IL-18 enhances protective effect in mice immunized with a Schistosoma japonicum FABP DNA vaccine.
Two recombinant plasmids, pVAX/SjFABP and pVAX/mIL-18 containing Schistosoma japonicum 14 kDa fatty acid binding protein (SjFABP) and murine IL-18, were constructed and evaluated for their ability to induce immune responses and to protect against S. japonicum challenge in mice. Mice were intramuscularly immunized twice at three-weekly intervals, and challenged with S. japonicum cercariae at 4 weeks after the last vaccination. All animals vaccinated with pVAX/SjFABP alone or plus pVAX/mIL-18 developed specific anti-SWAP ELISA antibody and T lymphocyte proliferation. Co-injection of pVAX/mIL-18 significantly increased the production of IFN-gamma and IL-2 compared with pVAX/SjFABP alone, indicating that IL-18 enhances the Th1-dominant immune response. The challenge experiment showed that co-injection of plasmid encoding IL-18 significantly enhances protective effect against S. japonicum infection, as demonstrated by worm reduction rates and the hepatic egg reduction rates 45 days post-challenge. These results indicated that IL-18 may become a novel vaccine adjuvant for development of vaccines against schistosomiasis.
Wei
Feng
F
Laboratory of Parasitology, Veterinary Institute, Academy of Military Medical Sciences, Changchun 130062, Jilin Province, China.
Liu
Quan
Q
Zhai
Yujia
Y
Fu
Zhiqiang
Z
Liu
Wensen
W
Shang
Limin
L
Men
Jingtao
J
Gao
Shengyan
S
Lian
Hai
H
Jin
Hongtao
H
Chen
Chen
C
Lin
Jiaojiao
J
Shi
Yaojun
Y
Xia
Zhiping
Z
Zhu
Xing-Quan
XQ
D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D049109:Cell Proliferation; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000276:immunology*; D005260:Female; D007117:Immunization, Secondary; D007273:Injections, Intramuscular; D007371:Interferon-gamma / Q000378:metabolism; D020382:Interleukin-18 / Q000008:administration & dosage / Q000494:pharmacology*; D007376:Interleukin-2 / Q000378:metabolism; D008099:Liver / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D010270:Parasite Egg Count; D010957:Plasmids; D016052:Protozoan Vaccines / Q000235:genetics / Q000276:immunology*; D012549:Schistosoma japonicum / Q000235:genetics / Q000276:immunology*; D012554:Schistosomiasis japonica / Q000276:immunology / Q000517:prevention & control*; D013601:T-Lymphocytes / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*
D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D050556:Fatty Acid-Binding Proteins; D020382:Interleukin-18; D007376:Interleukin-2; D016052:Protozoan Vaccines; D019444:Vaccines, DNA; D007371:Interferon-gamma