Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/10908
Title: NK1.1 cells are required to control T cell hyperactivity during Trypanosoma cruzi infection.
Authors: Cardillo, Fabíola
Nomizo, Auro
Postól, Edilberto
Mengele Junior, José Orivaldo
Affilliation: University of São Paulo. Institute for Biomedical Sciences IV. Department of Immunology. São Paulo, SP, Brasil / University of São Paulo. Department of Clinical Analysis. São Paulo, SP, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Laboratório de Doença Experimental de Chagas, Imunologia Celular e Auto-imunidade. Salvador, BA, Brasil
University of São Paulo. Department of Clinical Analysis. São Paulo, SP, Brasil
University of São Paulo. Institute for Biomedical Sciences IV. Department of Immunology. São Paulo, SP, Brasil
University of São Paulo. Institute for Biomedical Sciences IV. Department of Immunology. São Paulo, SP, Brasil / University of São Paulo. Department of Clinical Analysis. São Paulo, SP, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Laboratório de Doença Experimental de Chagas, Imunologia Celular e Auto-imunidade. Salvador, BA, Brasil
Abstract: BACKGROUND: This study evaluated the regulatory function of NK1.1+ cells during Trypanosoma cruzi infection. MATERIAL/METHODS: Both thymectomized (Tx C57Bl/6) and euthymic C57Bl/6 mice (C57Bl/6) were infected intraperitoneally with the Tulahuen strain. NK1.1+ cells were depleted in vivo by anti-NK1.1 mAb. Spleen cells were analyzed by flow cytometry for the expression of CD44 and CD69 on T cells. Supernatants from splenocytes were used to measure nitrite concentration (quantified by Griess reagent). Interleukin 2 and IFN-gamma levels were determined by ELISA. The protocols used herein were approved by the Institutional Committee for Ethics. Student's t or Kruskal-Wallis tests were applied, as indicated. RESULTS: The number of T cells expressing CD69 increased progressively during T. cruzi infection in NK1.1 cell-depleted C57Bl/6 mice. In spite of an increased early T cell activation during infection, the percentage of CD4+ CD44high T cells did not augment in NK1.1 cell-depleted C57Bl/6 mice compared with untreated C57Bl/6 controls. Serum levels of IFN-gamma in anti-NK1.1-treated mice were higher than in non-depleted animals. Con-A-stimulated spleen cell supernatants from NK1.1 cell-depleted animals contained increased levels of IL-2 and nitric oxide (NO) during early infection. CONCLUSIONS: After the first week of infection, NO overproduction and high levels of IFN-gamma in anti-NK1.1-tre-ated C57Bl/6 mice appeared to be related to susceptibility and hyperactivation of peripheral T cells. Finally, this study suggests a novel regulatory function of NK1.1+ cells during T. cruzi infection. Without NK1.1 cells, T lymphocytes are hyperactivated but do not differentiate to effector/memory T cells in infected C57Bl/6 mice.
Keywords: T. cruzi
NK1.1 T cells
Regulatory cells
IFN-gamma
Nitric oxide
Interleukin-2
DeCS: Antígenos CD44/metabolismo
Antígenos de Diferenciação de Linfócitos T/metabolismo
Células Matadoras Naturais/imunologia
Baço/imunologia
Linfócitos T/imunologia
Animais
Citometria de Fluxo
Interferon gama/metabolismo
Interleucina-2/metabolismo
Lectinas Tipo C
Camundongos
Camundongos Endogâmicos C57BL
Óxido Nítrico/metabolismo
Baço/parasitologia
Trypanosoma cruzi/imunologia
Issue Date: 2004
Publisher: Medical Science International Publishing
Citation: CARDILLO, F. et al. NK1.1 cells are required to control T cell hyperactivity during Trypanosoma cruzi infection. Medical Science Monitor, v. 10, n. 8, p. BR259-267, 2004.
ISSN: 1234-1010
Copyright: open access
Appears in Collections:BA - IGM - Artigos de Periódicos

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