Induction of immune responses by a novel recombinant fusion protein of enterovirus A71 in BALB/c mice.

Fusion protein technology is used in biotechnology and medical developments. In this study, recombinant fusion proteins from enterovirus A71 (EV-A71) subgenotype B5, Thailand were designed based two surface proteins (VP1 and VP2) and an internal protein (VP4), and named "VP0" (consisting of VP4-VP2) and "EV71" (consisting of VP4-VP2-VP1), respectively. The recombinant fusion proteins VP0 and EV71 were expressed in insect cells and successfully produced and secreted into the media. Both recombinant fusion proteins were shown to have immunogenic properties in BALB/c mice when formulated with Freund's complete/incomplete adjuvant (FA). Interestingly, EV71 formulated with FA- induced a level of IgG antibodies level similar to that induced by the recombinant protein VP1 formulated with FA (the positive control). Our results showed that VP1 alone is better at eliciting a strong cell-mediated immune response. Nontheless, EV71 formulated with FA was capable of inducing lymphocyte proliferation and increasing the cytokine-related mRNA expression levels of interferon-γ (IFN-γ), interleukin-2 (IL-2), and IL-10 in mice after immunization. Additionally, the number of CD4+ and CD8+ T lymphocyte cells after stimulation with purified EV71 in splenic cell culture showed highly specific CD4+ and CD8+ T-cell production. We suggest that EV71, which consists of VP4-VP2-VP1, could be used as the foundation for developing a novel recombinant fusion protein-based vaccine for EV-A71.

Effective Protection on Acute Liver Injury by Halo Tag-Flanked Recombinant Fibroblast Growth Factor 7.

The drug development of FGF7 has been restricted by its toxicity to the host, low expression, poor stability, and easy degradation. Recent studies have shown that Halo-tag-flanked recombinant human FGF7 can solve the problem of toxicity; however, its biological activity is unknown. This study aimed to explore the activity of Halo-rhFGF7 and rhFGF7 on acute liver injury in vitro and in vivo. The rhFGF7 is expressed with a N-terminal Halo-tag, followed by a tobacco etch virus (TEV) protease cleavage site, in Escherichia coli BL21 (DE3) pLysS in this study. The products could stimulate the proliferation of carbon tetrachloride-damaged L-O2 cells (normal human liver cells); they also inhibited cell apoptosis. Due to the use of the Halo, the protein could be tracked using fluorescence localization. Recombinant protein exerted a protective effect on the acute liver injury model in vitro and in vivo. The MTT assay and Western blot analysis showed that this protective effect is realized through various paths, including promoting proliferation, inhibiting cell apoptosis and anti-inflammatory. In conclusion, Halo-rhFGF7 and rhFGF7 displayed an excellent protective effect on acute liver injury. The present study provided an experimental basis and data support for further research on rhFGF7.