Early membrane exposure of phosphatidylserine followed by late necrosis in murine macrophages induced by Candida albicans from an HIV-infected individual.
The hypothesis that Candida albicans isolate (CR1) from an HIV-infected individual induced apoptosis of macrophages was examined by optical microscopy, binding of annexin V-FITC and analyses of DNA degradation (TUNEL tests and agarose gel electrophoresis). Resident murine peritoneal macrophages co-incubated for 5-15 min with C. albicans CR1 bound annexin V, whereas macrophages incubated with either heat-inactivated strain CR1, C. albicans 577 (isolated from a patient with mucocutaneous candidiasis) or C. albicans FCF14 (a mutant that did not produce proteases and phospholipases) did not bind annexin for up to 2 h of observation. However, macrophages exposed to C. albicans CR1 did not present the pattern of DNA degradation typical of apoptosis. Macrophages became increasingly permeable to propidium iodide from 30 min to 2 h after their exposure to C. albicans CR1. Most of the phagocytosed C. albicans CR1 yeast cells switched to germ-tubes inside the macrophages after incubation for 1-2 h. These results show that macrophages exposed to C. albicans CR1 presented early signs of apoptosis but progressed to necrosis, and suggest that Candida strains that readily switch to germ-tubes inside those apoptotic cells might have a competitive advantage in vivo because released germ-tubes resist further attack by macrophages.
Panagio
L A
LA
Felipe
I
I
Departments of Microbiology, *General Pathology and †Physiological Sciences, Universidade Estadual de Londrina, 86051-990 Londrina, Brazil.
Vidotto
M C
MC
Gaziri
L C J
LCJ
Departments of Microbiology, *General Pathology and †Physiological Sciences, Universidade Estadual de Londrina, 86051-990 Londrina, Brazil.
D017088:AIDS-Related Opportunistic Infections / Q000150:complications*; D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis; D002176:Candida albicans / Q000472:pathogenicity*; D002178:Candidiasis, Chronic Mucocutaneous / Q000150:complications*; D002478:Cells, Cultured; D015658:HIV Infections / Q000150:complications* / Q000382:microbiology; D006801:Humans; D017737:Macrophages, Peritoneal / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D008297:Male; D051379:Mice; D010436:Pepstatins; D010587:Phagocytosis; D010718:Phosphatidylserines / Q000032:analysis / Q000378:metabolism*; D011419:Propidium; D011480:Protease Inhibitors; D013045:Species Specificity; D013997:Time Factors
D017304:Annexin A5; D010436:Pepstatins; D010718:Phosphatidylserines; D011480:Protease Inhibitors; D011419:Propidium; C031375:pepstatin