PMID: 27036003 , Related PDB ids: 5HHM, 5HHN, 5HHO, 5HHP, 5HHQ

Authors:

Valkenburg SA, Josephs TM, Clemens EB, Grant EJ, Nguyen TH, Wang GC, Price DA, Miller A, Tong SY, Thomas PG, Doherty PC, Rossjohn J, Gras S, Kedzierska K

Title:

Molecular basis for universal HLA-A*0201-restricted CD8+ T-cell immunity against influenza viruses.

Journal:

Proc Natl Acad Sci U S A. 2016 Apr 19;113(16):4440-5. doi:, 10.1073/pnas.1603106113. Epub 2016 Mar 31.

Abstract:

Memory CD8(+)T lymphocytes (CTLs) specific for antigenic peptides derived from internal viral proteins confer broad protection against distinct strains of influenza A virus (IAV). However, immune efficacy can be undermined by the emergence of escape mutants. To determine how T-cell receptor (TCR) composition relates to IAV epitope variability, we used ex vivo peptide-HLA tetramer enrichment and single-cell multiplex analysis to compare TCRs targeted to the largely conserved HLA-A*0201-M158and the hypervariable HLA-B*3501-NP418antigens. The TCRalphabetas for HLA-B*3501-NP418 (+)CTLs varied among individuals and across IAV strains, indicating that a range of mutated peptides will prime different NP418-specific CTL sets. Conversely, a dominant public TRAV27/TRBV19(+)TCRalphabeta was selected in HLA-A*0201(+)donors responding to M158 This public TCR cross-recognized naturally occurring M158variants complexed with HLA-A*0201. Ternary structures showed that induced-fit molecular mimicry underpins TRAV27/TRBV19(+)TCR specificity for the WT and mutant M158peptides, suggesting the possibility of universal CTL immunity in HLA-A*0201(+)individuals. Combined with the high population frequency of HLA-A*0201, these data potentially explain the relative conservation of M158 Moreover, our results suggest that vaccination strategies aimed at generating broad protection should incorporate variant peptides to elicit cross-reactive responses against other specificities, especially those that may be relatively infrequent among IAV-primed memory CTLs.