tetano
Editor, Senior Moderator
J Biol Chem. 2017 Sep 20. pii: jbc.M117.810382. doi: 10.1074/jbc.M117.810382. [Epub ahead of print]
[h=1]Structural basis for clonal diversity of the human T cell response to a dominant influenza virus epitope.[/h] Yang X[SUP]1[/SUP], Chen G[SUP]2[/SUP], Weng NP[SUP]2[/SUP], Mariuzza RA[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Influenza A virus (IAV) causes an acute infection in humans that is normally eliminated by CD8+ cytotoxic T lymphocytes. Individuals expressing the major histocompatibility complex (MHC) class I molecule HLA-A2 produce cytotoxic T lymphocytes bearing T cell receptors (TCRs) that recognize the immunodominant IAV epitope GILGFVFTL (GIL). Most GIL-specific TCRs utilize α/β pairs encoded by the TRAV27/TRBV19 gene combination to recognize this relatively featureless peptide epitope (canonical TCRs). However, ~40% of GIL-specific TCRs express a wide variety of other TRAV/TRBV combinations (non-canonical TCRs). To investigate the structural underpinnings of this remarkable diversity, we determined the crystal structure of a non-canonical GIL-specific TCR (F50) expressing the TRAV13-1/TRBV27 gene combination bound to GIL-HLA-A2 to 1.7 ? resolution. Comparison of the F50-GIL-HLA-A2 complex with the previously publishedcomplex formed by a canonical TCR (JM22) revealed that F50 and JM22 engage GIL-HLA-A2 in markedly different orientations. These orientations are distinguished by crossing angles of TCR to peptide-MHC of 29o for F50 versus 69o for JM22, and by a focus by F50 on the C-terminus rather than the center of the MHC α1 helix for JM22. In addition, F50, unlike JM22, uses a tryptophan instead of an arginine to fill a critical notch between GIL and the HLA-A2 α 2 helix. The F50-GIL-HLA-A2 complex shows that there are multiple structurally distinct solutions to recognizing an identical peptide-MHC ligand with sufficient affinity to elicit a broad anti-IAV response that protects against viral escape and T cell clonal loss.
Copyright ? 2017, The American Society for Biochemistry and Molecular Biology.
[h=4]KEYWORDS:[/h] T cell receptor; crystal structure; epitope; influenza virus; major histocompatibility complex (MHC); protein complex; surface plasmon resonance (SPR)
PMID: 28931605 DOI: 10.1074/jbc.M117.810382
[h=1]Structural basis for clonal diversity of the human T cell response to a dominant influenza virus epitope.[/h] Yang X[SUP]1[/SUP], Chen G[SUP]2[/SUP], Weng NP[SUP]2[/SUP], Mariuzza RA[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Influenza A virus (IAV) causes an acute infection in humans that is normally eliminated by CD8+ cytotoxic T lymphocytes. Individuals expressing the major histocompatibility complex (MHC) class I molecule HLA-A2 produce cytotoxic T lymphocytes bearing T cell receptors (TCRs) that recognize the immunodominant IAV epitope GILGFVFTL (GIL). Most GIL-specific TCRs utilize α/β pairs encoded by the TRAV27/TRBV19 gene combination to recognize this relatively featureless peptide epitope (canonical TCRs). However, ~40% of GIL-specific TCRs express a wide variety of other TRAV/TRBV combinations (non-canonical TCRs). To investigate the structural underpinnings of this remarkable diversity, we determined the crystal structure of a non-canonical GIL-specific TCR (F50) expressing the TRAV13-1/TRBV27 gene combination bound to GIL-HLA-A2 to 1.7 ? resolution. Comparison of the F50-GIL-HLA-A2 complex with the previously publishedcomplex formed by a canonical TCR (JM22) revealed that F50 and JM22 engage GIL-HLA-A2 in markedly different orientations. These orientations are distinguished by crossing angles of TCR to peptide-MHC of 29o for F50 versus 69o for JM22, and by a focus by F50 on the C-terminus rather than the center of the MHC α1 helix for JM22. In addition, F50, unlike JM22, uses a tryptophan instead of an arginine to fill a critical notch between GIL and the HLA-A2 α 2 helix. The F50-GIL-HLA-A2 complex shows that there are multiple structurally distinct solutions to recognizing an identical peptide-MHC ligand with sufficient affinity to elicit a broad anti-IAV response that protects against viral escape and T cell clonal loss.
Copyright ? 2017, The American Society for Biochemistry and Molecular Biology.
[h=4]KEYWORDS:[/h] T cell receptor; crystal structure; epitope; influenza virus; major histocompatibility complex (MHC); protein complex; surface plasmon resonance (SPR)
PMID: 28931605 DOI: 10.1074/jbc.M117.810382