Studies on Mucosal Immunity Induced by Transmissible Gastroenteritis Virus Nucleocapsid Protein Recombinant Lactobacillus casei in Mice and Sow

• Published in: Agricultural sciences in China 2009-02, Vol.8 (2), p.231-237
• Main Authors: Wang, Gui-Hua, Hou, Xi-Lin, Yu, Li-Yun, Liu, Jian-Kui, Wei, Chun-Hua
• Format: Article
• Language: English
• Subjects: 干酪乳杆菌; 怀孕母猪; 核衣壳蛋白; 猪传染性胃肠炎病毒; 粘膜免疫; 重组N蛋白; 间接免疫荧光试验
• ISSN: 1671-2927; 1671-2927
• DOI: 10.1016/S1671-2927(09)60031-6

Mucosal immunity plays an important role in protecting pigs against transmissible gastroenteritis virus （TGEV） infection. To elicit mucosal immune response against TGEV, we developed a surface antigen display system using the poly-γ- glutamate synthetase A （pgsA） protein of Bacillus subtilis as an anchoring matrix to express recombinant fusion proteins of pgsA and nucleocapsid protein of TGEV in Lactobacillus casei. Surface location of fusion protein was verified by ELISA and indirect immunofluorescence test. Oral and intranasal inoculations of pregnant sow and mice with recombinant L. casei resulted in high levels of serum immunoglobulin G （IgG） and secretory immunoglobulin A （slgA） against recombinant N protein as demonstrated by ELISA. More importantly, the level of specific slgA in colostrum significantly increased compared with that of IgG. The serum IgG levels of the piglets increased after suckling colostrum produced by sows was previously inoculated with recombinant L. casei. These results indicate that immunization with recombinant L. casei expressing TGEV N protein on its surface elicited high levels of specific slgA and circulating IgG against TGEV N protein.