Samples were obtained from uremic patients at baseline, 15 and 120 min of HD from both arterial and venous lines. CD11b expression was studied by flow cytometry. To study signalling mechanisms, CD11b was immunoprecipitated using a specific antibody. Immuno...

IL-17 is a proinflammatory cytokine produced by various immune cells. Polymorphonuclear neutrophils (PMNs) are the first line of defense in bacterial infection and express surface Toll-like receptor 9 (sTLR9). To study the relationship of sTLR9 and IL-17 in PMNs during bacterial infection, we infected mice with E. coli intraperitoneally to establish a septic peritonitis model for studying the P...