The epoxygenase CYP2J2 has an emerging role in inflammation and vascular biology. The role of CYP2J2 in phagocytosis is not known and its regulation in human inflammatory diseases is poorly understood. Here we investigated the role of CYP2J2 in bacterial phagocytosis and its expression in monocytes from healthy controls and Crohns disease patients. CYP2J2 is anti-inflammatory in human periphera...

An arginine-glycine-aspartic acid sequence (RGD in the single letter code for amino acids) is present in the cell attachment site of both vitronectin and fibronectin. Inasmuch as fibronectin and synthetic peptides containing RGD enhance ingestion of opsonized particles by monocytes, we investigated the effects of vitronectin on phagocytosis by monocytes of sheep erythrocytes bearing IgG (EA) or...

Diverse receptors, including Fc receptors and 2 integrins (complement receptor-3 [CR3], CD11b/CD18), have been implicated in phagocytosis, but their distinct roles and interactions with other receptors in particle engulfment are not well defined. CD44, a transmembrane adhesion molecule involved in binding and metabolism of hyaluronan, may have additional functions in regulation of inflammation ...

Mono-Mac-6 (MM6) human monocytes ingest IgG-opsonized particles better than other human cell lines. We compared the phagocytic signaling pathway in MM6 with human monocytes. MM6 expressed FcgammaRI at levels similar to monocytes, whereas FcRgammaII expression was approximately double. MM6 ingested IgG-opsonized erythrocytes (EIgG) in a calcium-independent manner. Incubation of MM6 with bromoeno...

Thirteen chemotherapeutic agents were tested for modulatory activity on phagocytosis by human granulocytes and monocytes. Phagocytosis, phagocytic index, and intracellular bactericidal activity were assessed using Staphylococcus aureus, smooth strain of Escherichia coli, and latex particles. Modulation of phagocytic activity depended on the type of particle used and the presence of serum in the...

Mucoid Pseudomonas aeruginosa colonizes and infects the respiratory tract of most older patients with cystic fibrosis. These bacteria resist both opsonin-dependent and -independent phagocytosis by human polymorphonuclear leukocytes and monocyte-derived macrophages. Resistance to phagocytosis is thought to be mediated in part by the mucoid exopolysaccharide associated with the bacterial surface....

Under a variety of pathologic conditions, glial cells of the retina are capable of phagocytosis. Although phagocytosis may play a role in retinal pathobiology, the regulation of the phagocytic activity of retinal glial cells is poorly understood. We used a culture system to study phagocytosis by human retinal glial cells. The cultured cells were obtained from adult postmortem eyes and were immu...

Phagocytosis is a fundamental process of cells to capture and ingest foreign particles. Small unicellular organisms such as free-living amoeba use this process to acquire food. In pluricellular organisms, phagocytosis is a universal phenomenon that all cells are able to perform (including epithelial, endothelial, fibroblasts, etc.), but some specialized cells (such as neutrophils and macrophage...

Phagocytosis of Ab-coated pathogens is mediated through FcγRs, which activate intracellular signaling pathways to drive actin cytoskeletal rearrangements. Abl and Arg define a family of nonreceptor tyrosine kinases that regulate actin-dependent processes in a variety of cell types, including those important in the adaptive immune response. Using pharmacological inhibition as well as dominant ne...

Pseudomonas aeruginosa causes severe respiratory tract infections in patients with cystic fibrosis (CF). We have been examining nonopsonic phagocytosis of P. aeruginosa by macrophages. To study the P. aeruginosa-macrophage interaction at the molecular level, we have constructed a transposon Tn5G bank in a clinical isolate of P. aeruginosa (strain 4020) and identified mutants resistant to nonops...