Positive selection of Tcrb-V4+CD8+ T cells by H-2d molecules

Negative selection of Tcra-V8+CD8+ T cells by MHC class I molecules

“…This demonstration of Tcra-V-specific negative selection also raises the possibility that Tcra-V-specific positive selection might also take part in shaping the T cell repertoire, by analogy with the Tcrb-V-specific positive selection (MacDonald et al 1988b;Blackman et al 1989;Zuniga-Pflucker et al 1989;Liao et al 1989;Tomonari and Fairchild 1990;. This demonstration of Tcra-V-specific negative selection also raises the possibility that Tcra-V-specific positive selection might also take part in shaping the T cell repertoire, by analogy with the Tcrb-V-specific positive selection (MacDonald et al 1988b;Blackman et al 1989;Zuniga-Pflucker et al 1989;Liao et al 1989;Tomonari and Fairchild 1990;.…”

Tolerance in vivo and in vitro

“…Although V^4'^ T cells do not seem to be selected negatively in various strains of mice, it was suggested that V^4'^ CD8"^ T cells are positively selected in mice expressing H-2'' molecules ). Supportive evidence for the positive selection has been obtained from examination of V^4'^ CD8^ T cells and the H-2 haplotype in {(DBA/2 xC58)Fl xC58} backcross mice and in CBXC, BXC, and BXD recombinant inbred mice (Tomonari & Fairchild 1990).…”

Influence of Viral Superantigens on Vβ‐and Vα Specific Positive and Negative Selection

“…Vfi-specific positive selection T cells Ligands Tomonari 1992bTomonari & Fairchiid 1990Tomonari unpublished Tomonari & Fairchild 1990MacDonald et al 1988bBenoist & Mathis 1989;Bill & Palmer 1989;H-2'"^>H-Tomonari & Fairchiid 1992Tomonari unpublished Tomonari unpublished Tomonari unpublished Tomonari unpublished Tomonari unpublished Tomonari et al 1992a>H-2S H-Tomonari et al 1992aLiao et al 1989Blackman et al 1989Ztiniga-Pflucker et al 1989 The hierarchy in MHC class I molecules, which positively select Vjg6+CD8* and T cells, is shown in the order: from the highest to the lowest. regions in certain Vj6 elements, which are thought to interact with MHC molecules (Davis & Bjorkman 1988), have higher avidity than others for particular MHC molecules.…”

“…We have carried out extensive analyses of V^-specific positive selection with various combinations of backcross mice hoping to find evidence for the presence of non-H-2 genes encoding putative Hgands involved in positive selection (Tomonari & Fairchild 1990, Tomonari et al 1992a, Tomonari 1992b. However, our analysis did not reveal any involvement of non-H-2 (super)antigens in these V^-specific positive selection processes: the selection appears to be solely determined by MHC molecules, because the distribution of positively selected T cells is monophasic (Tomonari & Fairchild 1990, Tomonari et al 1992a, Tomonari 1992b. Furthermore, superantigens which associate with MHC class I molecules have not been identified.…”

“…The first reported example was positive selection of V^6+CD4+ T ceils (MacDonald et al 1988b). These selection processes appears to be a stage after the CD4 and CD8 litieages are determined in the thymus, because in the majority of cases either the CD4 or CD8 populations bearing certain V^ elements are selected (Benoist & Mathis 1989, Bill & Palmer 1989, Tomonari & Fairchild 1990, Tomonari et al 1992a, Tomonari 1992b. In contrast, V/l-specific negative selection by viral superantigens occurs earlier than V/i-specific positive selection.…”