title: Malaria protection in beta 2-microglobulin-deficient mice lacking major histocompatibility complex class I antigens: essential role of innate immunity, including gammadelta T cells.
abstract: It is still controversial whether malaria protection is mediated by conventional immunity associated with T and B cells or by innate immunity associated with extrathymic T cells and autoantibody-producing B cells. Given this situation, it is important to examine the mechanism of malaria protection in beta(2)-microglobulin-deficient (beta(2)m(-/-)) mice. These mice lack major histocompatibility complex class I and CD1d antigens, which results in the absence of CD8(+) T cells and natural killer T (NKT) cells. When C57BL/6 and beta(2)m(-/-) mice were injected with parasitized (Plasmodium yoelii 17XNL) erythrocytes, both survived from the infection and showed a similar level of parasitaemia. The major expanding T cells were NK1.1(-) alphabeta T-cell receptor(int) cells in both mice. The difference was a compensatory expansion of NK and gammadelta T cells in beta(2)m(-/-) mice, and an elimination experiment showed that these lymphocytes were critical for protection in these mice. These results suggest that malaria protection might be events of the innate immunity associated with multiple subsets with autoreactivity. CD8(+) T and NKT cells may be partially related to this protection.
authors.affiliation: Department of Immunology, Niigata University School of Medicine, Niigata, Japan.
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Taniguchi
authors.forename: Saoko
authors.initials: S
authors.lastname: Tachikawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kanda
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kawamura
authors.forename: Chikako
authors.initials: C
authors.lastname: Tomiyama-Miyaji
authors.forename: Changchun
authors.initials: C
authors.lastname: Li
authors.forename: Hisami
authors.initials: H
authors.lastname: Watanabe
authors.forename: Hiroho
authors.initials: H
authors.lastname: Sekikawa
authors.forename: Toru
authors.initials: T
authors.lastname: Abo
mesh_terms: D000818:Animals; D002455:Cell Division / Q000276:immunology; D004912:Erythrocytes / Q000469:parasitology; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D007113:Immunity, Innate; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology; D018655:Lymphocyte Count; D008288:Malaria / Q000276:immunology* / Q000517:prevention & control; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018512:Parasitemia / Q000276:immunology; D010967:Plasmodium yoelii; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D001613:beta 2-Microglobulin / Q000172:deficiency*
chemical_list: D015395:Histocompatibility Antigens Class I; D016692:Receptors, Antigen, T-Cell, gamma-delta; D001613:beta 2-Microglobulin