title: Quantifying phagocytosis of Mycobacterium avium complex by human monocytes in whole blood.
abstract: Studies of phagocytic efficiency in cells of the macrophage lineage have assumed additional importance since the discovery that HIV infection of these cells impairs their immune function. A rapid method has been developed for measuring phagocytosis of the opportunistic pathogen Mycobacterium avium complex by human monocytes. Fluoresceinated M. avium complex (F-MAC) was incubated with whole blood at 37 degrees C and the fluorescence of extracellular F-MAC was quenched using a vital blue stain. Monocytes were then stained with a monoclonal antibody (mAb) to human CD14 conjugated to phycoerythrin (PE) red cells were lysed, and the percentage of monocytes which had phagocytosed F-MAC was measured by flow cytometry. The results were reproducible in samples of blood taken from individual donors over a period of 1 or 2 weeks, and optimum F-MAC concentrations and an optimum incubation time were determined by experiment. This method has the advantages of requiring only a small volume of blood, not necessitating manipulation of cells before testing, and using a phagocytic target relevant to the pathogenesis of HIV infection.
authors.affiliation: AIDS Pathogenesis Research Unit, Macfarlane Burnet Centre for Medical Research, Fairfield, Victoria, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Hewish
authors.forename: A M
authors.initials: AM
authors.lastname: Meikle
authors.forename: S D
authors.initials: SD
authors.lastname: Hunter
authors.forename: S M
authors.initials: SM
authors.lastname: Crowe
mesh_terms: D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D006801:Humans; D009000:Monocytes / Q000276:immunology*; D015269:Mycobacterium avium Complex / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology*; D015203:Reproducibility of Results
chemical_list: D016650:Fluorescein-5-isothiocyanate