Positive selection of the normal repertoire of TCRs results from low-avidity interactions with a set of self-peptides bound to the MHC molecules expressed by thymic epithelial cells. The contribution of the individual peptide to positive selection remains a matter of debate. Here, for the first time, we show that two covalent class II MHC-peptide complexes positively select different TCRs expressing a common transgenic TCRβ-chain and endogenous TCRα-chains. Simultaneous expression of both Ab-peptide complexes changed the diversity of positively selected TCRs, indicating an additive and possibly synergistic effect of various peptides in this process.
ASJC Scopus subject areas
- Immunology and Allergy