Assessment of recombinant Lactobacillus vector-based expressing IFITM3 protein anti-PRV infection in mice

Pseudorabies virus (PRV) causes high mortality encephalitis in newborn piglets, abortion and stillbirth in sows, resulting in huge economic losses to the swine industry. Interferon-induced transmembrane proteins (IFITMs) play a crucial role in the innate immune response triggered by viral infection. Lactic acid bacteria (LABs) are good candidates for the development of new oral vaccines and are attractive alternatives to attenuated pathogens. "Here we tested the capacity of a LAB vector expressing the IFITM3 protein (r-LAB-I3), delivered by oral gavage, to protect mice against PRV challenge. Furthermore, the r-LAB-I3 treated groups showed markedly diminished levels of viral DNA in brain, lung, spleen and liver tissues, which resulted in protection against brain and lung damage. Moreover, the inhibitory effect of IFITM3 on PRV circumvents the upregulation of inflammatory cytokines. As r-LAB-I3 oral gavage platforms can restrict in various organs and tissues of PRV in mice, recombinant LAB may generate additional innovative and efficient live vector anti-PRV candidates.