重组蓖麻毒素A链与天然蓖麻毒素毒性与免疫效果比较∗

摘要

为比较分析重组蓖麻毒素A链（ r⁃RTA）、重组突变蓖麻毒素A链（ m⁃RTA）和天然蓖麻毒素（ n⁃RT）毒性及免疫效果。在鼠巨噬细胞（ RAW264�7）试验中，n⁃RT毒力约是m⁃RTA与r⁃RTA的2700倍。腹腔注射免疫无佐剂的r⁃RTA、m⁃RTA和n⁃RT，免疫过程中小鼠体重均有所减轻，相较于r⁃RTA组和n⁃RT组，m⁃RTA组小鼠体重变化最小。间接酶联免疫吸附试验（ ELISA）结果显示：4次免疫以后血清抗体效价均达到10－4以上，以6 mg／kg m⁃RTA免疫小鼠可对20×LD50剂量蓖麻毒素提供完全保护。该结果表明r⁃RTA、m⁃RTA和n⁃RT对小鼠均有一定毒性，m⁃RTA对小鼠刺激小，免疫鼠可获得较好的免疫保护。%The purpose of this research is to compare toxicity and immune effect of recombinant ricin A chain ( r⁃RTA) , recombinant mutant ricin A chain ( m⁃RTA) and natural ricin ( n⁃RT) . In cell test, toxicity of m⁃RTA and r⁃RTA is 2 700 times lower than n⁃RT. After Intraperitoneal injection immunization without adjuvant r⁃RTA, m⁃RTA and n⁃RT, all mice lost weight during the immune prograss, and compared to the group immunized with r⁃RTA and n⁃RT, mice in the group immu⁃nized with m⁃RTA had the smallest weight change. After four times of immunization,serum antibody titers of mice could reach above 10-4 , immunization of mice with 6 mg/kg m⁃RTA could provide full protection for 20 × LD50 dose of ricin infected. The results show that r⁃RTA, m⁃RTA and n⁃RT are all toxic to mice to some extent, and mutant m⁃RTA irritation can provide better protection to mice,which will provide vital data and theoretical supports for the development of RTA⁃based vaccine.