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Please use this identifier to cite or link to this item: https://repositorio.ufba.br/handle/ri/13738
metadata.dc.type: Artigo de Periódico
Title: Dual effect of Lutzomyia longipalpis saliva on Leishmania braziliensis infection is mediated by distinct saliva-induced cellular recruitment into BALB/c mice ear
Other Titles: BMC Microbiology
Authors: Carregaro, Vanessa
Costa, Diego Luis
Brodskyn, Claudia Ida
Barral, Aldina Maria Prado
Barral-Netto, Manoel
Cunha, Fernando Q
Silva, João Santana
metadata.dc.creator: Carregaro, Vanessa
Costa, Diego Luis
Brodskyn, Claudia Ida
Barral, Aldina Maria Prado
Barral-Netto, Manoel
Cunha, Fernando Q
Silva, João Santana
Abstract: Background: Leishmania parasites are transmitted to their vertebrate hosts by infected Phlebotomine sand flies during the blood meal of the flies. Sand fly saliva is known to enhance Leishmania spp. infection, while preexposure to saliva protects mice against parasitic infections. In this study, we investigated the initial inflammatory leucocyte composition induced by one or three inocula of salivary gland extract (SGE) from Lutzomyia longipalpis in the presence or absence of Leishmania braziliensis. Results: We demonstrated that inoculating SGE once (SGE-1X) or three times (SGE-3X), which represented a coinoculation or a pre-exposure to saliva, respectively, resulted in different cellular infiltrate profiles. Whereas SGE-1X led to the recruitment of all leucocytes subtypes including CD4+ T cells, CD4+CD25+ T cells, dendritic cells, macrophages and neutrophils, the immune cell profile in the SGE-3X group differed dramatically, as CD4+ T cells, CD4+CD25+ T cells, dendritic cells, macrophages and neutrophils were decreased and CD8+ T cells were increased. The SGE-1X group did not show differences in the ear lesion size; however, the SGE-1X group harbored a higher number of parasites. On the other hand, the SGE-3X group demonstrated a protective effect against parasitic disease, as the parasite burden was lower even in the earlier stages of the infection, a period in which the SGE-1X group presented with larger and more severe lesions. These effects were also reflected in the cytokine profiles of both groups. Whereas the SGE-1X group presented with a substantial increase in IL-10 production, the SGE-3X group showed an increase in IFN-γ production in the draining lymph nodes. Analysis of the inflammatory cell populations present within the ear lesions, the SGE-1X group showed an increase in CD4+FOXP3+ cells, whereas the CD4+FOXP3+ population was reduced in the SGE-3X group. Moreover, CD4+ T cells and CD8+ T cells producing IFN-γ were highly detected in the ears of the SGE-3X mice prior to infection. In addition, upon treatment of SGE-3X mice with anti-IFN-γ monoclonal antibody, we observed a decrease in the protective effect of SGE-3X against L. braziliensis infection. Conclusions: These results indicate that different inocula of Lutzomyia longipalpis salivary gland extract can markedly modify the cellular immune response, which is reflected in the pattern of susceptibility or resistance to Leishmania braziliensis infection.
Keywords: Phlebotomines saliva
Lutzomyia longipalpis saliva
Leishmania braziliensis
Inflammatory leucocytes
Cytokines
Immunoregulation
Publisher: BMC Microbiology
metadata.dc.rights: Acesso Aberto
URI: http://repositorio.ufba.br/ri/handle/ri/13738
Issue Date: 2013
Appears in Collections:Artigo Publicado em Periódico (Faculdade de Medicina)

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