An endogenous peptide positively selects and augments the activation and survival of peripheral CD4+ T cells.
Although CD4(+) and CD8(+) T cells differ in the strength of their positively selecting signal, endogenous positively selecting ligands have been identified only for major histocompatibility complex (MHC) class I-restricted T cell antigen receptors (TCRs). Here we screened for ligands able to positively select MHC class II-restricted TCRs using thymocytes from four I-E(k)-restricted TCR-transgenic mice and a large panel of self peptides. One peptide, gp250, induced positive selection of AND CD4(+) T cells, had no homology with the AND TCR agonist ligand and was recognized with a high degree of specificity. The gp250 peptide acted as a coagonist to initiate the activation and enhance the survival of peripheral AND CD4(+) T cells. Thus, positively selecting ligands are critical in thymocyte development and in the activation and maintenance of peripheral T cells.
Lo
Wan-Lin
WL
Department of Immunology and Pathology, Washington University School of Medicine, St. Louis, Missouri, USA.
Felix
Nathan J
NJ
Walters
James J
JJ
Rohrs
Henry
H
Gross
Michael L
ML
Allen
Paul M
PM
D019943:Amino Acid Substitution; D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002460:Cell Line; D049109:Cell Proliferation; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D037181:Lectins, C-Type; D008024:Ligands; D008213:Lymphocyte Activation; D051379:Mice; D008822:Mice, Transgenic; D010455:Peptides / Q000276:immunology*; D011485:Protein Binding; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D000949:Histocompatibility Antigens Class II; D037181:Lectins, C-Type; D008024:Ligands; D010455:Peptides; D011948:Receptors, Antigen, T-Cell; D000099192:CD69 Antigens