[Protective effects of co-immunization with SjCTPI-Hsp70 and interleukin-12 DNA vaccines against Schistosoma japonicum challenge infection in water buffalo].
OBJECTIVE
To induce protective effect of co-immunization with S. japonicum triose-phosphate isomerase fused to heat shock protein 70 (SjCTPI-Hsp70) plasmid and interleukin-12 (IL-12) DNA vaccines against Schistosoma japonicum (Chinese strain) infection in water buffalo.


METHODS
Forty-five 8-10 months-old water buffalo from a nonendemic area were divided into three treatment groups each with fifteen buffalo: experimental group A (SjCTPI-Hsp70+IL-12, 300 microg), experimental group B (SjCTPI+IL-12, 300 microg), and control group C (pVAX+IL-12, 300 microg). All buffalo were immunized with a series of 3 intramuscular injections administered once every four weeks. Twenty-eight days postvaccination, water buffalo were percutaneously challenged with 1000 S. japonicum cercariae. Fecal examinations were conducted two days prior, one day prior, and on perfusion day, and the number of hatching miracidia and eggs per gram feces were recorded. Fifty-six days post-infection, the buffalo were sacrificed and perfused via the descending aorta. The recovered adult worms and eggs in liver tissue were counted.


RESULTS
Groups A and B showed a worm reduction rate of 51.2% and 41.5% (chi2=1.89, P>0.05)), female worm reduction of 48.9% and 44.7% (chi2=0.35,P>0.05), fecal egg reduction of 52.1% and 38.3% (chi2=3.84,P<0.05), a reduction of miracidia-hatching rate by 52.1% and 33.2% (chi2=7.30, P<0.01), and liver egg reduction of 61.5% and 42.0% (chi2=7.61 , P<0.01), respectively.


CONCLUSIONS
Co-immunization with SjCTPI-Hsp70 and IL-12 DNA vaccines induces protective immunity against S. japonicum in water buffalo.
Yu
Xin-Ling
XL
Hunan Institute of Parasitic Disease, Yueyang 414000, China.
He
Yong-Kang
YK
Xiong
Tie
T
Zhao
Ya-Qin
YQ
Shi
Meng-Zhi
MZ
Zhou
Jie
J
Liu
Zong-Chuan
ZC
Luo
Xin-Song
XS
Fu
Xiao
X
He
Hong-Bin
HB
Harn
D A
DA
Li
Yue-Sheng
YS
D000818:Animals; D002020:Buffaloes / Q000469:parasitology*; D005243:Feces / Q000469:parasitology; D005956:Glucose-6-Phosphate Isomerase / Q000235:genetics; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D015801:Helminth Proteins / Q000235:genetics*; D018664:Interleukin-12 / Q000235:genetics; D010273:Parasitic Diseases, Animal / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control; D010957:Plasmids / Q000235:genetics; D012549:Schistosoma japonicum / Q000235:genetics / Q000276:immunology*; D012554:Schistosomiasis japonica / Q000276:immunology* / Q000469:parasitology / Q000517:prevention & control; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology* / Q000627:therapeutic use
D018840:HSP70 Heat-Shock Proteins; D015801:Helminth Proteins; D019444:Vaccines, DNA; D018664:Interleukin-12; D005956:Glucose-6-Phosphate Isomerase