Macrophage expression of class II major histocompatibility complex gene products in Paracoccidioides brasiliensis-infected mice.
C57B1/6 isogenic mice infected with Paracoccidioides brasiliensis strains showed a disruption in the expression of Ia antigen. Expression slowly decreased during the course of the infection with a slight variation dependent on the route of inoculation and the fungal strain used, but production of interferon-gamma and tumor necrosis factor-alpha were observed. Suppression of Ia antigen expression and depression of the immunoproliferative responses of spleen cells were strongly correlated with nitric oxide levels. These parameters were inhibited when the animals were treated with nitro-L-arginine, which resulted in inhibition the activation of nitric oxide (NO) production. Analysis of the data showed that changes in the expression of the Ia antigen occur in P. brasiliensis infection and are strongly correlated with NO levels. These phenomena may be interrelated and reflect macrophage activation that contributes to the control of the disease and to the immunosuppression observed during the course of the infection.
Bocca
A L
AL
Department of Cell Biology, Biology Institute, Faculty of Health Sciences, University of Brasília, Brasília DF, Brazil.
Silva
M F
MF
Silva
C L
CL
Cunha
F Q
FQ
Figueiredo
F
F
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation; D005802:Genes, MHC Class II / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis* / Q000235:genetics; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000096:biosynthesis*; D019335:Nitroarginine / Q000494:pharmacology*; D010229:Paracoccidioidomycosis / Q000188:drug therapy / Q000276:immunology* / Q000378:metabolism; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000949:Histocompatibility Antigens Class II; D014409:Tumor Necrosis Factor-alpha; D019335:Nitroarginine; D009569:Nitric Oxide