Genetic Engineering Group, Experimental Biology Division, Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, Delhi 110054, India.
Vaccine. 2011 Sep 2;29(38):6532-9. doi: 10.1016/j.vaccine.2011.07.005. Epub 2011 Jul 19.
Heat shock proteins serve as important antigens in defense against infectious diseases. Members of HSP70 family, particularly microbial HSP70s have acquired special significance in immunity. In the present study, we evaluated the immunogenicity and protective efficacy of HSP70 of Salmonella enterica serovar Typhi against lethal infection by Salmonella in mice with or without adjuvants. The HSP70 gene was cloned and expressed in Escherichia coli BL21 and purified by affinity chromatography. Immunization of mice with HSP70 either alone or in combination with complete Freund's adjuvant (CFA) resulted in a significant increase in antibody titers as compared to control. Antibody isotyping revealed that HSP70 immunization induces both IgG1 and IgG2a antibodies to a significant extent but a higher IgG1/IgG2a ratio indicates a predominant Th2 response. There was a significant increase in lymphocyte proliferation, and levels of both Th2 and Th1 cytokines in cells isolated from immunized mice as compared to control. Immunization of mice with recombinant HSP70 either alone or in combination with CFA conferred 70-90% protection against lethal infections by Salmonella Typhi Ty2 or Salmonella Typhimurium. However, passive immunization with anti-HSP70 sera induced only partial protection in the immunized mice.
热休克蛋白在防御传染病方面作为重要的抗原。HSP70 家族的成员，特别是微生物 HSP70s，在免疫中具有特殊的意义。在本研究中，我们评估了沙门氏菌肠血清型 Typhi 的 HSP70 对有或没有佐剂的沙门氏菌致死性感染的免疫原性和保护效力。HSP70 基因在大肠杆菌 BL21 中被克隆和表达，并通过亲和层析进行纯化。与对照相比，HSP70 单独或与完全弗氏佐剂（CFA）联合免疫的小鼠，抗体滴度显著增加。抗体分型显示，HSP70 免疫诱导 IgG1 和 IgG2a 抗体的产生，但 IgG1/IgG2a 比值较高表明 Th2 反应占主导地位。与对照相比，从免疫小鼠中分离的淋巴细胞增殖和 Th2 和 Th1 细胞因子水平显著增加。单独用重组 HSP70 或与 CFA 联合免疫的小鼠对沙门氏菌 Typhi Ty2 或沙门氏菌 Typhimurium 的致死性感染的保护率为 70-90%。然而，用抗 HSP70 血清进行被动免疫只能在免疫小鼠中诱导部分保护。
