[Mucosal immunization of recombinant Schistosoma japonicum ferritin].
OBJECTIVE
To subclone and express the gene encoding Schistosoma japonicum ferritin (SjFer) and study its immune protection against challenge infection in mice vaccinated intranasally.


METHODS
The SjFer gene was amplified by PCR, and subcloned into the N-terminal of intein 2 of the pTWIN1 vector. The positive recombinant was screened by PCR, restriction enzyme digestion and sequence analysis. The positive recombinant was transformed into E. coli ER2566. The soluble recombinant fusion protein (rSjFer-intein 2) was expressed in E. coli by induction of low IPTG concentration under low temperature, and analyzed by SDS-PAGE and Western blotting. Mice were immunized intranasally with rSjFer, using chitosan as adjuvant. Two weeks after the third vaccination, challenge infection with S. japonicum cercariae was carried out. Worms and eggs collected from the livers of mice were counted at 42 days after the challenge. Levels of specific antibodies were detected by ELISA before infection.


RESULTS
SjFer was successfully subcloned into pTWIN1 vector and expressed in E. coli. In mice vaccinated intranasally with rSjFer and adjuvant chitosan, the worm reduction rate was 35.51% and the reduction rate of eggs per gram liver tissue (LEPG) was 52.17%. As compared with the control groups, levels of IgG, IgA in sera and SIgA in saliva increased significantly.


CONCLUSIONS
The expressed rSjFer can induce partial protective immunity against S. japonicum infection in mice when they were vaccinated intranasally, with chitosan as adjuvant.
Chen
Li-yu
LY
Faculty of Pathogenic Biology, Xiangya School of Medicine, Central South University, Changsha 410078, China.
Yi
Xin-yuan
XY
Zeng
Xian-fang
XF
Zhang
Shun-ke
SK
McReynolds
Larry
L
D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D001483:Base Sequence; D048271:Chitosan / Q000737:chemistry / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005293:Ferritins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009092:Mucous Membrane / Q000276:immunology*; D011897:Random Allocation; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D012549:Schistosoma japonicum / Q000276:immunology*; D012554:Schistosomiasis japonica / Q000517:prevention & control; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000276:immunology
D000947:Antigens, Helminth; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic; D005293:Ferritins; D048271:Chitosan