Role of adhesion molecules in recruitment of Vdelta1 T cells from the peripheral blood to the tumor tissue of esophageal cancer patients.

The mechanism responsible for tissue specific localization of gammadelta T cell subsets is not well understood. In order to explain the sequestration of specific gammadelta T cell subsets in the peripheral blood and tumor tissue of patients with esophageal cancer, we examined the function and expression of adhesion molecules on these cells. A hierarchy in the expression of adhesion molecules was observed. In vitro activated gammadelta T cells showed dominant expression of LFA-1 (CD11a), VLA-alpha4 (CD49d), intermediate expression of VLA-alpha5 (CD49e) and L-selectin (CD62L), but low expression of CD44v6 and alphaEbeta7 (CD103). It was observed that the gammadelta T cells use LFA-1, L-selectin and CD44v6 to bind to squamous cell carcinoma (SCC) cells, whereas they adhere to fibroblast cells using LFA-1, VLA-alpha4 and VLA-alpha5. Vdelta1 T cell subsets from the peripheral blood gammadelta T cells utilize a larger array of adhesion molecules, namely LFA-1, VLA-alpha4, VLA-alpha5, L-selectin and alphaEbeta7, to bind to SCC cells compared to the restricted usage of LFA-1, L-selectin and CD44v6 by the Vdelta2 T cells. Flow cytometric analysis of tumor infiltrating lymphocytes from the esophageal tumors confirmed the selective accumulation of Vdelta1+ gammadelta T cells in the tumor compartment. It thus appears that adhesion molecules expressed on these lymphocytes play an important role in the recruitment and retention of Vdelta1 T cells in the tumor milieu.