Phagocyte-mediated killing of Candida tropicalis.
Human peripheral monocytes (MO), neutrophils (PMN), and lymphocytes (PBL) were tested for their ability to kill Candida tropicalis. With incubation times between 30 min and 2 h, unstimulated MO and PMN, but not PBL, were efficient killers of C. tropicalis. Both leukocyte subsets were able to kill at minimum 2.5:1 effector to target ratios. Pre-incubation of MO for 24 h with interferon-gamma or tumor necrosis factor (TNF) increased their ability to kill yeast targets. TNF alone had no effect on C. tropicalis targets at concentrations up to 1000 U/ml. PBL activated for 4 d with interleukin-2 did not kill yeast targets. PMN exhibited more cytocidal efficiency per cell than MO in these assays. Direct contact of effectors and targets was required; no significant killing by PMN or MO supernatants was measured. PMN-mediated killing, but not MO killing, was inhibited by a mixture of catalase and superoxide dismutase suggesting that oxygen-dependent killing mechanisms were partially responsible for candidacidal activity.
Lindemann
R A
RA
UCLA School of Dentistry.
Franker
C K
CK
D002175:Candida / Q000276:immunology*; D002374:Catalase / Q000494:pharmacology; D002478:Cells, Cultured; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007700:Kinetics; D008214:Lymphocytes / Q000276:immunology*; D009000:Monocytes / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology*; D010587:Phagocytosis; D013482:Superoxide Dismutase / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D007376:Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D002374:Catalase; D013482:Superoxide Dismutase