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目的：获得人血小板／Ｔ细胞活化抗原１（ｐｌａｔｅｌｅｔａｎｄＴｃｅｌａｃｔｉｖａｔｉｏｎａｎｔｉｇｅｎ１，ＰＴＡ１）胞膜外区与人ＩｇＧ１Ｆｃ段融合蛋白，为ＰＴＡ１配体的鉴定及其功能的研究提供有力的工具。方法：针对人ＰＴＡ１ｃＤＮＡ序列设计３段引物，通过反转录、半套式ＰＣＲ方法从活化Ｊｕｒｋａｔ细胞中扩增出ＰＴＡ１胞膜外区基因片段，并将其克隆入融合蛋白表达载体ｐＩＧ中，通过酶切、ＰＣＲ及序列测定鉴定重组表达载体。重组载体通过ＤＥＡＥｄｅｘｔｒａｎ法转染ＣＯＳ７细胞，经夹心ＥＬＩＳＡ及亲和层析、ＳＤＳＰＡＧＥ鉴定融合蛋白的表达及免疫学活性。结果：经序列测定后证实重组表达载体含有正确的ＰＴＡ１胞膜外区序列及剪接供体序列，转染ＣＯＳ７细胞后，通过亲和层析纯化证实融合蛋白的Ｍｒ为８３０００，并能被抗ＰＴＡ１胞膜外区单抗及抗人ＩｇＧＦｃ的单抗同时识别。结论：ｐＰＴＡ１／Ｉｇ融合表达载体的构建及表达成功，为ＰＴＡ１的功能及配体（ＰＴＡ１Ｌ）的研究打下了良好的基础。
OBJECTIVE: To obtain fusion protein of extracellular domain of human platelet and T cell activating antigen 1 (PTA1) and human IgG1 Fc, and to provide a powerful tool for the identification of PTA1 ligand and its function. Methods: According to the sequence of human PTA1 cDNA, three primers were designed and the extracellular region of PTA1 gene was amplified from activated Jurkat cells by reverse transcription and semi-nested PCR and cloned into the pIG1 fusion protein expression vector Digestion, PCR and sequencing to identify the recombinant expression vector. Recombinant vector by DEAE dextran method transfected COS 7 cells by sandwich ELISA and affinity chromatography, SDS PAGE identified fusion protein expression and immunological activity. Results: After sequencing, the recombinant expression vector was confirmed to contain the correct PTA1 extracellular domain sequence and the splice donor sequence. After transfection of COS7 cells, the fusion protein Mr 83000 was confirmed by affinity chromatography and was able to be Monoclonal antibodies against PTA1 extracellular membrane and anti-human IgGFc were identified simultaneously. Conclusion: The construction of pPTA1 / Ig fusion expression vector and its successful expression lay a good foundation for the study of PTA1 function and ligand (PTA1L).