title: Splenic CD11c+ cells derived from semi-immune mice protect naïve mice against experimental cerebral malaria.
abstract: BACKGROUND
  Immunity to malaria requires innate, adaptive immune responses and Plasmodium-specific memory cells. Previously, mice semi-immune to malaria was developed. Three cycles of infection and cure ('three-cure') were required to protect mice against Plasmodium berghei (ANKA strain) infection.
  
  
  METHODS
  C57BL/6 J mice underwent three cycles of P. berghei infection and drug-cure to become semi-immune. The spleens of infected semi-immune mice were collected for flow cytometry analysis. CD11c(+) cells of semi-immune mice were isolated and transferred into naïve mice which were subsequently challenged and followed up by survival and parasitaemia.
  
  
  RESULTS
  The percentages of splenic CD4(+) and CD11c(+) cells were increased in semi-immune mice on day 7 post-infection. The proportion and number of B220(+)CD11c(+)low cells (plasmacytoid dendritic cells, DCs) was higher in semi-immune, three-cure mice than in their naïve littermates on day 7 post-infection (2.6 vs 1.1% and 491,031 vs 149,699, respectively). In adoptive transfer experiment, three months after the third cured P. berghei infection, splenic CD11c(+) DCs of non-infected, semi-immune, three-cure mice slowed Plasmodium proliferation and decreased the death rate due to neurological pathology in recipient mice. In addition, anti-P. berghei IgG1 level was higher in mice transferred with CD11c(+) cells of semi-immune, three-cure mice than mice transferred with CD11c(+) cells of naïve counterparts.
  
  
  CONCLUSIONS
  CD11c(+) cells of semi-immune mice protect against experimental cerebral malaria three months after the third cured malaria, potentially through protective plasmacytoid DCs and enhanced production of malaria-specific antibody.
authors: Department of Immunogenetics, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan. lamquocbao@nagasaki-u.ac.jp.
authors: Lam Q
authors: LQ
authors: Bao
authors: Dang M
authors: DM
authors: Nhi
authors: Nguyen T
authors: NT
authors: Huy
authors: Mihoko
authors: M
authors: Kikuchi
authors: Tetsuo
authors: T
authors: Yanagi
authors: Shinjiro
authors: S
authors: Hamano
authors: Kenji
authors: K
authors: Hirayama
mesh_terms: D000818:Animals; D039521:CD11c Antigen / Q000032:analysis*; D004195:Disease Models, Animal; D005434:Flow Cytometry; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D016779:Malaria, Cerebral / Q000276:immunology* / Q000517:prevention & control*; D008810:Mice, Inbred C57BL; D018512:Parasitemia / Q000517:prevention & control; D010962:Plasmodium berghei / Q000276:immunology*; D013154:Spleen / Q000276:immunology*; D016019:Survival Analysis
chemical_list: D039521:CD11c Antigen
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