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

Author 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
Institution Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
Fundação E.J. Zerbini
Abstract 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.
Keywords Toxoplasma
tolerance
superantigen
T cell receptor
Language English
Date 2001-08-01
Published in 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)
Publisher Associação Brasileira de Divulgação Científica
Extent 1023-1031
Origin http://dx.doi.org/10.1590/S0100-879X2001000800008
Access rights Open access Open Access
Type Article
SciELO ID S0100-879X2001000800008 (statistics in SciELO)
URI http://repositorio.unifesp.br/handle/11600/1225

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