Gene Cloning And Distribution, Expression Of PTA1 Molecule, A Novel Member Of Immunoglobulin Superfamily

Platelet and T cell activation antigen 1 (PTA1) was initially identified by LeoA1 mAb in 1985. PTAl,67KD type I transmenbrane glycoprotein, mainly express on the surface of activation T cells and platelets related to the development of human cytotoxic T cells (CTL) as well as platelet activation and aggregation. Furthermore preliminary clinical invastigation demonstrated that PTA1 molecules was involved in autoimmune diseases and virus infection.Clearly, further understanding the functin of PTA1 requires knowledge of its primary structure. In order to carry out the studies on the structure, function and gene cloning of PTA1, the mRNA from TPA-activated Jurkat cells were used as templates to synthesize their cDNA by reverse transcription. The cDNA were ligated with λgt11 —arms and the recombinant cDNA that were pakaged in vitro were used to infect E. coli Y1090. The cDNA library of 1×10~6 pfu/ml was obtained and the recombinant rate reached to 90%. PCR technique was applied to screen positive recombinants. Four positive clones were obtained by using PTA1 mAb. Recently, the cDNA encoding PTA1 has been cloned from activated Jurkat cells by Sherrington and show it to be a novel member of the im-munoglobulin superfamity with the unusual structure of two V domains only. This result provided a fundamental base for further study on PTA1 functions and...