Structural interplay between germline interactions and adaptive recognition determines the bandwidth of TCR-peptide-MHC cross-reactivity.Adams, J.J., Narayanan, S., Birnbaum, M.E., Sidhu, S.S., Blevins, S.J., Gee, M.H., Sibener, L.V., Baker, B.M., Kranz, D.M., Garcia, K.C.
(2016) Nat. Immunol. 17: 87-94
- PubMed: 26523866
- DOI: 10.1038/ni.3310
- Primary Citation of Related Structures:
- PubMed Abstract:
The T cell antigen receptor (TCR)-peptide-major histocompatibility complex (MHC) interface is composed of conserved and diverse regions, yet the relative contribution of each in shaping recognition by T cells remains unclear. Here we isolated cross-r ...
The T cell antigen receptor (TCR)-peptide-major histocompatibility complex (MHC) interface is composed of conserved and diverse regions, yet the relative contribution of each in shaping recognition by T cells remains unclear. Here we isolated cross-reactive peptides with limited homology, which allowed us to compare the structural properties of nine peptides for a single TCR-MHC pair. The TCR's cross-reactivity was rooted in highly similar recognition of an apical 'hot-spot' position in the peptide with tolerance of sequence variation at ancillary positions. Furthermore, we found a striking structural convergence onto a germline-mediated interaction between the TCR CDR1α region and the MHC α2 helix in twelve TCR-peptide-MHC complexes. Our studies suggest that TCR-MHC germline-mediated constraints, together with a focus on a small peptide hot spot, might place limits on peptide antigen cross-reactivity.
Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.,Howard Hughes Medical Institute, and Departments of Molecular and Cellular Physiology, and Structural Biology, Program in Immunology, Stanford University School of Medicine, Stanford, California, USA.,Department of Chemistry &Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana, USA.,Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Terrence Donnelly Centre for Cellular &Biomolecular Research, Toronto, Ontario, Canada.