Comparison of the immune responses induced by oral immunization of mice with Lactobacillus casei-expressing porcine parvovirus VP2 and VP2 fused to Escherichia coli heat-labile enterotoxin B subunit protein.
The major structural protein VP2 of porcine parvovirus (PPV) was used as the model parvovirus antigen, which has been expressed in Lactobacillus casei fusing with Escherichia coli heat-labile enterotoxin B subunit (LTB) as mucosal adjuvant. The VP2-LTB DNA fragment was cloned into vector pPG611 or pPG612 to generated inducible surface-displayed and secretion expression systems based on xylose promoter, designated as rLc:pPG611-VP2-LTB (recombinant L. casei) and rLc:pPG612-VP2-LTB, respectively. Expression of the fusion protein was verified by SDS-PAGE, Western blot immunofluorescence and electron microscopy. It was observed that the level of IgG or sIgA from mice orally immunized with VP2-LTB was higher than that from mice received VP2 and negative control, which demonstrated significantly statistically different. Especially, the titer of IgG or sIgA in mice immunized with rLc:pPG612-VP2-LTB is the highest in this study. In summary, LTB as mucosal adjuvant was able to effectively facilitate induction of mucosal and systemic immunity by L. casei-expressing VP2 fusion protein.
Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, PR China. liudiqiu1980@yahoo.com.cn
Diqiu
D
Liu
Xiangqing
X
Wang
Junwei
J
Ge
Songmei
S
Liu
Yijing
Y
Li
D000284:Administration, Oral; D000818:Animals; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology*; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology*; D004768:Enterotoxins / Q000235:genetics / Q000276:immunology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000276:immunology; D005260:Female; D023061:Gene Order; D056724:Immunity, Humoral; D018928:Immunity, Mucosal; D007114:Immunization; D007780:Lacticaseibacillus casei / Q000235:genetics / Q000276:immunology* / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D010322:Parvoviridae Infections / Q000276:immunology*; D028323:Parvovirus, Porcine / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology
D000956:Antigens, Viral; D036022:Capsid Proteins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D011993:Recombinant Fusion Proteins; C528774:VP2 protein, porcine parvovirus