TY - JOUR
T1 - Resistance of melanized yeast cells of Paracoccidioides brasiliensis to antimicrobial oxidants and inhibition of phagocytosis using carbohydrates and monoclonal antibody to CD18
AU - da Silva, Marcelo Barbosa
AU - Thomaz, Luciana
AU - Marques, Alexandre Ferreira
AU - Svidzinski, Artur E.
AU - Nosanchuk, Josh D.
AU - Casadevall, Arturo
AU - Travassos, Luiz R.
AU - Taborda, Carlos P.
PY - 2009/7
Y1 - 2009/7
N2 - 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.
AB - 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.
KW - Anti-CD18 antibody
KW - Antimicrobial oxidants
KW - Melanin
KW - P. brasiliensis
UR - http://www.scopus.com/inward/record.url?scp=70149110410&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70149110410&partnerID=8YFLogxK
U2 - 10.1590/s0074-02762009000400019
DO - 10.1590/s0074-02762009000400019
M3 - Article
C2 - 19722091
AN - SCOPUS:70149110410
SN - 0074-0276
VL - 104
SP - 644
EP - 648
JO - Memorias do Instituto Oswaldo Cruz
JF - Memorias do Instituto Oswaldo Cruz
IS - 4
ER -