| First Author | Guan J | Year | 2017 |
| Journal | J Immunol | Volume | 198 |
| Issue | 5 | Pages | 2017-2027 |
| PubMed ID | 28108559 | Mgi Jnum | J:252354 |
| Mgi Id | MGI:5926982 | Doi | 10.4049/jimmunol.1600764 |
| Citation | Guan J, et al. (2017) Antigen Processing in the Endoplasmic Reticulum Is Monitored by Semi-Invariant alphabeta TCRs Specific for a Conserved Peptide-Qa-1b MHC Class Ib Ligand. J Immunol 198(5):2017-2027 |
| abstractText | Ag processing in the endoplasmic reticulum (ER) by the ER aminopeptidase associated with Ag processing (ERAAP) is central to presentation of a normal peptide-MHC class I (MHC I) repertoire. Alternations in ERAAP function cause dramatic changes in the MHC I-presented peptides, which elicit potent immune responses. An unusual subset of CD8+ T cells monitor normal Ag processing by responding to a highly conserved FL9 peptide that is presented by Qa-1b, a nonclassical MHC Ib molecule (QFL) in ERAAP-deficient cells. To understand the structural basis for recognition of the conserved ligand, we analyzed the alphabeta TCRs of QFL-specific T cells. Individual cells in normal wild-type and TCRbeta-transgenic mice were assessed for QFL-specific TCR alpha- and beta-chains. The QFL-specific cells expressed a predominant semi-invariant TCR generated by DNA rearrangement of TRAV9d-3-TRAJ21 alpha-chain and TRBV5-TRBD1-TRBJ2-7 beta-chain gene segments. Furthermore, the CDR3 regions of the alpha- as well as beta-chains were required for QFL ligand recognition. Thus, the alphabeta TCRs used to recognize the peptide-Qa-1 ligand presented by ERAAP-deficient cells are semi-invariant and likely reflect a conserved mechanism for monitoring the fidelity of Ag processing in the ER. |
