title: Successful Therapy of Murine Visceral Leishmaniasis with Astrakurkurone, a Triterpene Isolated from the Mushroom Astraeus hygrometricus, Involves the Induction of Protective Cell-Mediated Immunity and TLR9.
abstract: In our previous report, we showed that astrakurkurone, a triterpene isolated from the Indian mushroom Astraeus hygrometricus (Pers.) Morgan, induced reactive oxygen species, leading to apoptosis in Leishmania donovani promastigotes, and also was effective in inhibiting intracellular amastigotes at the 50% inhibitory concentration of 2.5 μg/ml. The aim of the present study is to characterize the associated immunomodulatory potentials and cellular activation provided by astrakurkurone, leading to effective antileishmanial activity in vitro and in vivo Astrakurkurone-mediated antileishmanial activity was evaluated by real-time PCR and flow cytometry. The involvement of Toll-like receptor 9 (TLR9) was studied by in vitro assay in the presence of a TLR9 agonist and antagonist and by in silico modeling of a three-dimensional structure of the ectodomain of TLR9 and its interaction with astrakurkurone. Astrakurkurone caused a significant increase in TLR9 expression of L. donovani-infected macrophages along with the activation of proinflammatory responses. The involvement of TLR9 in astrakurkurone-mediated amastigote killing has been evidenced from the fact that a TLR9 agonist (CpG, ODN 1826) in combination with astrakurkurone enhanced the amastigote killing, while a TLR9 antagonist (bafilomycin A1) alone or in combination with astrakurkurone curbed the amastigote killing, which could be further justified by in silico evidence of docking between mouse TLR9 and astrakurkurone. Astrakurkurone was found to reduce the parasite burden in vivo by inducing protective cytokines, gamma interferon and interleukin 17. Moreover, astrakurkurone was nontoxic toward peripheral blood mononuclear cells of immunocompromised patients with visceral leishmaniasis. Astrakurkurone, a nontoxic antileishmanial, enhances the immune efficiency of host cells, leading to parasite clearance in vitro and in vivo.
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors.forename: Suvadip
authors.initials: S
authors.lastname: Mallick
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors.forename: Aritri
authors.initials: A
authors.lastname: Dutta
authors.affiliation: Department of Microbiology, West Bengal State University, Barasat, West Bengal, India.
authors.forename: Ankur
authors.initials: A
authors.lastname: Chaudhuri
authors.affiliation: National Centre for Cell Science, Ganeshkhind, Pune, Maharashtra, India.
authors.forename: Debasri
authors.initials: D
authors.lastname: Mukherjee
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors.forename: Somaditya
authors.initials: S
authors.lastname: Dey
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India National Centre for Cell Science, Ganeshkhind, Pune, Maharashtra, India.
authors.forename: Subhadra
authors.initials: S
authors.lastname: Halder
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors.forename: Joydip
authors.initials: J
authors.lastname: Ghosh
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors.forename: Debarati
authors.initials: D
authors.lastname: Mukherjee
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors.forename: Sirin Salma
authors.initials: SS
authors.lastname: Sultana
authors.affiliation: Molecular and Applied Mycology and Plant Pathology Laboratory, Department of Botany, University of Calcutta, West Bengal, India.
authors.forename: Gunjan
authors.initials: G
authors.lastname: Biswas
authors.affiliation: Molecular and Applied Mycology and Plant Pathology Laboratory, Department of Botany, University of Calcutta, West Bengal, India.
authors.forename: Tapan Kumar
authors.initials: TK
authors.lastname: Lai
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India Canning Subdivisional Hospital, Canning, South 24 Parganas, West Bengal, India.
authors.forename: Pradyumna
authors.initials: P
authors.lastname: Patra
authors.affiliation: Canning Subdivisional Hospital, Canning, South 24 Parganas, West Bengal, India.
authors.forename: Indranil
authors.initials: I
authors.lastname: Sarkar
authors.affiliation: Department of Microbiology, West Bengal State University, Barasat, West Bengal, India.
authors.forename: Sibani
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: National Centre for Cell Science, Ganeshkhind, Pune, Maharashtra, India.
authors.forename: Bhaskar
authors.initials: B
authors.lastname: Saha
authors.affiliation: Molecular and Applied Mycology and Plant Pathology Laboratory, Department of Botany, University of Calcutta, West Bengal, India.
authors.forename: Krishnendu
authors.initials: K
authors.lastname: Acharya
authors.affiliation: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India cpcu.immunology@gmail.com.
authors.forename: Chiranjib
authors.initials: C
authors.lastname: Pal
mesh_terms: D000363:Agaricales / Q000737:chemistry; D000818:Animals; D000981:Antiprotozoal Agents / Q000276:immunology / Q000627:therapeutic use*; D015153:Blotting, Western; D005434:Flow Cytometry; D007111:Immunity, Cellular / Q000187:drug effects; D007898:Leishmaniasis, Visceral / Q000188:drug therapy* / Q000276:immunology*; D018942:Macrolides / Q000627:therapeutic use; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051217:Toll-Like Receptor 9 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014315:Triterpenes / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D000981:Antiprotozoal Agents; D018942:Macrolides; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D051217:Toll-Like Receptor 9; D014315:Triterpenes; C040929:bafilomycin A1