Golden-star nanoparticles as adjuvant effectively promotes immune response to foot-and-mouth disease virus-like particles vaccine.

Virus-like particles (VLPs) have become a hot topic in modern vaccine research because of its safety, facile production, and immune properties. To further enhance the immune effect of VLPs, we synthesized and used gold-star nanoparticles (AuSNs) as adjuvant for vaccine. Foot-and-mouth disease (FMD) VLPs as target antigen were combined with AuSNs. The FMD VLPs-AuSNs complex was characterized through sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blot, ultraviolet light absorption, and morphological measurement analyses. Result indicated that the FMD VLPs-AuSNs complex is non-toxic in different cell lines. AuSNs can effectively promote the entry of FMD VLPs into cells and improve macrophages activation when combined with FMD VLPs compared with FMD VLPs alone. Further animal vaccination and challenge tests revealed that the specific immune response and protection rate of AuSNs adjuvant group is higher than that of conventional mineral oil (ISA206) adjuvant group. AuSNs can effectively improve the immune protection effects of FMD VLPs vaccines, and exhibit potential as a new adjuvant for other vaccines.

Evaluation of cytotoxic and antiviral activities of aqueous leaves extracts of different plants against foot and mouth disease virus infection in farming animals.

Cytotoxic and antiviral activity of aqueous leaves extracts of three plants: Azadirachta indica, Moringa oleifera and Morus alba against Foot and Mouth disease virus (FMDV) were determined using MTT assay (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide). Eight different concentrations of each plant were evaluated. Cytotoxic and antiviral activity of each extract was evaluated as cell survival percentage and results were expressed as Means ± S.D. From the tested plant extracts, Azadirachta indica & Moringa oleifera exhibited cytotoxicity at 200 & 100 µ/ml respectively. In case of antiviral assay, Moringa oleifera showed potent antiviral activity (p<0.05) while Azadirachta indica showed significant antiviral activity in the range of 12.5-50 µ/ml & 50-100 µ/ml respectively. In contrast no anti-FMDV activity in the present study was observed with Morus alba, although all the tested concentrations were found to be safe.

Immune responses to foot-and-mouth disease DNA vaccines can be enhanced by coinjection with the Isatis indigotica extract.

The Isatis indigotica extract is widely used in clinical practice for the treatment of influenza, epidemic hepatitis, epidemic encephalitis B etc. The goal of this study was to investigate whether coinjection of the Isatis indigotica extract with foot-and-mouth disease virus (FMDV) DNA vaccine could increase the protective immune response. Mice were vaccinated twice with either FMDV DNA vaccine plus the Isatis indigotica extract or DNA vaccine alone. Compared with the group of DNA vaccine alone, in the group that received DNA vaccine plus the Isatis indigotica extract was observed a significant increase in not only FMDV-specific antibody response but also T cell proliferation assay. All swine immunized with either FMDV DNA vaccine plus the Isatis indigotica extract or DNA vaccine alone were partially protected from FMDV challenge, but the signs of DNA vaccine plus the Isatis indigotica extract group were less severe than that of DNA vaccine alone. Coinjection of the Isatis indigotica extract with DNA vaccine has adjuvant effect on the immune response against viral pathogens and its application provides an effective strategy to improve the efficacy of DNA vaccines.