A surface 75-kDa protein with acid phosphatase activity recognized by monoclonal antibodies that inhibit Paracoccidioides brasiliensis growth.
Paracoccidioides brasiliensis is a thermo-dimorphic fungus responsible for paracoccidioidomycosis (PCM), a systemic granulomatous mycosis prevalent in Latin America. The fungus releases many antigens which may be transiently bound to its cell surface. Some of them may show enzymatic functions essential for maintaining many cell processes and survival of the microorganism at different conditions. In this study, we report the characterization of a secreted 75kDa protein from P. brasiliensis with phosphatase activity. Biologic function of the molecule was demonstrated using two specific mAbs produced and characterized as IgM and IgG isotypes. Confocal microscopy and flow cytometry analysis demonstrated that both mAbs recognized the protein on the fungus surface, mainly in its budding sites. In vitro experiments showed that fungal growth was inhibited by blocking the protein with mAbs. In addition, opsonized yeast cells with both mAbs facilitated phagocytosis by murine peritoneal macrophages. Passive immunization using mAbs before P. brasiliensis mice infection reduced colony-forming units (CFU) in the lungs as compared with controls. Histopathology showed smaller inflammation, absence of yeast cells and no granuloma formation.
Xander
Patrícia
P
Disciplina de Imunologia, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, UNIFESP, Rua Botucatu 862, 04023-901 São Paulo, Brazil.
Vigna
Ana Flávia
AF
Feitosa
Luciano Dos Santos
Ldos S
Pugliese
Lívia
L
Bailão
Alexandre Melo
AM
Soares
Célia Maria de Almeida
CM
Mortara
Renato Arruda
RA
Mariano
Mario
M
Lopes
José Daniel
JD
D000135:Acid Phosphatase / Q000276:immunology* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000096:biosynthesis / Q000276:immunology*; D000946:Antigens, Fungal / Q000276:immunology / Q000378:metabolism; D005656:Fungal Proteins / Q000276:immunology* / Q000378:metabolism; D007116:Immunization, Passive; D017737:Macrophages, Peritoneal / Q000382:microbiology; D008297:Male; D008565:Membrane Proteins / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010228:Paracoccidioides / Q000254:growth & development* / Q000276:immunology; D010229:Paracoccidioidomycosis / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D010587:Phagocytosis
D000911:Antibodies, Monoclonal; D000946:Antigens, Fungal; D005656:Fungal Proteins; D008565:Membrane Proteins; D000135:Acid Phosphatase