title: Whole-Killed Blood-Stage Vaccine-Induced Immunity Suppresses the Development of Malaria Parasites in Mosquitoes.
abstract: As a malaria transmission-blocking vaccine alone does not confer a direct benefit to the recipient, it is necessary to develop a vaccine that not only blocks malaria transmission but also protects vaccinated individuals. In this study we observed that a whole-killed blood-stage vaccine (WKV) not only conferred protection against the blood-stage challenge but also markedly inhibited the transmission of different strains of the malaria parasite. Although the parasitemia is much lower in WKV-immunized mice challenged with malaria parasites, the gametocytemia is comparable between control and immunized mice during the early stages of infection. The depletion of CD4+T cells prior to the adoptive transfer of parasites into WKV-immunized mice has no effect on the development of the malaria parasite in the mosquito, but the adoptive transfer of the serum from the immunized mice into the parasite-inoculated mice remarkably suppresses the development of malaria parasites in mosquitoes. Furthermore, immunized mice challenged with the malaria parasite generate higher levels of parasite-specific Abs and the inflammatory cytokines MCP-1 and IFN-γ. However, the adoptive transfer of parasite-specific IgG or the depletion of MCP-1, but not IFN-γ, to some extent is closely associated with the suppression of malaria parasite development in mosquitoes. These data strongly suggest that WKV-induced immune responses confer protection against the mosquito stage, which is largely dependent on malaria parasite-specific Abs and MCP-1. This finding sheds new light on blocking malaria transmission through the immunization of individuals with the WKV.
authors.affiliation: Department of Pathogenic Biology, Third Military Medical University, Chongqing 400038, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.affiliation: Department of Pathogenic Biology, Third Military Medical University, Chongqing 400038, People's Republic of China.
authors.forename: Taiping
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Pathogenic Biology, Third Military Medical University, Chongqing 400038, People's Republic of China.
authors.forename: Chenhao
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Department of Pathogenic Biology, Third Military Medical University, Chongqing 400038, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Pathogenic Biology, Third Military Medical University, Chongqing 400038, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Pathogenic Biology, Third Military Medical University, Chongqing 400038, People's Republic of China xuwenyue@gmail.com.
authors.forename: Wenyue
authors.identifier: 0000-0003-3681-5052
authors.initials: W
authors.lastname: Xu
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D009033:Culicidae / Q000469:parasitology*; D008018:Life Cycle Stages / Q000187:drug effects; D008288:Malaria / Q000517:prevention & control* / Q000635:transmission*; D017780:Malaria Vaccines / Q000276:immunology* / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010967:Plasmodium yoelii / Q000187:drug effects / Q000254:growth & development / Q000276:immunology; D015164:Vaccines, Inactivated / Q000276:immunology / Q000494:pharmacology
chemical_list: D000913:Antibodies, Protozoan; D017780:Malaria Vaccines; D015164:Vaccines, Inactivated