Abstract: Objective To analyze the reasons for antigen diversity of Anaplasma phagocytophilum grown in different cells. Methods The P44 transcripts were analyzed using nested RT-PCR, and the P44 proteins were produced as recombinant protein in vitro by insect cell-free protein synthesis system. Results We detected and characterized P44 transcript variants of A. phagocytophilum from THP-1 and HL60 cells. And our study demonstrated the presence of specific antibodies against the 3 type of rP44 proteins that prevailed in infected THP-1 and HL60 cells, probably being suitable as protein antigens for sero-diagnosis of human granulocytic anaplasmosis. Conclusion We demonstrated antigenic diversity of a variety of A. phagocytophilum grown in different cells.

Key words: Anaplasma phagocytophilum, P44 outer membrane protein, Anaplasmosis

摘要： 目的 调查嗜吞噬细胞无形体在不同组织细胞间产生抗原差异的原因。方法 采用RT PCR法对嗜吞噬细胞无形体在不同组织细胞中的抗原蛋白表达差异进行分析，并利用真核无细胞蛋白表达系统合成重组蛋白，利用蛋白质印迹法进行测试。结果 组织培养细胞不同，嗜吞噬细胞无形体菌体表面可产生不同的P44外膜蛋白。通过检测发现，3种rP44蛋白易与患者血清中抗体结合，可作为人粒细胞无形体病的诊断用抗原。结论 不同组织细胞间存在抗原性差异的不同嗜吞噬细胞无形体。

关键词: 嗜吞噬细胞无形体, P44外膜蛋白, 无形体病