title: CD8beta knockout mice mount normal anti-viral CD8+ T cell responses--but why?
abstract: It has been shown previously that CD8beta in vitro increases the range and the sensitivity of antigen recognition and in vivo plays an important role in the thymic selection of CD8+ T cells. Consistent with this, we report here that CD8+ T cells from CD8beta knockout (KO) P14 TCR transgenic mice proliferate inefficiently in vitro. In contrast to these findings, we also show that CD8beta KO mice mount normal CD8 primary, secondary and memory responses to acute infection with lymphocytic choriomeningitis virus. Tetramer staining and cytotoxic experiments revealed a predominance of CD8-independent CTL in CD8beta KO mice. The TCR repertoire, especially the one of the TCRalpha chain, was different in CD8beta KO mice as compared with B6 mice. Our results indicate that in the absence of CD8beta, CD8-independent TCRs are preferentially selected, which in vivo effectively compensates for the reduced co-receptor function of CD8alphaalpha.
authors.affiliation: Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, 1066 Epalinges, Switzerland.
authors.forename: Georgi S
authors.initials: GS
authors.lastname: Angelov
authors.forename: Philippe
authors.initials: P
authors.lastname: Guillaume
authors.forename: Immanuel F
authors.initials: IF
authors.lastname: Luescher
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001117:Arenaviridae Infections / Q000276:immunology*; D016827:CD8 Antigens / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003602:Cytotoxicity, Immunologic; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D014162:Transfection
chemical_list: D000956:Antigens, Viral; D016827:CD8 Antigens; C526846:Cd8b1 protein, mouse; D007371:Interferon-gamma