人白细胞分化抗原CD28基因克隆及序列分析

ＣＤ２８分子是秀达于Ｔ淋巴细胞表面的大小约４４ｋＤ的双链同型二聚体多肽分子。ＣＤ２８可以通过共刺激的途径激活杀伤性Ｔ淋巴细胞，在肿瘤免疫中发挥重要作用，为了真核细胞表达ＣＤ２８分子并制备ＣＤ２８分子的单克隆抗体，以进一步研究ＣＤ２８分子在信号传递方面的功能，利用逆转录多聚酶链反应的方法，扩增了人ＣＤ２８分子的全序列基因，并将其克隆于ｐＵＣ１９质粒，进行了ＤＮＡ序列分析，为真核细胞表达ＣＤ２８分子并

STUDY ON CLONING AND SEQUENCING OF cd28

D28 is an adhesion receptor expressed as a 44kD dimer on the surface of a major subset ofhuman T cells. The CD28 recepter regulates the production of lymphokines,including inter-leukin 2(IL-2),by activation of a costimulating signal transduction pathway. Recent studieshave dernonstrated that efficient activation of T cells requires costimulation of the CD28 receptorvia the B7 molecule on antigen-presentitig cells. Inadequate costimufation of tumor-reactive Tcells may contribute to the fact that antigenic tumors are not normally rejected by the immunesystem and vveak antitumor immune responses may be amplified by upregulation of CD28 trig-gering. In order to express the CD28 gene and preperate monoclonal anti-CD28,we have prolif-erated and isolated a cDNA clone encoding CD28 by PCR method,and then we have sequencedthe cloned plasmid including CD28 gene.