Treatment of serum with supernatants from cultures of Candida albicans reduces its serum-dependent phagocytosis
Braz. j. microbiol
;
33(1): 79-83, jan.-mar. 2002. ilus, graf
Article
in English
| LILACS
| ID: lil-325374
ABSTRACT
Candida albicans is a potent activator of the complement system, and heat labile opsonins produced by activation of C3 (C3b and iC3b) enhance phagocytosis of C. albicans mediated by complement receptors. In this study we treated mouse serum with supernatants from cultures of a protease producer strain of C. albicans and evaluated the ability of this serum to enhance phagocytosis of C. albicans. Cell-free supernatants from cultures of C. albicans were concentrated 5 fold and added to mouse serum for 30 min at 37§C, before using this serum for opsonization of glutaraldehyde-fixed yeast cells. We observed that normal mouse serum increased about 3 fold the phagocytosis of C. albicans by mice peritoneal macrophages, whereas supernatant-treated serum did not increase phagocytosis. This effect of supernatants on serum was prevented by addition of pepstatin (5 µg/ ml; an inhibitor of C. albicans acid proteases) to the medium. Serum treated with supernatants from cultures of a protease-deficient mutant of C. albicans also increased about 3 fold phagocytosis of the yeast. These results suggest that a protease produced by C. albicans causes proteolysis of serum opsonins, thereby reducing the phagocytosis of the yeast.
Full text:
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Index:
LILACS (Americas)
Main subject:
Phagocytosis
/
Yeasts
/
In Vitro Techniques
/
Candida albicans
/
Proteins
/
Mice
Type of study:
Diagnostic study
Language:
English
Journal:
Braz. j. microbiol
Journal subject:
Microbiology
Year:
2002
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Univerdade Estadual de Londrina/BR
/
Universidade Estadual de Londrina/BR
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