Oral immunization of mice with recombinant Lactococcus lactis expressing porcine transmissible gastroenteritis virus spike glycoprotein

Abstract

Lactococcus lactis NZ9000 was selected as an antigen delivery vehicle for mucosal immunization against porcine transmissible gastroenteritis virus (TGEV) infection. An approximately 70 kDa fragment of the N-terminal globular domain of the spike (S) protein (SN protein) from the coronavirus TGEV was used as the transmissible gastroenteritis virus antigen model. Recombinant L. lactis, expressing the SN protein, was constructed with the pNZ8112 plasmid. Expression and localization of the transcribed SN protein from the recombinant LNZ9000- rTGEV-SN were detected via SDS-PAGE, Western blot, and immunofluorescence. BALB/c mice, orally immunized with LNZ9000-rTGEV-SN, produced local mucosal immune responses against TGEV. The induced antibodies demonstrated neutralizing effects on TGEV infection. These data indicated that the recombinant L. lactis could be a valuable tool in the development of future vaccines against TGEV.