Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/7257
Title: The presence of Tregs does not preclude immunity to reinfection with Leishmania braziliensis
Authors: Falcão, Sarah de Athayde Couto
Moura, Tatiana Rodrigues de
Clarêncio, Jorge
Brodskyn, Claudia Ida
Barral, Aldina Maria Prado
Oliveira, Camila Indiani de
Affilliation: Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, Brasil / Instituto de Investigação em Imunologia. Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, Brasil / Instituto de Investigação em Imunologia. Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Instituto de Investigação em Imunologia. Brasil
Abstract: Leishmania spp. cause a broad spectrum of diseases collectively known as leishmaniasis. Leishmania braziliensis is the main etiological agent of American cutaneous leishmaniasis and mucocutaneous leishmaniasis. During experimental infection with L. braziliensis, BALB/c mice develop an adaptive immune response that is associated with lesion healing and, in parallel, parasite persistence within draining lymph nodes (dLNs). In the Leishmania major model of cutaneous leishmaniasis, regulatory T cells (Tregs) play an important role in immune regulation, preventing pathological immune responses but at the same time precluding sterile cure. In this study we investigated the role of Tregs during experimental infection with L. braziliensis. CD4+CD25+ T cells were detected throughout the duration of clinical disease both at the ear and in dLNs of infected mice. These cells expressed Treg markers such as glucocorticoid-induced TNF-receptor-related protein (GITR), the a chain of the aeb7 integrin (CD103), and the forkhead/winged helix transcription factor, Foxp3, and were able to suppress the proliferation of CD4+CD25 cells. Importantly, a high frequency of Foxp3+ cells accumulated at the site of infection and in dLNs. We next investigated the outcome of a reinfection with L. braziliensis in terms of Treg distribution and disease reactivation. Interestingly, a secondary inoculation with L. braziliensis did not preclude an efficient recall response to L. braziliensis at a distal site, despite the presence of Tregs. Within dLNs, reinfection did not promote parasite dissemination or a differential recruitment of either CD4+CD25+Foxp3+ or CD4+IL-10+ T cells. On the contrary, parasites were mainly detected in the LN draining the primary infection site where a high frequency of CD4+IFN-c+ T cells was also present. Collectively these data show that during experimental infection, Tregs are present in healed mice but this population does not compromise an effective immune response upon reinfection with L. braziliensis.
Keywords: Leishmania braziliensis
Treg
CD4+CD25+
Issue Date: 2012
Publisher: Elsevier Ltd
Citation: FALCÃO, S. C. et al. The presence of Tregs does not preclude immunity to reinfection with Leishmania braziliensis. International Journal of Parasitology, v.42, n. 8, p.771-780, 2012.
DOI: http://dx.doi.org/10.1016/j.ijpara.2012.05.006
ISSN: 0020-7519
Copyright: open access
Appears in Collections:BA - IGM - Artigos de Periódicos

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