title: A phase trial of the oral Lactobacillus casei vaccine polarizes Th2 cell immunity against transmissible gastroenteritis coronavirus infection.
abstract: Transmissible gastroenteritis coronavirus (TGEV) is a member of the genus Coronavirus, family Coronaviridae, order Nidovirales. TGEV is an enteropathogenic coronavirus that causes highly fatal acute diarrhoea in newborn pigs. An oral Lactobacillus casei (L. casei) vaccine against anti-transmissible gastroenteritis virus developed in our laboratory was used to study mucosal immune responses. In this L. casei vaccine, repetitive peptides expressed by L. casei (specifically the MDP and tuftsin fusion protein (MT)) were repeated 20 times and the D antigenic site of the TGEV spike (S) protein was repeated 6 times. Immunization with recombinant Lactobacillus is crucial for investigations of the effect of immunization, such as the first immunization time and dose. The first immunization is more important than the last immunization in the series. The recombinant Lactobacillus elicited specific systemic and mucosal immune responses. Recombinant L. casei had a strong potentiating effect on the cellular immunity induced by the oral L. casei vaccine. However, during TGEV infection, the systemic and local immune responses switched from Th1 to Th2-based immune responses. The systemic humoral immune response was stronger than the cellular immune response after TGEV infection. We found that the recombinant Lactobacillus stimulated IL-17 expression in both the systemic and mucosal immune responses against TGEV infection. Furthermore, the Lactobacillus vaccine stimulated an anti-TGEV infection Th17 pathway. The histopathological examination showed tremendous potential for recombinant Lactobacillus to enable rapid and effective treatment for TGEV with an intestinal tropism in piglets. The TGEV immune protection was primarily dependent on mucosal immunity.
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang, 150030, People's Republic of China.
authors.forename: Xinpeng
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang, 150030, People's Republic of China.
authors.forename: Xingyu
authors.initials: X
authors.lastname: Hou
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang, 150030, People's Republic of China.
authors.forename: Lijie
authors.initials: L
authors.lastname: Tang
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang, 150030, People's Republic of China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Agricultural High Technology Department, China Rural Technology Development Center, Beijing, 100000, People's Republic of China. maguangpeng1977@163.com.
authors.forename: Guangpeng
authors.initials: G
authors.lastname: Ma
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang, 150030, People's Republic of China. yijingli@163.com.
authors.forename: Yijing
authors.initials: Y
authors.lastname: Li
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D002478:Cells, Cultured; D005759:Gastroenteritis / Q000276:immunology / Q000517:prevention & control*; D018928:Immunity, Mucosal / Q000276:immunology; D007114:Immunization; D007070:Immunoglobulin A / Q000276:immunology; D020381:Interleukin-17 / Q000096:biosynthesis / Q000276:immunology; D007780:Lacticaseibacillus casei / Q000276:immunology*; D013552:Swine; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*; D051195:Toll-Like Receptor 2 / Q000096:biosynthesis; D051197:Toll-Like Receptor 4 / Q000096:biosynthesis; D051217:Toll-Like Receptor 9 / Q000096:biosynthesis; D005760:Transmissible gastroenteritis virus / Q000276:immunology*; D014405:Tuftsin / Q000235:genetics; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D001428:Bacterial Vaccines; D007070:Immunoglobulin A; D020381:Interleukin-17; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D014765:Viral Vaccines; D014405:Tuftsin
keywords: Lactobacillus casei vaccine; Phase trial; T helper cell; Transmissible gastroenteritis coronavirus