Alterations in the T-Cell receptor variable gene-restricted profile of CD8+ T lymphocytes in the peripheral circulation of patients with squamous cell carcinoma of the head and neck

Purpose: Apoptosis of activated CD8(+) T cells is often seen in tumor-infiltrating lymphocytes and circulating peripheral blood mononuclear cells (PBMC) in patients with squamous cell carcinoma of the head and neck (SCCHN). We investigated whether T-cell receptor (TCR) variable beta chain (V beta)-restricted T cells were more sensitive to apoptosis than non-TCR V beta-restricted T cells. Experimental Design: Flow cytometry analysis with anti-TCR V beta antibodies was used to define expansions and contractions of V beta-restricted T cells in patients with SCCHN relative to normal donors. This staining was combined with Annexin V binding to indicate early T-cell apoptosis. Results: The TCR V beta profiles of CD+ T cells in tumor-infiltrating lymphocytes and PBMCs of patients with SCCHN were altered relative to controls, with one to five expansions and numerous contractions of TCR V beta-restricted T cells detected. These types of alterations were significantly greater in CD8(+) than CD4(+) T cells. Enhanced Annexin V binding to CD8(+) T cells was evident in PBMCs obtained from all patients, with 3 of 13 showing preferential targeting for apoptosis of TCR V beta -restricted T cells. Conclusions: TCR V beta profiles of CD8(+) T cells were altered in patients with SCCHN relative to normal controls. This may reflect increased apoptosis of expanded or contracted CD8(+) T cells, which define the TCR V beta profile of antigen-responsive T-cell populations in patients with cancer.