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Leishmaniasis is a major public infectious disease caused by the genus Leishmania. No effective drug or vaccination strategy for leishmaniasis has been designed yet. Several intracellular Leishmania antigens have been recognized to serve in vaccination, ensuring long-lasting protection against Leishmania infection. Lipophosphoglican 3 (LPG3) as a member of the heat shock protein 90 family involves in the synthesis of lipophosphoglycan (LPG) and implicates in parasite virulence. Regarding the immunological properties of LPG3 particularly its N-terminal fragment, it would be considered as a favourable adjuvant in Leishmania vaccination., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Background: Natural killer (NK) cells play an important role in early stages of innate immune responses against viral and tumoral attacks. Activation of NK cells by leishmaniasis results in secretion of cytokines such as interferon (IFN)-γ and tumor necrosis factor (TNF)-α, which enhances the phagocytosis and clear­ance of parasite. Lipophosphoglycan 3 (LPG3), the Leishmania homologous with GRP94 (glucose regulated protein 94), a member of HSP90 family, contributes to LPG assembly as the most abundant macromolecule on the surface of Leishmania promastigotes. Methods: We purified NK cells from healthy individuals (n=10) using magnetic-activated cell sorting (MACS) technology. Purified NK cells were co-incubated with different concentrations of recombinant LPG3 (rLPG3), and its N-terminal (NT) and C-terminal (CT) fragments. Finally, the production of IFN-γ and TNF-α by NK cells were measured by ELISA. Results: Recombinant LPG3 but not its fragments (CT and NT), can signifi­cantly enhance the production of TNF-α by NK cells (P

Background: Natural killer (NK) cells play an important role in early stages of innate immune responses against viral and tumoral attacks. Activation of NK cells by leishmaniasis results in secretion of cytokines such as interferon (IFN)-γ and tumor necrosis factor (TNF)-α, which enhances the phagocytosis and clearance of parasite. Lipophosphoglycan 3 (LPG3), the Leishmania homologous with GRP94 (glucose regulated protein 94), a member of HSP90 family, contributes to LPG assembly as the most abundant macromolecule on the surface of Leishmania promastigotes. Methods: We purified NK cells from healthy individuals (n=10) using magneticactivated cell sorting (MACS) technology. Purified NK cells were co-incubated with different concentrations of recombinant LPG3 (rLPG3), and its N-terminal (NT) and C-terminal (CT) fragments. Finally, the production of IFN-γ and TNF- α by NK cells were measured by ELISA. Results: Recombinant LPG3 but not its fragments (CT and NT), can significantly enhance the production of TNF-α by NK cells (P<0.05). Moreover, rLPG3, CT, and NT fragments were markedly stimulated the secretion of IFN-γ by NK cells (P<0.001). Conclusion: The Leishmania LPG3 antigen can effectively activate NK cells, in vitro. Leishmania LPG3 participates in the innate immunity against leishmaniasis and thereby improves the effective parasite destruction. However, its efficiency should be tested in vivo. [ABSTRACT FROM AUTHOR]