It is one of the important means to explore the application of antigens to construct engineered bacteria expressing antigen proteins using the lactic acid bacteria expression system.In this study,the signal peptide linked cell wall anchor protein domain sequence(Usp45-3LysM)was fused with GFP protein or the receptor-binding domain(RBD)sequence of S1 protein of Omicron variants respectively using overlap extension PCR technology.The expression vectors pNZ8149-GFP,pNZ8149-2RBD and pNZ8149-3RBD were constructed and transformed into Lactococcus lactis NZ3900,generating the engineered strains for surface displaying GFP,2RBD,or 3RBD.The results showed that the optimal concentration and time of expression of GFP induced by nisin were 20 ng/mL and 20 h,respectively.The results of western blot and indirect immunofluorescence showed that the three target proteins were successfully expressed and displayed on the cell wall of the engineered bacteria,suggesting that the engineered L.lactisthe strain surface displaying SARS-CoV-2 antigen protein had been successfully constructed.This study laid the foundation for the development of a novel oral vaccine based on lactic acid bacteria against the SARS-CoV-2 or other animal viruses and their related products.
维普
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