Schistosoma japonicum: protective immunity induced by schistosomulum-derived cells in a mouse model.
We previously reported that immunization with intact live cells from schistosomula of Schistosoma japonicum (S.j) partially protected the Kunming strain of mice from challenge infection. In the present work, 2 immune protective experiments were designed to further validate the protective effect induced by this type of vaccine and to optimize the immunization protocol, including the number of inoculations and parasite stages from which immunogenic cells were derived. Three antigens derived from 18-day-old postinfection live (LLC) and dead (DLC) larval worm cells and from dead 42-day-old postinfection adult worm cells (DAC) were used as immunogens. Our results demonstrate that live cells from 18-day-old worms are capable of inducing significant protection in mice using a murine-Sj challenge model as shown by reduction rates of worm recoveries and egg burdens. The development of adult worms was stunted. A Th1-biased immune response was reflected in the protected groups as evidenced by the ratio of IgG2a/IgG1. A 38-kDa polypeptide was recognized by sera from LLC immunized animals. We demonstrate that live parasite cells are a source of novel protective antigens that can be exploited for vaccine development.
Cell & Molecular Biological Experiment Center, Department of Parasitology, Xiangya School of Medicine, Central South University, Tongzipo Road 172, Changsha, Hunan 410013, PR China.
Liting
L
Cai
Tiebing
T
Zeng
Qingren
Q
Zeng
Benwen
B
Li
Xuechi
X
Lin
Yanfei
Y
Gong
Wei
W
Liu
Zuping
Z
Zhang
Shunke
S
Zhang
D000818:Animals; D000909:Antibodies, Helminth / Q000096:biosynthesis* / Q000097:blood; D000947:Antigens, Helminth / Q000276:immunology*; D015153:Blotting, Western; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006099:Granuloma / Q000469:parasitology / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D007106:Immune Sera / Q000737:chemistry / Q000276:immunology; D007117:Immunization, Secondary / Q000379:methods / Q000592:standards; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood; D007814:Larva / Q000166:cytology / Q000276:immunology; D008099:Liver / Q000469:parasitology / Q000473:pathology; D051379:Mice; D011817:Rabbits; D012549:Schistosoma japonicum / Q000166:cytology / Q000276:immunology*; D012554:Schistosomiasis japonica / Q000276:immunology / Q000517:prevention & control*; D014611:Vaccination / Q000379:methods* / Q000592:standards
D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D007106:Immune Sera; D007074:Immunoglobulin G