RESUMO
This study examined the seroprevalence and serum antibody isotype profile for Taenia solium cysticercosis in an Amerindian community in the Amazonas state of Venezuela. An antigen-trapping enzyme-linked immunosorbent assay (Ag-ELISA) was used to detect viable cysticercosis. Indirect ELISA (Ab-ELISA) and enzyme-linked immunoelectrotransfer blot (EITB) was performed by using antigens prepared from T. solium metacestodes to detect anti-parasite antibodies. The Ag-ELISA and Ab-ELISAs revealed 64.7% and 79.0% seropositivity, respectively, in the Amerindian population. Immunoglobulin (Ig) M was the predominant antibody class, suggesting recent infection. In comparison sera from, clinically defined, hospital neurocysticercosis cases revealed only 27% seropositivity by Ag-ELISA, compared with 86-92% seropositivity by Ab-ELISA, and IgG4 was the predominant antibody subclass detected. The EITB antigen recognition patterns of the hospitalized patients were very similar to that of the Amerindians, confirming exposure to the parasite. These results, combined with the predominance of IgM antibody responses and the marked detection of secreted products of viable parasites, strongly suggest that recent exposure to T. solium had occurred in the Amerindian population.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Cisticercose/epidemiologia , Taenia/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Cisticercose/etiologia , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Immunoblotting , Indígenas Sul-Americanos , Masculino , Neurocisticercose/epidemiologia , Neurocisticercose/etiologia , Estudos Soroepidemiológicos , Taenia/isolamento & purificação , Venezuela/epidemiologiaRESUMO
The transfer of spleen cells from (BALB/c x C57Bl/6) F1 mice recovered from a Plasmodium chabaudi chabaudi AS infection into irradiated syngeneic recipients conferred protection. Neither elimination of Thy-1+ cells nor in vitro irradiation of immune cells before transfer affected protection while both anti-Thy-1 treatment and irradiation abolished the appearance of anti-P. c. chabaudi antibodies in the recipients. Superinfection of immune spleen cell donors did not improve their capability to transfer protection which was also unaffected by anti-Thy-1 treatment. The serum of mice after one infection was only marginally protective when transferred into irradiated recipients and a second infection improved the protective activity of serum which was not further improved by six infections. The co-transfer of immune serum and immune cells did not result in any synergistic effect. On the other hand, when P. c. chabaudi AS (BALB/c x C57Bl/6) F1 infected mice were challenged with a high dose of Plasmodium yoelii 17XL at crisis, the mice were unable to control the heterologous parasite. When mice were challenged with P. yoelii 17XL several weeks after infection with P. c. chabaudi AS, a good degree of cross-protection was observed.