Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 10 4 2015 12 14 554 560 EN Sanaz RASOLZADEH Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Dept. of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Mostafa HAJI FATAHALIHA Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Dept. of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Maryam HOSSEINI Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Dept. of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Reza JAFARI Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Dept. of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Abolfazl MIAHIPOUR Dept. of Medical Parasitology and Mycology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran Ali Akbar MOVASSAGHPOUR Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Dept. of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Zohreh BABALO Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Dept. of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Sima RAFATI Molecular Immunology and Vaccine Research Lab, Pasteur Institute of Iran, Tehran, Iran Mehdi YOUSEFI Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Dept. of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran 2015 12 14 2015 12 14 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<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. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/654 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/654/535