Abstract: Cytotoxic T lymphocytes (CTLs) are critical effectors which play important roles both in anti-tumor and antivirus immune responses. Through T-cell receptors(TCRs), CTLs can specifically recognize MHC-Ⅰ-peptides complexes presented on the surface of target cells, and then release biological substances such as perforin and granzymes into the target cells and dissolve them. Since the significant potential value of CTLs, more and more people are focusing on its basic and applied studies. Most researches are about the transformation of the TCR gene. With the development of molecular biology, cloning and transduction of TCR gene have been more mature. Researchers are finding ways to ensure that TCR gene expresses efficiently and assemble correctly.

Key words: Cytotoxic T lymphocytes, Genes, T-cell receptor, Immunotherapy