LT70-DPC结核亚单位疫苗安全性的初步评价

Safety of tuberculosis subunit vaccine LT70-DPC

目的初步评价以阳离子脂质体二甲基三十六烷基铵(dimo-thylidioctyl ammonium bro-mide,DDA)、聚肌胞苷酸(Poly I∶C)及胆固醇复合佐剂(简称为DPC)为佐剂的结核融合蛋白ESAT6-Ag85B-MPT64(190-198)-Mtb8.4-Rv2626c(LT70)亚单位疫苗的安全性。方法急性毒性试验:分别将低剂量与高剂量(分别相当于人用剂量的10 000和40 000倍)的LT70-DPC结核亚单位疫苗经皮下、腹腔两种途径免疫小鼠,观察小鼠毒性反应、死亡情况及体重变化等,同时推算小鼠对LT70-DPC亚单位疫苗的最大耐受剂量(maximum tolerated dose,MTD);异常毒性试验:将小鼠和豚鼠分别经腹腔注射LT70-DPC结核亚单位疫苗,观察动物异常反应、死亡情况及体重变化等;全身过敏试验:豚鼠经LT70-DPC结核亚单位疫苗免疫后,经相应疫苗静脉攻击,观察豚鼠过敏反应。结果急性毒性试验:皮下及腹腔注射后14 d内均未见小鼠的异常反应和死亡,体重均增加,小鼠对该疫苗的MTD为:LT70蛋白>6 600μg/kg,DDA>166 600μg/kg,Poly I∶C>33 200μg/kg,胆固醇>50 600μg/kg;异常毒性试验:注射后7 d内,小鼠及豚鼠全部健存,均未出现异常症状,体重增加;全身过敏试验:攻击后1 h内,豚鼠均未出现过敏反应。结论 LT70-DPC结核亚单位疫苗具有良好的安全性。

Objective To preliminarily evaluate the safety of tuberculosis fusion protein based subunit vaccine ESAT6-Ag85B-MPT64（190-198）-Mtb8. 4-Rv2626c（LT70）with the complex adjuvant DPC consisting of cationic liposomes dimothylidioctyl ammonium bromide（DDA）and poly I ∶ C and cholesterol. Methods Acute toxicity test was carried out as follows： mice were immunized with LT70-DPC tuberculosis subunit vaccine at low and high dosages（equivalent to 10 000 and 40 000 times of dosage for humans respectively） by subcutaneous and intraperitoneal routes separately, and observed for toxicity, death and bodyweight, based on which the maximum tolerated dose（MTD） of the vaccine was calculated.Abnormal toxicity test was carried out as follows： mice and guinea pigs were immunized with LT70-DPC tuberculosis subunit vaccine by intraperitoneal route and observed for abnormal reaction, death and bodyweight. However, in systematic allergy test, guinea pigs were immunized with LT70-DPC tuberculosis subunit vaccine then challenged with the vaccine by intravenous route, and observed for allergic reaction. Results In acute toxicity test, no abnormal reactions or deaths were observed in mice within 14 d after immunization, while all the bodyweights increased. The MTD of mice to LT70 protein,DDA, Poly I ∶ C and cholesterol were more than 6 600, more than 166 600, more than 33 200 and more than 50 600 μg/kg respectively. In abnormal toxicity test, all the mice and guinea pigs survived healthy within 7 d after immunization with bodyweight gained while no abnormal symptoms. However, in systemic allergic test, no allergic reactions were observed in guinea pigs within 1 h after challenge. Conclusion LT70-DPC tuberculosis subunit vaccine showed high safety.