To assay the immunological effect of rabies virus glycoprotein and nucleoprotein bivalent DNA vaccine and IL 18 on dogs. The double gene vector pIGN alone or in combination with IL 18 in physiological saline or mixed with span glycerol were used to inoculate dogs in quadriceps. Each dog was injected with a dose of 200μg/mL for two times at 2 weeks intervals. The third booster injection was carried out two weeks later by either the same DNA vaccine or a third dose of human inactivated rabies vaccine. Specific immune response was assayed by titration of specific antibodies, neutralizing antibodies and lymphocyte transformation assay. Results showed that (1) the booster injection stimulated a significant anamnestic response in all groups. However, there was no significant difference between groups although pIGN pIIL18 induced higher cell mediated immunity than those without pIIL18; (2) there was no difference in immunological response between the span glycerol DNA vaccine and the DNA vaccine in physiological saline; (3) high immune response could be swiftly induced by a third dose of concentrated rabies vaccine booster in the group primed twice with DNA vaccine. All these indicated that the bivalent DNA vaccine can be applied to immunize dogs in the form of naked plasmids or in the form of mixture with pIIL18. It was demonstrated that bivalent DNA vaccine has the potential in place of inactivated and attenuated vaccines.

Recombinant monogene and double gene expression vectors pIG-neo, pIN-neo, pVG, pVN, pIGN and pVGN were constructed by inserting the G and N gene into pIRES1neo and pVAX1, respectively. Span-glycerol was chosen as adjuvant and mixed with the plasmids to form DNA vaccine. Nine groups of mice were immunized with a dosage of 100 #mu#L(0.5g/L) of plasmids pIRES1neo, pIG-neo, pIN-neo, pIGN, pIG+pIN, pVAX1, pVG, pVN and pVGN, respectively, for 3 times at 14 days intervals. Indirect ELISA and neutralization were employed to determine the immunological response. Results showed that: (1) After 3 times of immunization, seroconversion occurred in all groups excepting negative controls. (2)Antibody level went up swiftly 14 days after the third injection of DNA vaccine. (3)The immunological effect of DNA vaccines based on the pIRES1neo was overally better than those based on the pVAX1. Of all the vaccines, the double gene expression vector pIGN haboring both the glycoprotein and the nucleoprotein cDNAs was the best. The antibody level it stimulated was significantly higher than the others. (4)The protective rate against the challenge of 7.5 LD_(50) CVS was 89%. It indicated that it was worthy being assayed in dogs.

AIMTo clone the canine IL-18 cDNA and to explore the immunological effectiveness of canine IL-18 as an adjuvant of genetic vaccine.METHODSCanine leukocytes were separated from peripheral blood stimulated with ConA for 5-12 h. The full length cDNA of canine IL-18 was amplified by RT-PCR using leukocyte mRNA as a template. IL-18 cDNA was cloned into pMD18-T. Sequencing result showed that the full length cDNA was 582 bp, encoding 193 amino acids, which was identical with that published. The eukaryotic expression vector pIIL18 was constructed. Dogs were inoculated in mixture form of pIGneo and pIIL18.RESULTSCanine IL-18 cDNA was successfully cloned and eukaryotic expression vector pIIL18 was constructed. The immunological assay result showed that the anti-rabies virus-specific antibody level of the group immunized with mixture of pIIL18 and pIGneo was obviously lower than that of the group immunized with pIGneo alone, but the level of cellular immunity of the former was higher than the latter.CONCLUSIONCanine IL-18 can enhance cellular immunity but at the same time suppress humoral immunity, which lays the foundation for IL-18 as an adjuvant of genetic vaccine.

简要介绍了猪的副黏病毒病，包括“蓝眼病’，(blue eye disease)、尼帕病毒病(Nipah virus disease)和梅那哥病毒病(Menangle virus disease)的病原学、流行病学、发病机理及该病的诊断和防制措施。