Formalin-inactivated vaccine provokes cross-protective immunity in a mouse model of human enterovirus 71 infection.

Human enterovirus 71 (HEV71) has emerged as a major cause of epidemics of hand, foot and mouth disease associated with severe neurological sequelae in the Asia-Pacific region. In this study, a passive protection mouse model was used to evaluate the protective efficacy of formalin-inactivated HEV71 vaccines derived from a Chinese C4 genotype strain. Pregnant mice were immunised using a prime/boost strategy and ≥50U of vaccine protected five-day-old pups from lethal challenge with a mouse-adapted (B3 genotype) strain of HEV71. Immunised mice developed a neutralising antibody response to both the immunising C4 strain and to the mouse-adapted strain. Mice born to immunised dams showed significantly less myositis and reduced viral loads in tissues.

[Expression of hepatitis B surface antigen gene in ginseng cell].

The recombinant plasmid pBIBSa containing the HBsAg DNA fragment was transferred into Agrobacterium tumefaciens strain LBA4404 directly. Ginseng cells were co-cultivated with Agrobacterium tumefaciens carrying pBIBSa. The ginseng cell lines carrying HBsAg-S gene were obtained. Transgenic cells were checked for the presence of target gene using PCR and RT-PCR. Samples containing the target gene showed a clear band at the site of 700 bp by agarose electrophoresis analysis (Figs. 2, 3). Expression levels determined by ELISA showed maximum expression levels of 184 ng HBsAg/g FW and 0.009% of the total soluble protein. HBsAg in ginseng cells were located both on the membrane and in the nuclei (Fig. 4).