Colorectal cancer patients have oligoclonal proliferation of T cells in blood / 北京大学学报(医学版)

ABSTRACT

Objective: To study the clonal characteristics of peripheral T cells and anti tumor immunology in the patients with colorectal cancer by analyzing T cell receptor beta (TCR?) gene repertoire and complementarity determining regions 3 (CDR3) amino acid sequence of the peripheral blood cells (PBL). Methods:The 24 TCR?V genes from PBL in pre operation and post operation and colorectal cancer tissues, were amplified by the method of combined reverse transcriptase polymerase chain reaction (RT-PCR) with denaturation polyacrylamide sequencing gel eletrophoresis, which is called TCR? gene repertoire. In order to analyze the clonality of the over expressing bands and the CDR3 sequence, the PCR production was sequenced directly. Results: TCR? gene repertoire of PBL in the tumor bearing patients was clonally expressed, which indicated that there were monoclonal or oligoclonal expansion of T lymphocytes. Some of the clonal T cells in PBL had the same CDR3 amino acid sequence motifs with the clonal T cells in the tumor infiltrating lymphocyte(TIL). The patients with clonal expansion of T cells in PBL had lymph node metastases, but there was no recurrence within 10 months after operation. Conclusion: There is oligoclonal proliferation of T cells in the blood of tumor bearing patients. It is possible that the clonal T lymphocytes are the tumor associated antigen specific anti tumor T lymphocytes.