Artron Bioresearch (Canada)

Abstract Without approved vaccines and specific treatment, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is spreading around the world with above 20 million COVID-19 cases and approximately 700 thousand deaths until now. An efficacious and affordable vaccine is urgently needed. The Val308 – Gly548 of Spike protein of SARS-CoV-2 linked with Gln830 – Glu843 of Tetanus toxoid (TT peptide) (designated as S1-4) and without TT peptide (designated as S1-5), and prokaryotic expression, chromatography purification and the rational renaturation of the protein were performed. The antigenicity and immunogenicity of S1-4 protein was evaluated by Western Blotting (WB) in vitro and immune responses in mice, respectively. The protective efficiency of it was measured by virus neutralization test in Vero E6 cells with SARS-CoV-2. S1-4 protein was prepared to high homogeneity and purity by prokaryotic expression and chromatography purification. Adjuvanted with Alum, S1-4 protein stimulated a strong antibody response in immunized mice and caused a major Th2-type cellular immunity compared with S1-5 protein. Furthermore, the immunized sera could protect the Vero E6 cells from SARS-CoV-2 infection with neutralization antibody GMT 256. The candidate subunit vaccine molecule could stimulate strong humoral and Th1 and Th2-type cellular immune response in mice, giving us solid evidence that S1-4 protein could be a promising subunit vaccine candidate.

Phytase is a phosphohydrolase considered highly specific for the degradation of phytate to release bound phosphorus for animal consumption and aid in the reduction of environmental nutrient loading. New sources of phytase have been sought that are economically and efficiently productive including the construction of genetically modified (GM) phytase products designed to bypass the costs associated with feed processing. Four monoclonal antibodies (EH10a, FA7, AF9a, and CC1) raised against recombinant Aspergillus niger phyA2 were used to develop a highly specific and sensitive immunochromatographic lateral flow device for rapid detection of transgenic phytase, such as in GM corn. Antibodies sequentially paired and tested along lateral flow strips showed that the EH10a-FA7 antibody pair was able to detect the recombinant yeast-phytase at 5 ng/mL, whereas the AF9a-CC1 antibody pair to GM phytase corn was able to detect at 2 ng/mL. Concurrent to this development, evidence was revealed which suggests that antibody binding sites may be glycosylated.