氯仿-甲醇提取贝氏柯克斯体组分Q热疫苗的免疫保护性评价

Evaluation of immunoprotection on Q-fever vaccine of Coxiella burnetii extracted with chloroform-methanol

目的动物实验评价采用国内分离株研制的氯仿-甲醇提取贝氏柯克斯体组分Q热疫苗(CMRV)的免疫保护性。方法将三批小量制备的CMRV和灭活贝氏柯克斯体Q热疫苗(WCV)分别用1μg、10μg、100μg三个剂量皮下注射免疫BALB/c小鼠,4周后用初次免疫的一半剂量腹腔注射加强免疫1次,2周后用107的贝氏柯克斯体强毒株腹腔注射感染免疫小鼠,感染第7d活杀小鼠、摘取小鼠脾脏,用荧光定量PCR检测小鼠脾脏组织的贝氏柯克斯体。结果所有Q热疫苗免疫组的小鼠脾脏荷菌量均显著少于非免疫组,100μg免疫组的荷菌量显著低于10μg免疫组,10μg疫苗组显著低于1μg免疫组。每批CMRV免疫组与相同剂量WCV免疫组之间的贝氏柯克斯体含量无显著差异。结论国内分离株研制的氯仿-甲醇提取贝氏柯克斯体组分Q热疫苗具有与灭活Q热疫苗一样良好的抗贝氏柯克斯体感染的免疫保护性。

The immunoprotective value the Q-fever vaccine prepared from the Xinqiao strain of Coxiella burnetii isolated in China and extracted with chloroform methanol （CMRV） was evaluated in the present study, in which BALB/c mice were inoculated subcutaneously with 3 batches of CMRV and the inactivated Q-fever vaccine （WCV） respectively, and mice were re-inoculated intra-peritoneally with the homologous vaccine 4 weeks after the primary immunization. Then, the inoculated mice were challenged with 10^7 of the virulent C. burnetii intraperitoneally 2 weeks after the booster immunization. One week after challenge, mice were sacrificed and their spleens were collected and the burdens of C. burnetii in spleens were detected by quan- titative polymerase chain reaction. It was found that the burden of C. burnetii in spleens of mice immunized with CMRV or WCV were significantly lower than that of un immunized mice and no significant difference in burdens of C. burnetii was found between mice immunized with CMRV and MCV. In addition, the burden of C. burnetii in the spleens of mice immunized with 100μg of vaccine was significantly lower than that of mice immunized with 10μg of vaccine which was markedly lower than that of mice immunized with 1μg of vaccine. Collectively, it appears that CMRV prepared with the Chinese isolates of C. burnetii is efficacious to protect mice from infection with C. burnetii.