title: Human gamma delta T cells: Evolution and ligand recognition.
abstract: The γδ T cell lineage in humans remains much of an enigma due to the low number of defined antigens, the non-canonical ways in which these cells respond to their environment and difficulty in tracking this population in vivo. In this review, we survey a comparative evolutionary analysis of the primate V, D and J gene segments and contrast these findings with recent progress in defining antigen recognition by different populations of γδ T cells in humans. Signatures of both purifying and diversifying selection at the Vδ and Vγ gene loci are placed into context of Vδ1+ γδ T cell recognition of CD1d presenting different lipids, and Vγ 9Vδ2 T cell modulation by pyrophosphate-based phosphoantigens through the butyrophilins BTN3A. From this comparison, it is clear that co-evolution between γδ TCRs and these ligands is likely occurring, but the diversity inherent in these recombined receptors is an important feature in ligand surveillance.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA; Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Committee on Cancer Biology, University of Chicago, Chicago, IL 60637, USA. Electronic address: ejadams@uchicago.edu.
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Adams
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Siyi
authors.initials: S
authors.lastname: Gu
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA; Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Adrienne M
authors.initials: AM
authors.lastname: Luoma
mesh_terms: D000818:Animals; D055610:Antigens, CD1d / Q000276:immunology; D000071797:Butyrophilins; D002144:Callithrix; D011756:Diphosphates / Q000276:immunology; D019143:Evolution, Molecular; D006801:Humans; D008024:Ligands; D008213:Lymphocyte Activation / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000276:immunology; D002679:Pan troglodytes; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D055610:Antigens, CD1d; C573074:BTNL9 protein, human; D000071797:Butyrophilins; C526877:CD1D protein, human; D011756:Diphosphates; D008024:Ligands; D008562:Membrane Glycoproteins; D016692:Receptors, Antigen, T-Cell, gamma-delta
keywords: B30.2; Butyrophilin; CD1d; Phosphoantigens; T cell receptor; T cells; Vdelta1; Vgamma9Vdelta2