These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Constitutive presentation of dominant epitopes from endogenous naturally processed self-beta 2-microglobulin to class II-restricted T cells leads to self-tolerance.
    Author: Guéry JC, Sette A, Appella E, Adorini L.
    Journal: J Immunol; 1995 Jan 15; 154(2):545-54. PubMed ID: 7814867.
    Abstract:
    The mouse beta 2-microglobulin (m beta 2-m) peptide corresponding to residues 25-40 binds to the MHC class II molecules I-Ad and I-Ed and is immunogenic in BALB/c beta 2-m-deficient but not in normal BALB/c mice. The self-m beta 2-m peptide 25-40 is presented by both I-Ad and I-Ed class II molecules as demonstrated by the activation of T cell hybridomas specific for this sequence obtained from beta 2-m knock-out mice. By analyzing the effect of N- and C-terminal truncations of m beta 2-m25-40 on binding to class II molecules and on activation of T cell hybridomas, the minimum epitopes recognized by I-Ad and I-Ed-restricted T cells are included within amino acid residues 26-39 and 24-36, respectively. Both sets of T hybridomas are also activated by the corresponding naturally processed self-epitope presented by APC from BALB/c mice and from other H-2d strains, irrespective of their Mls phenotype. Therefore, the sequence 25-40 contains dominant naturally processed self-epitopes of the mouse beta 2-m. Processing of endogenous m beta 2-m is sensitive to protease inhibitors and lysosomotropic amines, and is not caused by reuptake of shed or released protein. These results indicate that self-beta 2-m-peptide-MHC class II complexes derive from constitutive processing of the endogenous intracellular pool of m beta 2-m in an acidic endosomal compartment. Antigenic complexes between m beta 2-m peptides and I-Ad or I-Ed class II molecules are constitutively expressed by APC of different tissues, including the thymus, and they are able to induce T cell tolerance, as shown by the lack of T cell response to m beta 2-m25-40 in BALB/c mice.
    [Abstract] [Full Text] [Related] [New Search]