Direct recognition of an intact foreign protein by an αβ T cell receptor.

ABSTRACT: αβ T cell receptors (αβTCRs) co-recognise antigens when bound to Major Histocompatibility Complex (MHC) or MHC class I-like molecules. Additionally, some αβTCRs can bind non-MHC molecules, but how much intact antigen reactivities are achieved remains unknown. Here, we identify an αβ T cell clone that directly recognises the intact foreign protein, R-phycoerythrin (PE), a multimeric (αβ)₆γ protein complex. This direct αβTCR-PE interaction occurs in an MHC-independent manner, yet triggers T cell activation and bound PE with an affinity comparable to αβTCR-peptide-MHC interactions. The crystal structure reveals how six αβTCR molecules simultaneously engage the PE hexamer, mediated by the complementarity-determining regions (CDRs) of the αβTCR. Here, the αβTCR mainly binds to two α-

SUBMITTER: Almeida CF 

PROVIDER: S-EPMC11470135 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature