title: CD8+ T cells eliminate liver-stage Plasmodium berghei parasites without detectable bystander effect.
abstract: Immunization with attenuated Plasmodium sporozoites or viral vectored vaccines can induce protective CD8(+) T cells that can find and eliminate liver-stage malaria parasites. A key question is whether CD8(+) T cells must recognize and eliminate each parasite in the liver or whether bystander killing can occur. To test this, we transferred antigen-specific effector CD8(+) T cells to mice that were then coinfected with two Plasmodium berghei strains, only one of which could be recognized directly by the transferred T cells. We found that the noncognate parasites developed normally in these mice, demonstrating that bystander killing of parasites does not occur during the CD8(+) T cell response to malaria parasites. Rather, elimination of infected parasites is likely mediated by direct recognition of infected hepatocytes by antigen-specific CD8(+) T cells.
authors.affiliation: Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Cockburn
authors.forename: Sze-Wah
authors.initials: SW
authors.lastname: Tse
authors.forename: Fidel
authors.initials: F
authors.lastname: Zavala
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D024201:Bystander Effect / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology*; D022781:Hepatocytes / Q000469:parasitology*; D008099:Liver / Q000469:parasitology; D008288:Malaria / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D059208:Parasite Load; D010962:Plasmodium berghei / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan