Download MendeleyHow H13 histocompatibility peptides differing by a single methyl group and lacking conventional MHC binding anchor motifs determine self-nonself discrimination.
Ostrov, D.A., Roden, M.M., Shi, W., Palmieri, E., Christianson, G.J., Mendoza, L., Villaflor, G., Tilley, D., Shastri, N., Grey, H., Almo, S.C., Roopenian, D., Nathenson, S.G.(2002) J Immunol 168: 283-289
- PubMed: 11751972
- DOI: https://doi.org/10.4049/jimmunol.168.1.283
- Primary Citation of Related Structures:
1INQ, 1JUF - PubMed Abstract:
The mouse H13 minor histocompatibility (H) Ag, originally detected as a barrier to allograft transplants, is remarkable in that rejection is a consequence of an extremely subtle interchange, P4(Val/Ile), in a nonamer H2-D(b)-bound peptide. Moreover, H13 peptides lack the canonical P5(Asn) central anchor residue normally considered important for forming a peptide/MHC complex. To understand how these noncanonical peptide pMHC complexes form physiologically active TCR ligands, crystal structures of allelic H13 pD(b) complexes and a P5(Asn) anchored pD(b) analog were solved to high resolution. The structures show that the basis of TCRs to distinguish self from nonself H13 peptides is their ability to distinguish a single solvent-exposed methyl group. In addition, the structures demonstrate that there is no need for H13 peptides to derive any stabilization from interactions within the central C pocket to generate fully functional pMHC complexes. These results provide a structural explanation for a classical non-MHC-encoded H Ag, and they call into question the requirement for contact between anchor residues and the major MHC binding pockets in vaccine design.
Organizational Affiliation:
Department of Biochemistry, Albert Einstein College of Medicine, 1600 Morris Boulevard, Bronx, NY 10461, USA.
