Re-circulation of lymphocytes mediated by sphingosine-1-phosphate receptor-1 contributes to resistance against experimental infection with the protozoan parasite Trypanosoma cruzi

Autor(es)

Dominguez, Mariana R. ^{[1, 2]} ; Ersching, Jonatan ^{[1, 2]} ; Lemos, Ramon ^{[1, 2]} ; Machado, Alexandre V. ^[3] ; Bruna-Romero, Oscar ^[4] ; Rodrigues, Mauricio M. ^{[1, 2]} ; de Vasconcelos, Jose Ronnie C. ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Escola Paulista Med, Sao Paulo - Brazil

^[2] Univ Fed Sao Paulo, Ctr Terapia Celular & Mol CTCMol, Escola Paulista Med, Sao Paulo - Brazil

^[3] Fiocruz MS, Ctr Pesquisas Rene Rachou, Belo Horizonte, MG - Brazil

^[4] Univ Fed Minas Gerais, Inst Ciencias Biol, Dept Microbiol, Belo Horizonte, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Vaccine; v. 30, n. 18, p. 2882-2891, APR 16 2012.
• Citações Web of Science: 12

Resumo

T-cell mediated immune responses are critical for acquired immunity against infection by the intracellular protozoan parasite Trypanosoma cruzi. Despite its importance, it is currently unknown where protective T cells are primed and whether they need to re-circulate in order to exert their anti-parasitic effector functions. Here, we show that after subcutaneous challenge, CD11c(+)-dependent specific CD8(+) T-cell immune response to immunodominant parasite epitopes arises almost simultaneously in the draining lymph node (LN) and the spleen. However, until day 10 after infection, we observed a clear upregulation of activation markers only on the surface of CD11C(+)PDCA1(+) cells present in the LN and not in the spleen. Therefore, we hypothesized that CD8(+) T cells re-circulated rapidly from the LN to the spleen. We investigated this phenomenon by administering FTY720 to T. cruzi-infected mice to prevent egress of T cells from the LN by interfering specifically with signalling through sphingosine-1-phosphate receptor-1. In T. cruzi-infected mice receiving FTY720, CD8 T-cell immune responses were higher in the draining LN and significantly reduced in their spleen. Most importantly, FTY720 increased susceptibility to infection, as indicated by elevated parasitemia and accelerated mortality. Similarly, administration of FTY720 to mice genetically vaccinated with an immunodominant parasite antigen significantly reduced their protective immunity, as observed by the parasitemia and survival of vaccinated mice. We concluded that re-circulation of lymphocytes mediated by sphingosine-1-phosphate receptor-1 greatly contributes to acquired and vaccine-induced protective immunity against experimental infection with a human protozoan parasite. (C) 2012 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 09/06820-4 - Caracterização das células apresentadoras de antígeno capazes de iniciar a reposta imune e controlar a imunodominância de Linfócitos T CD8+ específicos durante a infecção experimental pelo Trypanosoma cruzi
• Beneficiário: Maurício Martins Rodrigues
• Modalidade de apoio: Auxílio à Pesquisa - Regular