title: Studies on the protective efficacy of freeze thawed promastigote antigen of Leishmania donovani along with various adjuvants against visceral leishmaniasis infection in mice.
abstract: Visceral leishmaniasis (VL) caused by Leishmania donovani persists as a major public health issue in tropical and subtropical areas of the world. Current treatment of this disease relies on use of drugs. It is doubtful that chemotherapy can alone eradicate the disease, so there is a need for an effective vaccine. Killed antigen candidates remain a good prospect considering their ease of formulation, stability, low cost and safety. To enhance the efficacy of killed vaccines suitable adjuvant and delivery system are needed. Therefore, the current study was conducted to determine the protective efficacy of freeze-thawed L. donovani antigen in combination with different adjuvants against experimental infection of VL. For this, BALB/c mice were immunized thrice at an interval of two weeks. Challenge infection was given two weeks after last immunization. Mice were sacrificed after last immunization and on different post challenge/infection days. Immunized mice showed significant reduction in parasite burden, enhanced DTH responses with increased levels of Th1 cytokines and lower levels of Th2 cytokines, thus indicating the development of a protective Th1 response. Maximum protection was achieved with liposome encapsulated freeze thawed promastigote (FTP) antigen of L. donovani and it was followed by group immunized with FTP+MPL-A, FTP+saponin, FTP+alum and FTP antigen (alone). The present study highlights greater efficacy of freeze thawed promastigote antigen as a potential vaccine candidate along with effective adjuvant formulations against experimental VL infection.
authors.affiliation: Department of Zoology, Panjab University, Chandigarh 160014, India.
authors.forename: Ankita
authors.initials: A
authors.lastname: Thakur
authors.affiliation: Department of Zoology, Panjab University, Chandigarh 160014, India.
authors.forename: Harpreet
authors.initials: H
authors.lastname: Kaur
authors.affiliation: Department of Zoology, Panjab University, Chandigarh 160014, India. Electronic address: puzoology@yahoo.com.
authors.forename: Sukhbir
authors.initials: S
authors.lastname: Kaur
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology*; D016207:Cytokines / Q000097:blood; D005260:Female; D005615:Freezing; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007893:Leishmania donovani / Q000276:immunology*; D054332:Leishmaniasis Vaccines / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D059208:Parasite Load; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014611:Vaccination; D015164:Vaccines, Inactivated / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016207:Cytokines; D007074:Immunoglobulin G; D054332:Leishmaniasis Vaccines; D015164:Vaccines, Inactivated
keywords: Adjuvants; Freeze thawed promastigote (FTP); Immune response; Killed vaccines; Visceral leishmaniasis