IMMUNOMODULATION OF LACTOBACILLUS PLANTARAM EXPRESSING PORCINE ROTAVIRUS VP6

Rotaviruses are members of the family Reoviridae. Depending on their particular inner capsid protein sequences, porcine rotaviruses are categorized into groups A, B and C. Lactic acid bacteria (LAB) are the common term for bacteria that produce a large amount of lactic acid and ferment carbohydrates. We constructed a Lactobacillus plantarum strain with surface displayed VP6, named NC8-pSIP409-pgsA-VP6-Dcpep The adhesion and invasion ratios of NC8-pSIP409-pgsA-VP6-Dcpep on BMDCs were 36.17% and 2.23%, respectively,which were 1.56 fold and 2.42 fold increased compared with empty vector group. Furthermore, NC8-pSIP409-pgsA-VP6-Dcpep strain harboring a eukaryotic plasmid pValac-GFP was co-cultured with BMDCs for 36h and GFP expression in BMDCs was detected by FCM to determine the delivery efficiency of pValac-GFP. The results showed that the strain could significantly enhance GFP expression in BMDCs (P=0.0110). The mice were immunized using the above strains harboring pValac-GFP and the oral administration resulted in efficient expression of GFP in both PPs andMLN at different times after the last administration. In addition, the NC8-pSIP409-pgsA-VP6-Dcpep strain significantly promoted the differentiation and maturation of DCs, the percentages of IL-4+and IL-17A+ of CD4+T cells in MLN, as well as production of B220+ IgA+ B cells in the PPs.