铜绿假单胞菌重组Bb-OprI疫苗免疫及PA01株感染后小鼠脾细胞因子IL-17和Treg的变化

摘要

目的:研究铜绿假单胞菌重组Bb-Opd疫苗免疫及PA01株攻击后小鼠产生的保护力,及脾细胞因子IL-17和Treg的变化.方法:将5×109 CFU的Bb-OprI疫苗灌胃接种BALB/c鼠,每周3次,连续3周;于初次接种后4周,将5×106 CFU的PA01株滴鼻攻击小鼠,攻击后2周处死小鼠,分离肺组织和脾脏,培养肺组织的细菌并进行菌落计数,以铜绿假单胞菌抗原(PaAg)诱导培养脾细胞,PCR扩增IL-17和Foxp3基因.结果:Bb-OprI疫苗组小鼠的肺组织细菌计数(0.46±0.09)×108 CFU明显低于空载体对照组(5.42±0.79)× 108 CFU和Bb对照组(6.20±0.95)× 108 CFU (P＜0.01),从疫苗组小鼠的脾细胞DNA可扩增出380 bp的IL-17和250 bp的Foxp3基因.结论:重组Bb-OprI疫苗可诱导小鼠产生Th17和Treg免疫应答,从而抵抗PA01株感染并维持免疫稳态.%Objective:To study the protection and changes of splenocyte cytokine IL-17 and regulatory T cell (Treg) in mice immunized with recombinant Bb-OprI vaccine against Pseudomonas aeruginosa and challenged with PA01 strain.Methods:BALB/c mice were vaccinated intragastrically with 5×109 CFU of Bb-Opd vaccine 3 times a week for 3 weeks.4 weeks after the first vaccination,mice were challenged intranasally with 5× 106 CFU of PA01 strain.At the 2nd week after the challenge,all mice were sacrificed to separate their lungs and spleens.Bacteria in lung were incubated and the numbers of colonies were enumerated.The splenocytes were cultured by induction with P.aeruginosa antigen(PaAg).The IL-17 and Foxp3 genes of splenocytes were amplified by PCR.Results:The quantity of bacterial colonies in lung of Bb-OprI vaccine group[(0.46±0.09)×108 CFU] was markedly lower than that of vector control group[(5.42±0.79)×108 CFU] and Bb control group[(6.20±0.95)×10s GFU].The IL-17 gene with 380 bp and the Foxp3 gene with 250 bp could be amplified from the DNA of splenocyte in the mice of vaccine group.Conclusion:The recombinant Bb-OprI vaccine may lead to Th17 and Treg immune response in mice against the infection of PA01 strain,and maintain the immune homeostasis.