Vγ gene usage in peripheral blood γδ T cells

Abstract

The majority (50–90%) of γδ T cells in the peripheral blood of adult individuals expresses a T-cell receptor (TCR) which uses Vγ9 and Vδ2 as variable elements. Little is known about the distribution of other Vγ gene elements in the remaining 10–50% of γδ T cells. Here we have studied the Vγ gene expression in peripheral blood γδ T cells by 3-color flow cytometry analysis applying established monoclonal antibodies (mAb) directed against Vγ9 and Vγ4, as well as a novel mAb directed against Vγ2, Vγ3 and Vγ4. On average, 79.9% of γδ T cells expressed Vγ9, 11.9% Vγ2/Vγ3, 4.4% Vγ4, and 7.5% one of the remaining Vγ5, Vγ8, Vγ10 or Vγ11 elements. There were remarkable variations in the γδ subset composition between individual donors. The majority (69.8%) of Vγ2/Vγ3/Vγ4-bearing cells co-expressed Vδ1, while on average only 17.8% of Vγ2/Vγ3/Vγ4-bearing cells co-expressed Vδ2. This is in contrast to Vγ9-bearing γδ T cells, of which 83.1% used Vδ2 and only 12.7% Vδ1. Taken together, this data identifies Vγ2/Vγ3 as the second most frequently used set of Vγ elements in human peripheral blood γδ T cells.