Heat shock protein induced TCR γδ gene rearrangements in patients with oral cancer

We analyzed the T cell receptor (TCR) γδ gene repertoire in peripheral blood and tumor compartment of oral cancer (OC) patients before and after stimulation with heat shock proteins (hsp), which are known ligands for γδ T cells. Clonal TCR γ and δ gene rearrangements in lymphocytes from tumor compartment and peripheral blood were studied using TCR Vγ and Vδ gene primers in PCR followed by heteroduplex analysis. Vγ gene segments derived from VγI or VγII gene families were most dominantly expressed in peripheral blood lymphocytes (PBL) as compared to tumor infiltrating lymphocytes (TIL) of OC patients. Of the rearranged TCR δ alleles Vδ1-Jδ1 and Vδ2-Jδ1 gene rearrangements were the most predominant in PBL and TIL of OC patients respectively. Stimulation of γδ T cells with hsp 60/70 demonstrated a selective clonal expansion of Vγ9-Vδ2 (VγII family) subset indicating that, this expanded population of cells could be responsible for eliciting an immune response against oral tumor cells.