Objective:To evaluate preliminarily immunocompetence and immunoprotection of a NMB0315 nucleic acid vaccine,a recombinant protein vaccine and a nucleic acid vaccine plus a recombinant protein vaccine against Neisseria meningitidis serogroup B in mice, and to provide reliable experimental basis for further exploration of the effective immunization methods and pathways of NMB0315 vaccine. Methods:The NMB0315 nucleic acid vaccine [ pcDNA3. 1 (+)/NMB0315 ] and recombinant protein vaccine(pET-30a/NMB0315)were prepared. Female BALB/c mice were inoculated with a NMB0315 DNA vaccine followed by boosting with recombinant protein NMB0315 through intramuscular and intraperitoneal immunization respectively. Next, humoral immunologic response and cellullar immunologic response were detected in female BALB/c mice by ELISA. The survival rate of BALB/c mice was used to evaluate immunoprotection of the vaccines in mice. Results:Specific IgG,IgG1,IgG2a,and sIgA,induced by the NMB0315 DNA vaccine(pNMB0315-CpG),protein NMB0315 vaccine(rNMB0315-FA),NMB0315 DNA vaccine prime-protein boost at week 8, were detected by indirect ELISA,the A450 values were up to(0. 505±0. 042,0. 513±0. 022,0. 342±0. 017,0. 250±0. 015),(0. 823± 0. 061,0. 807±0. 045,0. 596±0. 027,0. 450±0. 028)and(0. 694±0. 053,0. 711±0. 032,0. 455±0. 021,0. 386±0. 024)respectively, which was significantly higher than the PBS control(P<0. 05). The antibody level of protein vaccine was significantly higher than the nucleic acid vaccine group and combined immunization group ( P<0. 05 ) . The stimulation index and IFN-γ level of combined immunization group were significantly higher than the protein vaccine group and nucleic acid vaccine group(P<0. 05). The bactericidal titer of nucleic acid vaccine group, protein vaccine group and combined immunization group reached 1 :64, 1 :128 and 1 :128 respectively,and the protection rates were 70%,95% and 80% respectively. The IgG2a/IgG1 ratios of the nucleic acid vaccine group, the recombinant protein vaccine group and the combined immunization vaccine group were all less than 1 at week 2, 4, 6, 8. Conclusion:The humoral immunity effects( including mucosal immune) induced by the NMB0315 vaccines form high to low were as follows:the recombinant protein vaccine group, the combined immunization vaccine group, the nucleic acid vaccine;and the cellular immune effects from high to low were as follows:the combined immunization vaccine group, the nucleic acid vaccine group, the recombinant protein vaccine group;The protection effects induced by the NMB0315 vaccines in BALB/c mice within 72 hours from high to low were as follows:the recombinant protein vaccine group, the combined immunization vaccine group, the nucleic acid vaccine group.%目的:初步探讨和评价NMB0315核酸疫苗、重组蛋白疫苗及核酸疫苗+重组蛋白疫苗联合免疫诱导小鼠产生的特异性体液/细胞免疫应答水平及其免疫保护效果,为进一步探索NMB0315疫苗有效的免疫方法和途径提供实验依据.方法:大量制备核酸疫苗[pcDNA3.1(+)/NMB0315]和重组蛋白疫苗(pET-30a/NMB0315),采用核酸初免-蛋白加强的方法联合免疫或分别免疫雌性BALB/c小鼠,测定特异性体液/细胞免疫应答水平、免疫血清体外杀菌效价,观察疫苗对感染B群脑膜炎球菌小鼠的免疫保护效果.结果:NMB0315核酸疫苗组(pNMB0315-CpG)、蛋白疫苗组(rNMB0315-FA)及联合免疫疫苗组(pNMB0315-CpG+rNMB0315-FA)诱导的血清特异性IgG、IgG1、IgG2a及生殖道灌洗液中特异性sIgA水平在第八周达到峰值,A450值分别为(0.505±0.042、0.513±0.022、0.342±0.017、0.250±0.015)、(0.823±0.061、0.807±0.045、0.596±0.027、0.450±0.028)和(0.694±0.053、0.711±0.032、0.455±0.021、0.386±0.024),明显高于PBS对照组(P<0.01);其中,蛋白疫苗组的抗体水平明显高于联合免疫疫苗组和核酸疫苗组(P<0.05).小鼠脾淋巴细胞刺激指数及IFN-γ水平,联合免疫疫苗组明显高于蛋白疫苗组和核酸疫苗组(P<0.05);核酸疫苗组、蛋白疫苗组和联合免疫疫苗组免疫血清在补体介导下的体外杀菌抗体效价分别为1:64、1:128和1:128,对实验小鼠的免疫保护率分别为70%、95%和80%.免疫2、4、6、8周时,核酸疫苗组、重组蛋白疫苗组和联合免疫疫苗组IgG2a/IgG1比值均小于1.结论:NMB0315疫苗诱导的体液免疫(包括黏膜免疫)效果从高到低为:重组蛋白疫苗组、联合免疫疫苗组、核酸疫苗组;诱导细胞免疫的效果从高到低为:联合免疫疫苗组、核酸疫苗组、重组蛋白疫苗组;NMB0315疫苗对实验小鼠的免疫保护效果从高到低为:重组蛋白疫苗组、联合免疫疫苗组、核酸疫苗组.
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