Germline bias dictates cross-serotype reactivity in a common dengue-virus-specific CD8+ T cell response

Nat Immunol. 2017 Nov;18(11):1228-1237. doi: 10.1038/ni.3850. Epub 2017 Sep 25.

Abstract

Adaptive immune responses protect against infection with dengue virus (DENV), yet cross-reactivity with distinct serotypes can precipitate life-threatening clinical disease. We found that clonotypes expressing the T cell antigen receptor (TCR) β-chain variable region 11 (TRBV11-2) were 'preferentially' activated and mobilized within immunodominant human-leukocyte-antigen-(HLA)-A*11:01-restricted CD8+ T cell populations specific for variants of the nonstructural protein epitope NS3133 that characterize the serotypes DENV1, DENV3 and DENV4. In contrast, the NS3133-DENV2-specific repertoire was largely devoid of such TCRs. Structural analysis of a representative TRBV11-2+ TCR demonstrated that cross-serotype reactivity was governed by unique interplay between the variable antigenic determinant and germline-encoded residues in the second β-chain complementarity-determining region (CDR2β). Extensive mutagenesis studies of three distinct TRBV11-2+ TCRs further confirmed that antigen recognition was dependent on key contacts between the serotype-defined peptide and discrete residues in the CDR2β loop. Collectively, these data reveal an innate-like mode of epitope recognition with potential implications for the outcome of sequential exposure to heterologous DENVs.

MeSH terms

  • Adaptive Immunity / genetics
  • Adaptive Immunity / immunology
  • Amino Acid Sequence
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • CD8-Positive T-Lymphocytes / virology
  • Complementarity Determining Regions / genetics
  • Complementarity Determining Regions / immunology
  • Cross Reactions / immunology*
  • Dengue / genetics
  • Dengue / immunology
  • Dengue / virology
  • Dengue Virus / classification
  • Dengue Virus / genetics
  • Dengue Virus / immunology*
  • Epitopes, T-Lymphocyte / chemistry
  • Epitopes, T-Lymphocyte / genetics
  • Epitopes, T-Lymphocyte / immunology
  • Germ-Line Mutation / immunology*
  • HLA-A Antigens / chemistry
  • HLA-A Antigens / genetics
  • HLA-A Antigens / immunology
  • Humans
  • Models, Molecular
  • Protein Structure, Tertiary
  • Receptors, Antigen, T-Cell, alpha-beta / chemistry
  • Receptors, Antigen, T-Cell, alpha-beta / genetics
  • Receptors, Antigen, T-Cell, alpha-beta / immunology*
  • Serine Endopeptidases / genetics
  • Serine Endopeptidases / immunology
  • Serotyping
  • Surface Plasmon Resonance

Substances

  • Complementarity Determining Regions
  • Epitopes, T-Lymphocyte
  • HLA-A Antigens
  • Receptors, Antigen, T-Cell, alpha-beta
  • NS3 protease, dengue virus
  • Serine Endopeptidases