Parvane Milad, Nazarian Shahram, Kordbache Emad, Fathi Javad, Minae Mohamad Ebrahim, Ramezani Mohammad Reza
Biology Research Center, Faculty of Basic Sciences, Imam Hossein University, Tehran, Iran.
Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Avicenna J Med Biotechnol. 2022 Oct-Dec;14(4):294-302.
Heat Shock Proteins (HSPs) elicit humoral and cellular immune responses. Due to their high sequence homology, they can be developed as a new immunogen for cross prophylactic and vaccination effects against infectious agents such as Enteropathogenic and Enterohemorrhagic (EPEC and EHEC). This study aimed to evaluate the immunogenicity and cross-protective efficacy of rGroEL of () encapsulated in poly lactic-co-glycolic acid (PLGA) nanoparticles against EPEC and EHEC.
Recombinant GroEL was expressed in () and purified using Ni-NTA affinity chromatography. The protein was encapsulated in PLGA by the double emulsion method, and the nanoparticles were characterized physicochemically. BALB/c mice were immunized, and the efficacy of the protein to elicit immune responses was assessed.
Over-expression in led to corresponding 64.5 protein bands in Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). Non-aggregated nanoparticles had a spherical shape with a mean diameter of 194.3±3 and encapsulation efficiency of 89.5±2.5%. Antibody isotyping revealed that GroEL immunization induced both IgG1 and IgG2a antibodies. Moreover, immunization of the mice with recombinant GroEL protein conferred 80 and 60% protection against lethal infections by EPEC and EHEC, respectively. Furthermore, organ burden studies revealed a significant reduction in infection in the immunized mice compared to the non-immunized ones. Passive immunization with anti-GroEL sera also protected 50% of the mice against the lethal doses of EHEC and EPEC strains.
The findings indicated that immunization of the mice with recombinant GroEL of elicited cross-protection against other bacterial infections. This represented the immense potential of GroEL to be developed as a single vaccine against multiple pathogens.
热休克蛋白（HSPs）可引发体液免疫和细胞免疫反应。由于它们具有高度的序列同源性，因此可被开发为一种新型免疫原，用于对肠道致病性和肠道出血性（EPEC和EHEC）等感染因子产生交叉预防和疫苗接种效果。本研究旨在评估包裹于聚乳酸-乙醇酸共聚物（PLGA）纳米颗粒中的重组（）GroEL对EPEC和EHEC的免疫原性和交叉保护效果。
重组GroEL在（）中表达，并通过镍-氮三乙酸亲和层析法进行纯化。采用双乳化法将该蛋白包裹于PLGA中，并对纳米颗粒进行理化特性表征。对BALB/c小鼠进行免疫，并评估该蛋白引发免疫反应的效果。
在（）中的过表达导致在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）中出现相应的64.5 kDa蛋白条带。非聚集纳米颗粒呈球形，平均直径为194.3±3 nm，包封率为89.5±2.5%。抗体分型显示，GroEL免疫诱导产生了IgG1和IgG2a抗体。此外，用重组GroEL蛋白对小鼠进行免疫分别对EPEC和EHEC致死性感染提供了80%和60%的保护。此外，器官负荷研究显示，与未免疫小鼠相比，免疫小鼠的感染显著减少。用抗GroEL血清进行被动免疫也使50%的小鼠免受致死剂量的EHEC和EPEC菌株感染。
研究结果表明，用重组（）GroEL对小鼠进行免疫可引发针对其他细菌感染的交叉保护。这表明GroEL作为一种针对多种病原体的单一疫苗具有巨大的开发潜力。
