Vaccinating mice against Maxidilan (MAX), the potent salivary vasodilatador from Lutzomyia longipalpis sand fly, protected the animal from L. major infection by eliciting anti-MAX antibodies and a Th1 immune response [14]. Moreover, mice inoculated with a 15-kDa salivary protein (PpSP15) produced a strong DTH response, which even occurred

in B cell knockout mice, suggesting that the cellular immune response against the saliva provided most, if not all, of the protective effect [16]. However, the mechanism responsible for the saliva-induced dual immunity observed in Leishmania infections remains unknown. Cell recruitment is E7080 cell line a vital event during inflammation. The cell number

and cellular composition soon after an inflammatory stimulus is encountered greatly influences the future responses and the development of an adaptive immune response. Leukocyte recruitment to infected tissue is a crucial event for the control of infections such as leishmaniasis [17, 18]. Furthermore, clinical leishmaniasis lesions are associated with an influx of inflammatory cells [19]. Sand fly saliva contains a mixture of pharmacologically active compounds that influence leucocyte migration. Phlebotomus dubosqi saliva attracts vertebrate monocytes in vitro[20] and P. papatasi saliva attracts macrophages and enhances infections by Leishmania donovani resulting in an increased parasitic load [21]. Lutzomyia longipalpis and P. papatasi saliva recruit eosinophils and macrophages through the release CP673451 manufacturer of Th2 cytokines and chemokines [13, 17, 18]. Neutrophils are recruited to the site of Leishmania Ketotifen inoculation during the bite of an infected sand fly and prevent parasite surveillance via oxidant- and protease-dependent mechanisms [22]. The co-injection of L. major with Lutzomyia longipalpis saliva increases the ON-01910 in vitro number of CD4+CD45RBlow T cells within the inoculation

site. Undoubtedly, sand fly saliva directly influences the recruitment of leucocytes by altering the adaptive immune response. In the current study, we characterized the distinct cellular composition within BALB/c mouse ears following the inoculation of salivary gland extract (SGE) from Lutzomyia longipalpis in association with distinct patterns of resistance or susceptibility to L. braziliensis infection. Methods Mice Male BALB/c mice weighing 18–22 g were housed in temperature-controlled rooms (22-25°C) with ad libitum access to water and food in the animal facility of the Department of Immunology, School of Medicine of Ribeirão Preto, University of São Paulo (Brazil). All experiments were conducted in accordance with NIH guidelines on the welfare of experimental animals, and all experiments were approved by the Ribeirão Preto School of Medicine Ethics Committee.