中文摘要：

目的克隆旋毛虫肌幼虫肘，21000抗原蛋白基因（Ts21），预测其T细胞和B细胞表位。方法旋毛虫（河南地理株）感染小鼠后收集肌幼虫，提取肌幼虫总RNA，应用RT-PCR技术获取目的基因Ts21，构建重组质粒pUC18—Ts21并测序，应用生物信息分析软件预测其T细胞和B细胞表位。结果成功构建克隆载体pUC18-Ts21。旋毛虫M21000抗原的T细胞表位位于第9—23、135—150位氨基酸位点；B细胞表位位于第31-35、53—56、98—104、124—130、133—157、160-172位氨基酸位点。结论成功克隆了旋毛虫河南地理株肌幼虫肘，21000抗原的编码基因，T细胞和B细胞表位预测结果表明该抗原蛋白具有较好的抗原性，可作为旋毛虫病免疫诊断和预防的候选抗原。

英文摘要：

Objective To clone the gene encoding M,21 000 antigen of Trichinella spiralis （Henan isolate） muscle larvae, and to predict the T cell and B cell epitopes of this antigen. Methods T. spiralis muscle larvae were collected after the mice were infected with T. spiralis, and then the total RNA of the muscle larvae were obtained. The target gene（Ts21）was obtained by using RT-PCR technique, and then the PCR products were cloned into the pUC18 vector to construct recombinant plasmid pUC18-Ts21. The DNA sequences of Ts21 gene were determined. The T and B cell epitopes of this antigen were predicted by bio-software. Results The gene encoding M,21 000 antigen of T. spiralis larvae was doned. The T cell epitope of the M,21 000 antigen of T. spiralis may be located at the aa9- 23 and 135 - 150, while the B cell epitopes may be at the aa31- 35, 53-56, 98-104, 124-130,133-157, and 160- 172. Conclusion The gene encoding M,21 000 antigen of T. spiralis （Henan isolate） muscle larvae is obtained, and the T cell and B cell epitopes are predicted. The results suggest that the M,21 000 protein has good antigenicity and might be used as the candidate antigen for the immunodiagnosis and immunoprophylaxis of trichinellosis.