title: Granulomatous reaction in the hamster cheek pouch induced by killed Paracoccidioides brasiliensis.
abstract: We have studied the role of Paracoccidioides brasiliensis viability in the morphology of paracoccidioidomycotic granulomas in the hamster cheek pouch, an immunologically privileged site. Naive (N = 75) and previously sensitized (N = 50) two-month old male hamsters (Mesocricetus auratus) were inoculated into the pouch with 5 x 10(5) live or heat- or formalin-killed fungi. Previously sensitized animals presented a positive footpad test and immunodiffusion demonstrable antibodies (titer 1/32), at the time of sacrifice; naive animals were always negative for those immunological tests. The histological results showed that, like viable P. brasiliensis, killed fungi evoke typical epithelioid granulomas in 100% of animals, even in the absence of immunodiffusion or footpad test detectable immune response. The granulomas elicited by killed fungi were devoid of giant cells or a mononuclear cell halo, suggesting that live proliferating fungi or their products may be involved in these events.
authors.affiliation: Departamento de Ciências Biológicas, Faculdade de Ciências, Universidade Estadual Paulista, Brasil.
authors.forename: M S
authors.initials: MS
authors.lastname: Arruda
authors.forename: M R
authors.initials: MR
authors.lastname: Montenegro
mesh_terms: D000818:Animals; D000908:Antibodies, Fungal / Q000032:analysis; D006224:Cricetinae; D006099:Granuloma / Q000276:immunology* / Q000473:pathology; D008297:Male; D008647:Mesocricetus / Q000276:immunology*; D010228:Paracoccidioides / Q000276:immunology / Q000472:pathogenicity*
chemical_list: D000908:Antibodies, Fungal