Immunosuppressive effect of paracoccidioidomycosis sera on the proliferative response of normal mononuclear cells. Identification of a Paracoccidioides brasiliensis 34-kDa polypeptide in circulating immune complexes.
In this paper we relate that sera from paracoccidioidomycosis patients inhibited the mitogen-induced proliferative responses of normal mononuclear cells. Treatment of these sera with 2.5% polyethyleneglycol (PEG), a method classically used to precipitate immune complexes, significantly reduced their inhibitory activity. Immunoblot analysis of the PEG precipitates identified a 34-kDa polypeptide, recognized by rabbit anti-P. brasiliensis IgG. Patient mononuclear cells showed partial restoration of their proliferative capacity after 24 h culture in medium alone, which suggests release of membrane-bound molecules in the culture medium. These findings indicate that circulating P. brasiliensis antigens, complexed or not with antibodies, may play a negative immunoregulatory effect in the mitogen-induced proliferative responses of paracoccidioidomycosis patients.
Chequer-Bou-Habib
D
D
Department of Immunology (WHO Collaborating Center for Research in the Immunology of Parasitic Diseases), Fundaçao Oswaldo Cruz, Rio de Janeiro, Brazil.
Ferreira-da-Cruz
M de F
Mde F
Galvão-Castro
B
B
D000818:Animals; D000908:Antibodies, Fungal / Q000097:blood* / Q000502:physiology*; D000936:Antigen-Antibody Complex / Q000097:blood / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D007106:Immune Sera / Q000502:physiology*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008970:Molecular Weight; D010229:Paracoccidioidomycosis / Q000097:blood* / Q000276:immunology*; D011092:Polyethylene Glycols / Q000494:pharmacology; D011817:Rabbits
D000908:Antibodies, Fungal; D000936:Antigen-Antibody Complex; D007106:Immune Sera; D007166:Immunosuppressive Agents; D011092:Polyethylene Glycols