Evaluation Of The Immune Effect Of Sendai Virus HN Gene DNA Vaccine In Infant Mice

ObjectiveHuman parainfluenza virus type 1 (hPIV-1) is a common cause of respiratory infections featuring "croup" and hospitalizations among young children, as well as adult. Sendai virus (SeV) and hPIV-1 have distinct host ranges, whereas their Hemagglutinin-neuraminidase (HN) gene sequences are highly homologous. HN glycoprotein is a major antigen in both SeV and hPIV-1. Therefore, the efficacy of the DNA vaccine harboring HN gene (pcDNA-HN) of SeV was assessed in infant mice with the aim at looking for a new preventive approach to hPIV infections.MethodsMice aged 4-6 weeks were divided into 5 groups at random: inactivated SeV vaccine group, pcDNA3 group, normal saline (N.S.) control group and pcDNA-HN groups (1μg/0.1ml and 5μg/0.1ml). Mice in pcDNA-HN groups were inoculated intramuscularly by the de-endotoxin DNA vaccine, and then boosted twice. Then, the efficacy of the vaccination of mice against a subsequent challenge with SeV was observed by means of mortality rate, target organ indexes, pathological observation of lung tissue, proliferation reaction of B and T cell, IFN-γ assay, hemagglutination inhibition (HI) test, serum IgG antibody assay, and red blood cell immune function.ResultsCompared with the group N.S. and group pcDNA3, the lung indexes of twopcDNA-HN groups were lower and the pathological findings of lung tissue showed significantly different;and the results of the proliferation reaction of B and T cell, IFN-y assay, HI test, serum IgG antibody contents and red blood cell immune function are higher (P<0.05), especially in group pcDNA-HN (5ug/0.1ml), on the other hand, there is no significant difference between the pcDNA-HN groups and group inactivated SeV vaccine (/*>0.05).Conclusion:The satisfied immune result of Sendai HN DNA vaccine suggested it may become a promising candidate vaccine for preventing PIV-1 infection.