title: Deficient positive selection of CD4 T cells in mice displaying altered repertoires of MHC class II-bound self-peptides.
abstract: The role of self-peptides in positive selection of CD4+ T cells has been controversial. We show that some self-peptides are presented by the MHC class II molecule I-A(b) in mice lacking Ii or H-2M but not in mice expressing a transgene-encoded peptide fused to I-A(b). In experiments using specific antibodies to block selection, these low-abundance self-peptides were implicated in the positive selection of some CD4+ T cells in H-2M-/- mice. However, all three mutant backgrounds failed to positively select two class II-restricted transgenic T cell receptors. Our findings suggest that minor components of the self-peptide repertoire can contribute to positive selection of a significant number of CD4+ T cells. In addition, the data suggest that T cell receptor repertoires selected in wild-type mice and in mice displaying limited spectra of self-peptides are distinct.
authors.affiliation: Department of Immunology, University of Washington, Seattle 98195, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Grubin
authors.forename: S
authors.initials: S
authors.lastname: Kovats
authors.forename: P
authors.initials: P
authors.lastname: deRoos
authors.forename: A Y
authors.initials: AY
authors.lastname: Rudensky
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D004848:Epithelium / Q000276:immunology / Q000378:metabolism; D005260:Female; D006183:H-2 Antigens / Q000235:genetics / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010455:Peptides / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D013950:Thymus Gland / Q000276:immunology / Q000378:metabolism; D019076:Transgenes / Q000276:immunology
chemical_list: D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II; D010455:Peptides; D016693:Receptors, Antigen, T-Cell, alpha-beta