Abstract
Host immune function plays a certain role against the development of renal cell carcinomas (RCCs), but the mechanism is not entirely understood. Human gamma/delta (γ/δ) T cells defend the body against infection. In this study, we clarify the role of γ/δ T cells in the surveillance system against RCCs by analyzing the γ/δ T cells in peripheral blood mononucleocytes (PBMs) and tumor infiltrating lymphocytes (TILs) from 41 patients with RCCs. The results showed that the number of γ/δ T cells expressing Vγ2 and Vδ2 in variable elements of TCR was elevated in the PBMs in 10 patients, but not in any of 32 healthy individuals. The proportion of patients with an elevated number of γ/δ T cells (>10%) increased with cancer stage. The level of the γ/δ T cells decreased after surgery. The γ/δ T cells in the TILs were more activated than those in the PBMs. Evaluation of the junctional diversity of TCR Vγ2 and Vδ2 chains showed that the increased peripheral blood γ/δ T cells were oligoclonal rather than polyclonal. Taken together, our findings suggest that γ/δ T cells recognize certain RCC-related antigens and play a role in the surveillance system against RCCs.
Keywords: Key words Renal cell carcinoma, T cell, Immunotherapy, Flow cytometry, Vγ2 and Vδ2 junction sequences
Footnotes
Received: 30 November 2000 / Accepted: 2 January 2001