title: Interleukin-12-responding asialoGM1+CD8+ central memory-type T cells as precursor cells for interferon-gamma-producing killer T cells.
abstract: While investigating CD8(+) memory T cells in unimmunized C57BL/6 mice, we found that there were unique memory-type CD8(+) T cells expressing asialoGM1 (ASGM1), CD62L and CCR7 cell surface molecules, which occupied approximately 10% of CD8(+) T cells and 35% of CD44(+) memory CD8(+) T cells. Culture of freshly isolated ASGM1(+)CD8(+) T cells with interleukin (IL)-12 plus IL-2 caused the proliferation and generation of killer T cells. Moreover, ASGM1(+)CD8(+) T cells, but not ASGM1(-)CD8(+) T cells, produced high levels of interferon (IFN)-gamma in response to IL-12 plus IL-2. Although ASGM1(+)CD8(+) T cells showed no significant responses to IL-12 alone or IL-2 alone, pulse incubation of ASGM1(+)CD8(+) T cells with IL-12 at an earlier time (0-12 h), and subsequently with IL-2 at a later time (12-24 h), caused the same levels of proliferation, killer cell generation and IFN-gamma production as when they were incubated simultaneously with IL-12 plus IL-2 for 24 h. Thus, ASGM1(+)CD8(+) T cells appeared to respond to IL-12 directly to acquire IL-2 responsiveness and differentiate into IFN-gamma-producing killer T cells. Indeed, freshly isolated ASGM1(+)CD8(+) T cells, but not ASGM1(-)CD8(+) T cells, expressed higher levels of IL-12R beta2 mRNA. The fact that IL-12 administration in vivo caused the generation of ASGM1(+)CD8(+) killer T cells in an IFN-gamma-dependent manner further indicated a physiological significance of ASGM1(+)CD8(+) central memory-type T cells in IL-12-induced immunoregulation for the therapy of tumors and infectious diseases.
authors.affiliation: Division of Immunoregulation, Section of Disease Control, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Akemi
authors.initials: A
authors.lastname: Kosaka
authors.forename: Ushaku
authors.initials: U
authors.lastname: Lee
authors.forename: Daiko
authors.initials: D
authors.lastname: Wakita
authors.forename: Naoki
authors.initials: N
authors.lastname: Matsubara
authors.forename: Yuji
authors.initials: Y
authors.lastname: Togashi
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Nishimura
authors.forename: Hidemitsu
authors.initials: H
authors.lastname: Kitamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishimura
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D004338:Drug Combinations; D005434:Flow Cytometry; D005677:G(M1) Ganglioside / Q000276:immunology* / Q000378:metabolism; D007156:Immunologic Memory / Q000187:drug effects* / Q000502:physiology; D007371:Interferon-gamma / Q000378:metabolism*; D018664:Interleukin-12 / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018123:Receptors, Interleukin / Q000235:genetics / Q000378:metabolism; D053707:Receptors, Interleukin-12; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D004338:Drug Combinations; C508443:Il12rb2 protein, mouse; D007376:Interleukin-2; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D053707:Receptors, Interleukin-12; D018664:Interleukin-12; D005677:G(M1) Ganglioside; C018835:asialo GM1 ganglioside; D007371:Interferon-gamma