title: Programmed cell death in thymus during experimental paracoccidioidomycosis.
abstract: Many works have shown that immunosuppressive effects induced by systemic mycosis can be related to primary lymphoid organ damage. Previous studies in our laboratory showed that Paracoccidioides brasiliensis was able to invade the thymus, inducing a severe atrophy with significant reduction of cortical area along with a loss of cortico-medullary boundary. The objective of the present study was to investigate whether thymic atrophy is caused by programmed cell death (PCD) and to examine the ultrastructural characteristics of the thymus in experimentally infected BALB/c mice. The results revealed an eightfold increase in the apoptotic index occurring by day 5 post infection, i.e., during early stages of the infection, shown by immunohistochemistry. In addition, typical cell alterations of autophagic PCD were observed by transmission electron microscopy. Taken together, these results reinforce the idea that thymic alterations may be involved in the immunosuppressive phenomenon frequently associated with paracoccidioidomycotic infection.
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz s/n, Caixa Postal 6109, 13083-970 Campinas-SP, Brazil. souto@unicamp.br
authors.forename: Paula C S
authors.initials: PC
authors.lastname: Souto
authors.forename: Vânia N
authors.initials: VN
authors.lastname: Brito
authors.forename: Jacy
authors.initials: J
authors.lastname: Gameiro
authors.forename: Maria Alice
authors.initials: MA
authors.lastname: da Cruz-Höfling
authors.forename: Liana
authors.initials: L
authors.lastname: Verinaud
mesh_terms: D000818:Animals; D017209:Apoptosis; D004195:Disease Models, Animal; D020287:In Situ Nick-End Labeling; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D010228:Paracoccidioides / Q000472:pathogenicity*; D010229:Paracoccidioidomycosis / Q000473:pathology*; D013950:Thymus Gland / Q000382:microbiology / Q000473:pathology* / Q000648:ultrastructure