title: The surprising kinetics of the T cell response to live antigenic cells.
abstract: Cooperation between CD4(+) and CD8(+) T cells is required for the proper development of primary effector and memory CD8(+) T cells following immunization with noninflammatory immunogens. In this study, we characterized murine CD4(+) and CD8(+) T cell responses to male-specific minor histocompatibility (HY) Ags following injection of live male cells into females of the same strain. Male cells are rejected 10-12 days after transfer, coinciding with the expansion and effector function of CD8(+) CTLs to two H-2D(b)-restricted epitopes. Although anti-HY CD4(+) T cell responses are readily detectable day 5 posttransfer, CD8(+) responses are undetectable until day 10. The early CD4(+) response is not dependent on direct presentation of Ag by donor male cells, but depends on presentation of the male cells by recipient APC. The CD4(+) T cell response is required for the priming of CD8(+) T cell effector responses and rejection of HY-incompatible cells. Unexpectedly, HY-specific CD4(+) T cells are also capable of efficiently lysing target cells in vivo. The delay in the CD8(+) T cell response can be largely abrogated by depleting T cells from the male inoculum, and donor male CD8(+) T cells in particular suppress host anti-HY CD8(+) responses. These data demonstrate dramatic differences in host T cell responses to noninflammatory Ags compared with responses to pathogens. We explain the delayed CD8(+) response by proposing that there is a balance between cross-presentation of Ag by helper cell-licensed dendritic cells, on the one hand, and veto suppression by live male lymphocytes on the other.
authors.affiliation: Department of Immunology and Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Tyznik
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bevan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D006182:H-Y Antigen / Q000502:physiology*; D007700:Kinetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D013094:Spermatozoa / Q000637:transplantation; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D006182:H-Y Antigen