ABSTRACT
Objective To investigate whether the defective interfering(DI) particles of Paramyxovirus, Tianjin strain could be used as a candidate adjuvant. Methods DI particles were separated and purified. After being identified, it was equally mixed with the inactivated poliovirus (PV) vaccine. Kunming mice were administered subcutaneously with the mixture, besides we set groups of inactivated PV vaccine containing Al(OH) 3 as an adjuvant, inactivated PV vaccine of which the dose was doubled without any adjuvant, and negative control. Sera were collected in the 14th day after immunization, and the specific antibodies of PV were detected. T/B lymphocyte stimulation indexes(SI) were counted through the lymphocyte proliferation tests. The quantities of IFN-γ/IL-4 produced by the splenocytes which were stimulated again by PV antigen were detected. Results The SI and the quantity of IFN-γof the mice in the group of inactivated PV vaccine combining with DI particles of Paramyxovirus, Tianjin strain were more than other groups. Conclusion DI particles of Paramyxovirus, Tianjin strain could enhance the immune response of inactivated poliovirus, especially the cellullar immunologic response of Th1 type.
ABSTRACT
Paramyxovirus Tianjin strain, a new genotype of Sendal virus, was isolated from the lungs of common cotton-eared marmoset that died of severe respiratory infection in the marmoset colonies. The 19.28% IgM positive rate in the young children with acute respiratory tract infection suggested a close relationship between Tianjin strain and humans. Hemagglutinin-neuraminidase (HN) is its major transmembrane glycoprotein responsible for viral attachment, penetration and release. To clear the relationship between HN structure and function of paramyxovirus Tianjin strain, rHN1, rHN2 and rHN3 overlapping the ectodomain of HN protein were expressed. Their antigenicity and hemaglutination activity, as well as cross reactivity to standard antisera against influenza virus type A, type B were analyzed. The results indicated expressed rHNs have the natural antigenicity.The segment rHN2 possesses more linear epitopes exposed on the surface of the native I-IN protein than found in segments rHN3 and rHN1. The hemagglutination activity of segment rHN3 is higher than that of segments rHN2 and rHN1, and partially dependent on the three-dimensional conformation of HN3 protein. Cross-reactivity between rHNs and standard antisera against influenza virus type A, type B suggested that rHNs might not be the best alternative as specific antigens to detect virus in clinicalserum specimens.