An endogenous positively selecting peptide enhances mature T cell responses and becomes an autoantigen in the absence of microRNA miR-181a.

Journal Article (Journal Article)

Thymic positive selection is based on the interactions of T cell antigen receptors (TCRs) with self peptide-major histocompatibility complex (MHC) ligands, but the identity of selecting peptides for MHC class II-restricted TCRs and the functional consequences of this peptide specificity are not clear. Here we identify several endogenous self peptides that positively selected the MHC class II-restricted 5C.C7 TCR. The most potent of these also enhanced mature T cell activation, which supports the hypothesis that one function of positive selection is to produce T cells that can use particular self peptide-MHC complexes for activation and/or homeostasis. We also show that inhibiting the microRNA miR-181a resulted in maturation of T cells that overtly reacted toward these erstwhile positively selecting peptides. Therefore, miR-181a helps to guarantee the clonal deletion of particular moderate-affinity clones by modulating the TCR signaling threshold of thymocytes.

Full Text

Duke Authors

Cited Authors

  • Ebert, PJR; Jiang, S; Xie, J; Li, Q-J; Davis, MM

Published Date

  • November 2009

Published In

Volume / Issue

  • 10 / 11

Start / End Page

  • 1162 - 1169

PubMed ID

  • 19801983

Pubmed Central ID

  • PMC3762483

Electronic International Standard Serial Number (EISSN)

  • 1529-2916

Digital Object Identifier (DOI)

  • 10.1038/ni.1797


  • eng

Conference Location

  • United States