河豚毒素实验疫苗的不同剂量对免疫效应的影响

Influence of immunization dose schemes on the immune response to anti-tetrodotoxin vaccine

目的 为提高河豚毒素抗毒实验疫苗的效价 ,探索不同免疫剂量对免疫反应的影响。方法 以河豚毒素 (TTX)与中国鲎血蓝蛋白 (TTH)的化学偶联物TTX TTH免疫Balb/c小鼠 ,比较高低不同免疫剂量 (分别为每次 10 0和 2 5 μg)对抗体质量和疫苗的抗毒效价的影响。以血清抗体质量和TTX攻毒效果检验疫苗的效价。结果 低剂量组的抗体质量升速比高剂量组快。两者相比 ,单次抗TTX中毒效价 :半数活存剂量分别为 16×LD和 11×LD ,最大耐受剂量分别为 2 6×LD和 2 2×LD ;累积抗毒效价 :半数动物分别可累计耐受 4 0×LD和 2 2×LD以上 ,测得最大累计耐受剂量分别为 10 4×LD和 90×LD。结论 TTX的实验疫苗在不同免疫剂量方案均有效预防了TTX的攻毒。低剂量组比高剂量组有更好的抗体质量、单次抗毒效价和累积抗毒效价。

Objective To study the relationship between the immune response of anti-tetrodotoxin vaccine, including its dose-response, and to select optimal immunization dose so as to enhance antitoxic effect of the anti-tetrodotoxin vaccine. Methods Tetrodotoxin (TTX) was coupled to Tachypleus tridentatus hemocyanin (TTH) chemically to form artificial antigen (TTX-TTH), and with which Balb/c mice were immunized.Influence of different immunization doses [100 μg as the higher (H) and 25 μg as the lower (L) dose group] on the protective effects of TTX vaccine was compared.The quality of antisera and effects of vaccine in anti-TTX poisoning were observed. Results The sera antibody quality increased more quickly in group L than that in group H after immunization.The dose at which the half of immunized mice survived when challenged once with TTX were 16×LD (1 LD=13.5μg/kg, ip) in group L and 11×LD in group H.When TTX was used time and again, the half of immunized mice could tolerate as high as 40×LD and 22×LD of accumulated dose, and the maximum tolerable cumulated dose was 104×LD and 90×LD for group L and H respectively.The scheme L was better both in antibody quality and effect of protecting against TTX toxicity than that in scheme H. Conclusions The experimental vaccine of TTX could effectively protect animal from TTX intoxication.The lower immunization dose in this study is selected as the optimal immunization scheme.