Document 0160
 DOCN  M95B0160
 TI    Strong agonist ligands for the T cell receptor do not mediate positive
       selection of functional CD8+ T cells.
 DT    9511
 AU    Hogquist KA; Jameson SC; Bevan MJ; Howard Hughes Medical Institute,
       Department of Immunology,; University of Washington, Seattle 98195, USA.
 SO    Immunity. 1995 Jul;3(1):79-86. Unique Identifier : AIDSLINE MED/95346512
 AB    Positive selection of functional CD8+ T cells expressing an MHC class
       I-restricted T cell receptor can be induced in fetal thymus organ
       culture by class I-binding peptides related to the antigenic peptide
       ligand. Peptides that act as antagonist or weak agonist/antagonist
       ligands for mature T cells work efficiently in this regard. In the
       present study, we have investigated whether low concentrations of the
       original agonist peptide, or variants that still have a strong agonist
       activity can also mediate positive selection. The antigenic peptide did
       not induce positive selection at any concentration tested. A strong
       agonist variant was capable of stimulating the differentiation of TCRhi
       CD8+ cells, giving the appearance of phenotypic positive selection.
       However, these cells lacked biological function, since they could not
       proliferate in response to antigen. The most efficient positive
       selection resulted with ligands that did not activate mature T cells or
       stimulate negative selection.
 DE    Animal  CD8-Positive T-Lymphocytes/*IMMUNOLOGY  Ligands  Mice  Mice,
       Inbred C57BL  Organ Culture  Receptors, Antigen,
       T-Cell/AGONISTS/*IMMUNOLOGY  Support, Non-U.S. Gov't  Support, U.S.
       Gov't, P.H.S.  T-Lymphocyte Subsets/IMMUNOLOGY  Thymus
       Gland/EMBRYOLOGY/*IMMUNOLOGY  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).