RESUMO
We studied secreted-excreted immunogens in human patients infected with Trypanosoma cruzi. A pair of 45- to 55-kDa antigens and a family of shed acute-phase antigens characterized the acute phase, while antibodies against a 160- to 170-kDa immunogen appeared at the chronic phase of the disease.
Assuntos
Anticorpos Antiprotozoários/análise , Antígenos de Protozoários/análise , Doença de Chagas/imunologia , Trypanosoma cruzi/imunologia , Doença Aguda , Animais , Doença de Chagas/tratamento farmacológico , Doença Crônica , Eletroforese em Gel de Poliacrilamida , Humanos , Immunoblotting , Nitroimidazóis/uso terapêutico , Coelhos , Tripanossomicidas/uso terapêuticoRESUMO
The genes encoding a protein antigenic during the acute phase (SAPA) and another one antigenic during the chronic phase (antigen 30) of human Chagas' disease were analyzed in 15 Trypanosoma cruzi isolates and clones collected in distant geographical regions. These two genes had tandem repeats which were present in all parasites tested. However, large differences in the length of restriction fragments were observed among isolates. This was readily explained by variations in the number of repeat units present in homologous genes. This result was confirmed after analysis of 3 members of the SAPA gene family. In the case of antigen 30, we propose that differences in the number of repeat units result in size differences in the corresponding RNAs and proteins, which explains the large size heterogeneity in otherwise homologous T. cruzi antigens.