RESUMO
Major histocompatibility complex (MHC) class II molecules have an integral role in the adaptive immune response, as they bind and present antigenic peptides to T helper lymphocytes. In this study of koalas, species-specific primers were designed to amplify exon 2 of the MHC class II DA and DB genes, which contain much of the peptide-binding regions of the α and ß chains. A total of two DA α1 domain variants and eight DA ß1 (DAB), three DB α1 and five DB ß1 variants were amplified from 20 koalas from two free-living populations from South East Queensland and the Port Macquarie region in northern New South Wales. We detected greater variation in the ß1 than in the α1 domains as well as evidence of positive selection in DAB. The present study provides a springboard to future investigation of the role of MHC in disease susceptibility in koalas.
Assuntos
Genes MHC da Classe II , Phascolarctidae/genética , Phascolarctidae/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Sequência de Aminoácidos , Animais , Infecções por Chlamydophila/imunologia , Infecções por Chlamydophila/veterinária , Primers do DNA , Amplificação de Genes , Variação Genética , Genótipo , Antígenos de Histocompatibilidade Classe II/química , Dados de Sequência Molecular , Filogenia , Alinhamento de SequênciaRESUMO
Cryptococcosis caused by Cryptococcus gattii is a devastating disease of immunocompetent hosts with an incompletely understood pathogenesis. Utilizing an immunoproteomic approach in a naturally occurring koala model of disease, a number of key proteins and pathways are identified in the early and late pathogenesis of cryptococcosis for the first time. In particular, the thioredoxin system appears important in the pathogenesis of cryptococcosis caused by C. gattii VGII.
Assuntos
Anticorpos Antifúngicos/imunologia , Antígenos de Fungos/isolamento & purificação , Criptococose/fisiopatologia , Cryptococcus gattii/imunologia , Phascolarctidae/microbiologia , Proteômica/métodos , Animais , Anticorpos Antifúngicos/sangue , Antígenos de Fungos/imunologia , Austrália , Criptococose/imunologia , Cryptococcus gattii/genética , Eletroforese em Gel Bidimensional , Immunoblotting , Phascolarctidae/imunologiaRESUMO
BACKGROUND: Leptospirosis is an important public health threat in sub-Saharan Africa but little is known regarding the host spectrum and epidemiology of this zoonotic disease. METHODS: 289 kidney samples from 69 wild, domestic and peri-domestic species in northern Botswana were screened for the presence of Leptospira sp. RESULTS: Renal carriage was widespread among mammals (31.4%, n=11/35 species), birds (27.8%, n=5/18 species) and reptiles (6.3%, n=1/16 species), including several novel species. CONCLUSION: Leptospiral surveillance is often limited to the usual suspects: rodents and domestic animals. We identify Leptospira in a wide range of African wildlife, suggesting that leptospirosis transmission and persistence may also involve hosts not normally considered.