(1) The phagocytosis of human IgG, IgM, and C3 by granulocytes from various rheumatoid and nonrheumatoid sera and synovial fluids (SF) was investigated by direct examination of the patient's leucocytes and indirect testing by incubation of normal donor leucocytes with various sera and SF. (2) In rheumatoid arthritis (RA) phagocytosis of IgM, IgG, and C3 was common from sera and SF. There was a ...

Legionella pneumophila, the causative agent of Legionnaires' disease, is able to survive and multiply efficiently in a variety of mammalian cells. By using in vitro assays, the uptake of L. pneumophila into monocytes has shown to be mediated, at least in part, through attachment of complement-coated bacteria to complement receptors, but complement-independent phagocytosis could also be demonstr...

BACKGROUND High glucose concentration, through the activation of calcium channels, augments in vitro calcium entry into cells and leads to elevation in the basal levels of [Ca2+]i, the latter causes cell dysfunction. DESIGN OF STUDY The present study examined whether streptozotocin-induced diabetes mellitus in rats causes a rise in [Ca2+]i of PMNL and impairs their phagocytosis and whether tr...

Receptor-mediated phagocytosis is a complex process that mediates the internalization, by a cell, of other cells and large particles; this is an important physiological event not only in mammals, but in a wide diversity of organisms. Of simple unicellular organisms that use phagocytosis to extract nutrients, to complex metazoans in which phagocytosis is essential for the innate defence system, ...

All clinical isolates of Streptococcus pyogenes (group A streptococcus) share the ability to resist phagocytosis and grow in human blood. In many strains, this property is due to the expression of a single antiphagocytic M protein, while other strains express more than one M-like molecule, of which the role in phagocytosis resistance is unclear. In particular, all S. pyogenes strains of the OF+...

Phagocytosis of microorganisms by macrophages is an important host defense mechanism. While studying the phagocytosis of the human pathogenic fungus Cryptococcus neoformans, we noted that macrophage-like J774 cells with ingested fungal cells had frequent mitotic figures. By analyzing the relative proportion of phagocytic cells as a function of cell cycle phase, we observed an increase in S phas...

Some apoptotic processes, such as phosphatidylserine exposure, are potentially reversible and do not necessarily lead to cell death. However, phosphatidylserine exposure can induce phagocytosis of a cell, resulting in cell death by phagocytosis: phagoptosis. Phagoptosis of neurons by microglia might contribute to neuropathology, whereas phagoptosis of tumour cells by macrophages might limit can...