Genetically engineered bacterial-like particles induced specific cellular and humoral immunity as effective tick-borne encephalitis virus vaccine

Tick-borne encephalitis(TBE)is a natural focal disease with fatal encephalitis induced by tick-borne encephalitis virus(TBEV),seriously threatening human and public health.Protection of TBE depends on vaccination with inactivated vaccine,which requires high cost and multiple immunizations.Here,we construct genetically engineered bacterial-like particles(BLPs)as an effective TBEV vaccine with simplified immunizations and improved immune efficacy.The TBEV BLPs involve the combination of the gram-positive enhancer matrix from Lactococcus lactis,and TBEV envelope(E)protein expressed by genetically engineered recombinant baculovirus.The prepared TBEV BLPs can effectively stimulate the activation of dendritic cells to present the TBEV E proteins to T and B cells,leading to strong and durable cellular and humoral immune responses in mice.Surprisingly,the serum levels of specific IgG antibodies in mice remain about 10^(6)at 6 months after the secondary immunization.Overall,the TBEV BLPs can be used as a potent vaccine candidate,laying the foundation for developing novel TBEV genetically engineered vaccines.

Preparation and Application on the Inactivated Bacterins of Yellow and White Scour of Piglets

Pathogenic Escherichia coli strains were isolated from yellow and white scour samples in pig farms. The strains were used to make autologous inactivated bacterins,and the bacterins were applied to multiple infected farms. The results showed that in the group of inactivated bacterins,the infected piglet number was less,the course of disease was shorter and the symptoms was milder. The piglet E. coli inactivated bacterins could significantly reduced morbidity of yellow and white scour of piglets,the preventive effects of E. coli autologous inactivated bacterins against yellow and white scour of piglets were much better than that of genetically engineered vaccines.