重组百日咳杆菌黏附素蛋白免疫小鼠可完全抵抗支气管败血波氏杆菌的致死性感染

Protecting mice from fatal Bordetella bronchiseptica infection by immunization with recombinant pertactin antigens

【目的】通过建立的小鼠呼吸道感染模型评价重组百日咳杆菌黏附素蛋白(GST-PRN)对小鼠的免疫保护效力。【方法和结果】在主动免疫保护试验中,GST-PRN免疫组小鼠能产生较高的PRN抗体水平,在使用3×LD50的支气管败血波氏杆菌HH0809株进行呼吸道气雾攻毒后,其保护率为100%(20/20),但载体蛋白GST和PBS对照组小鼠的存活率仅为15%(3/20)和20%(4/20)。在被动免疫保护试验中,腹腔免疫GST-PRN兔抗血清能100%(10/10)保护小鼠抵抗10×LD50的HH0809株的腹腔攻击,但GST兔抗血清和PBS免疫组小鼠的存活率均为0(0/10和0/9)。【结论】研究结表明重组PRN蛋白具有良好的免疫学活性,可作为亚单位疫苗或疫苗添加成分。

[Objective] We evaluated the efficacy of the recombinant pertactin （PRN）-specific active or＇passive immunization against Bordetella bronchiseptica （Bb） in an aerosol challenge model established by using BALB/c mice. [Methods and results] Mice, immunized subcutaneously with two doses of purified glutathione S-transferase （GST）-PRN protein mixed with an equal volume of Freund＇s adjuvant, produced robust PRN-specific IgG antibody activity. All 20 mice vaccinated with GST-PRN protein survived aerosol challenge with three times the 50% lethal dose （LD50） of virulent Bb HH0809 compared with 3 of 20 GST protein-treated controls and 4 of 20 PBS-treated controls that survived. Furthermore, we observed complete protection against intraperitoneal challenge with ten times the LD50 of virulent HH0809 strain in mice that were injected intraperitoneally with 0.5 ml rabbit anti-GST-PRN serum. No survivors were observed in mice that received either rabbit anti-GST serum or PBS alone. [Conclusion] The recombinant PRN protein had strong immunogenicity against Bb infection.