ABSTRACT
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.
ABSTRACT
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.