Resistance of melanized yeast cells of Paracoccidioides brasiliensis to antimicrobial oxidants and inhibition of phagocytosis using carbohydrates and monoclonal antibody to CD18
Mem. Inst. Oswaldo Cruz
;
104(4): 644-648, July 2009. graf
Article
in English
| LILACS
| ID: lil-523734
ABSTRACT
Paracoccidioides brasiliensis, a thermal dimorphic fungal pathogen, produces a melanin-like pigment in vitro and in vivo. We investigated the involvement of carbohydrates and monoclonal antibody to CD18, on phagocytosis inhibition, involving macrophage receptors and the resistance of melanized fungal cells to chemically generated nitric oxide (NO), reactive oxygen species (ROS), hypochlorite and H2O2. Our results demonstrate that melanized yeast cells were more resistant than nonmelanized yeast cells to chemically generated NO, ROS, hypochlorite and H2O2, in vitro. Phagocytosis of melanized yeast cells was virtually abolished when mannan, N-acetyl glucosamine and anti-CD18 antibody were added together in this system. Intratracheal infection of BALB/c mice, with melanized yeast cells, resulted in higher lung colony forming units, when compared to nonmelanized yeast cells. Therefore, melanin is a virulence factor of P. brasiliensis.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Paracoccidioides
/
Phagocytosis
/
Oxidants
/
Macrophages
/
Melanins
/
Antifungal Agents
Limits:
Animals
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Mem. Inst. Oswaldo Cruz
Journal subject:
Tropical Medicine
/
Parasitology
Year:
2009
Type:
Article
/
Project document
Affiliation country:
Brazil
/
United States
Institution/Affiliation country:
Albert Einstein College of Medicine/US
/
Universidade Federal de São Paulo/BR
/
Universidade de São Paulo/BR
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