日本血吸虫热休克蛋白60 kDa的免疫原性及保护性研究

目的研究日本血吸虫热休克蛋白60 kDa(SjHSP60)免疫原性,评价其免疫保护性及可能机制。方法通过在线生物信息学软件预测SjHSP60的B细胞表位,随后用SjHSP60免疫BALB/c小鼠后检测特异性抗体水平和淋巴细胞增殖以评估其免疫原性,进一步通过攻击感染实验观察其免疫保护效果;最后分选免疫小鼠的CD4~+CD25~+调节性T细胞(Treg)与CD4~+CD25~-T细胞共培养,通过细胞增殖实验检测CD4~+CD25~+Treg细胞的抑制功能。结果生物信息学预测结果显示,SjHSP60中存在多个B细胞表位的优势区段。SjHSP60可在小鼠体内诱导特异性抗体(P0.01),也可诱导小鼠脾细胞发生增殖(P0.01)和分泌IFN-γ(P0.01);但攻击感染实验显示,SjHSP60免疫小鼠体内虫荷(P0.05)、卵荷(P0.05)均未显著减少。体外共培养实验表明,SjHSP60可显著增强小鼠CD4~+CD25~+Treg细胞的免疫抑制功能(P0.01)。结论SjHSP60对宿主免疫系统可发挥"双刃剑"作用,即在诱导特异性抗感染免疫应答的同时又可增强免疫抑制功能,从而削弱了其免疫保护作用。

Studies on immunogenicity and immunoprotection induced by heat shock protein 60 kDa of Schistosoma japonicum in mice

Objective Objective To evaluate the immunogenicity and immunoprotective effect of heat shock protein 60 kDa (SjHSP60) of Schistosoma japonicum in mice after immunization and challenge infection, and explore the mechanism. Methods Methods B cell/an? tibody?related databases and analysis tools were used to predict B?cell epitopes of SjHSP60. The mice were immunized with the recombinant SjHSP60 and challenged with S. japonicum cercariae. SjHSP60?specific antibodies in serum were detected by ELI? SA. The level of splenocyte proliferation was determined by 3 H?TdR incorporation. Ex vivo suppression assay was performed to in? vestigate the effects of CD4+ CD25+ regulatory T cells (Tregs) induced by SjHSP60. Results Results SjHSP60 possessed multiple pre? dominant regions of B?cell epitopes. SjHSP60 induced a significant increase in both SjHSP60?specific IgG levels (P < 0.01) and splenocyte proliferation (P < 0.01) with a higher IFN?γ production (P < 0.01). However, the immunization with SjHSP60 resulted no significant reduction in adult worms (P > 0.05) and liver?accumulated eggs (P > 0.05) in S. japonicum?infected mice. Ex vivo assay showed that CD4+ CD25+ Tregs from SjHSP60?immunized mice enhanced immunosuppressive activity. Conclusion Conclusion SjH? SP60 has a dual role in host immune system, being involved in the induction of dominant humoral and cellular immune responses as well as in the enhancement of immunosuppression.