![]() papatasi saliva resulted in protection which was not ascribed to a humoral immune response. Further experiments demonstrated that immunization with PpSP15 (gi|15963509) from P. This protective effect correlated with a strong delayed-type hypersensitivity (DTH) response and an early and increased in situ production of IFN-γ and IL-12. In mice, pre-exposure to saliva completely abrogated the effects of the sand fly saliva and protected the host from disease progression. Alternatively, it could be ascribed to the development of an adaptive immune response that would favor the commitment of a Th2 immunity against Leishmania. The exacerbating effects of saliva may also be related to the early release of epidermal interleukin-4 (IL-4). ![]() Sand fly saliva contains potent antihemostatic and vasodilatator compounds as well as potentially immunomodulatory molecules that can directly down-modulate macrophage effector functions and facilitate the establishment of the infection. The mechanism by which the vector's saliva enhances leishmania infection remains to be clarified. Several observations indicate that sand fly saliva is crucial in the establishment of leishmaniasis and disease pathogenesis –. During parasite inoculation in the host's skin, the vector injects the saliva that contains a large number of pharmacological components –. Leishmania parasites are transmitted to the vertebrate hosts by the bite of sand flies. The disease ranges from asymptomatic infections to self-limiting cutaneous lesion(s) or fatal visceral forms. Leishmaniasis includes a heterogeneous group of diseases that are caused by protozoan parasites of the genus Leishmania. ![]() The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Ĭompeting interests: The authors have declared that no competing interests exist. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.įunding: The project described was supported by the NIH/NIAID Grant Number SP50AI074178. Received: ApAccepted: AugPublished: October 4, 2011Ĭopyright: © 2011 Abdeladhim et al. PLoS Negl Trop Dis 5(10):Įditor: Paul Andrew Bates, Lancaster University, United Kingdom (2011) Human Cellular Immune Response to the Saliva of Phlebotomus papatasi Is Mediated by IL-10-Producing CD8+ T Cells and Th1-Polarized CD4+ Lymphocytes. The latter finding highlights the importance of the identification of the proteins activating the latter lymphocytes in order to develop vaccines based on selected proteins from the saliva of sand flies.Ĭitation: Abdeladhim M, Ben Ahmed M, Marzouki S, Belhadj Hmida N, Boussoffara T, Belhaj Hamida N, et al. Further experiments revealed that the production of IL-10 masked the presence of a second kind of lymphocytes producing IFN-γ, a rather protective cytokine. These data may preclude the protective effect of sand fly saliva pre-exposure in humans. We demonstrated that the immunity against saliva is dominated by the activation of lymphocytes producing a suppressive cytokine called IL-10. Herein we investigated the nature and the importance of the cellular immune response developed against sand fly saliva by individuals at risk of cutaneous leishmaniasis due to Leishmania major. ![]() Data obtained in mice originally indicate that immunization against saliva protected from leishmaniasis supporting possibility that leishmaniasis could be prevented by a vaccine based on sand fly saliva. Sand fly saliva contains several components that increase hemorrhage and interfere with the host's inflammatory response. While probing the skin for a blood meal, vectors salivate into the host's skin. The parasite is transmitted during sand fly bites. Cutaneous leishmaniasis affects millions of people worldwide and is caused by protozoa of the genus Leishmania.
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