Lack of evidence for superantigen activity of Toxoplasma gondii towards human T cells

Lack of evidence for superantigen activity of Toxoplasma gondii towards human T cells

Autor Vallochi, A.l. Google Scholar
Yamamoto, J.h. Google Scholar
Schlesinger, D. Google Scholar
Machado, M.a.c. Google Scholar
Silveira, C. Autor UNIFESP Google Scholar
Martins, M.c. Autor UNIFESP Google Scholar
Belfort, Rubens Junior Autor UNIFESP Google Scholar
Kalil, J. Google Scholar
Rizzo, Luiz Vicente Google Scholar
Instituição Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
Fundação E.J. Zerbini
Resumo Toxoplasma gondii is an obligatory intracellular parasite whose life cycle may include man as an intermediate host. More than 500 million people are infected with this parasite worldwide. It has been previously reported that T. gondii contains a superantigen activity. The purpose of the present study was to determine if the putative superantigen activity of T. gondii would manifest towards human T cells. Peripheral blood mononuclear cells (PBMC) from individuals with no previous contact with the parasite were evaluated for proliferation as well as specific Vß expansion after exposure to Toxoplasma antigens. Likewise, PBMC from individuals with the congenital infection were evaluated for putative Vß family deletions in their T cell repertoire. We also evaluated, over a period of one year, the PBMC proliferation pattern in response to Toxoplasma antigens in patients with recently acquired infection. Some degree of proliferation in response to T. gondii was observed in the PBMC from individuals never exposed to the parasite, accompanied by specific Vß expansion, suggesting a superantigen effect. However, we found no specific deletion of Vß (or Valpha) families in the blood of congenitally infected individuals. Furthermore, PBMC from recently infected individuals followed up over a period of one year did not present a reduction of the Vß families that were originally expanded in response to the parasite antigens. Taken together, our data suggest that T. gondii does not have a strong superantigen activity on human T cells.
Palavra-chave Toxoplasma
tolerance
superantigen
T cell receptor
Idioma Inglês
Data de publicação 2001-08-01
Publicado em Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 34, n. 8, p. 1023-1031, 2001.
ISSN 0100-879X (Sherpa/Romeo)
Publicador Associação Brasileira de Divulgação Científica
Extensão 1023-1031
Fonte http://dx.doi.org/10.1590/S0100-879X2001000800008
Direito de acesso Acesso aberto Open Access
Tipo Artigo
SciELO S0100-879X2001000800008 (estatísticas na SciELO)
Endereço permanente http://repositorio.unifesp.br/handle/11600/1225

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