Dimorphism in the TCRγ-chain repertoire defines 2 types of human immunity to Epstein-Barr virus.

Humans form 2 groups based on their innate immunity to Epstein-Barr virus (EBV). Group 1 makes a strong natural killer (NK)-cell and γδ T-cell response, whereas group 2 makes a strong NK-cell response, but a weak γδ T-cell response. To investigate the underlying basis for this difference in γδ T-cell immunity to EBV, we used next-generation sequencing to compare the γδ T-cell receptor (TCR) repertoires of groups 1 and 2. In the absence of EBV, group 1 TCRγ chains are enriched for complementarity determining region 3 (CDR3s) containing JγP, whereas group 2 TCRγ chains are enriched for CDR3s containing Jγ2. In group 1 donors, EBV activates many γδ T cells expressing Vγ9JγP, inducing proliferation that produces a large population of activated effector cells. The TCRs using Vγ9JγP are closely related to the TCRs of γδ T cells that respond to phosphoantigens. In group 2 donors, EBV activates a small subpopulation of γδ T cells, most expressing Vγ9JγP. In conclusion, we find that differences in the TCRγ-chain repertoire underlie the differential response of group 1 and group 2 to EBV.