[Boost effect of recombinant IL-4 on protection of Schistosoma japonicum cathepsin B DNA vaccine in mice against the parasite].
OBJECTIVE
To investigate the enhancement effect of IL-4 expression plasmid on cathepsin B DNA vaccine of Schistosoma japonicum (Sj) in mice.


METHODS
The recombinant IL-4 plasmid constructed by cloning PCR amplified product of murine IL-4 gene into eukaryotic expression vector pcDNA3.1 was co-injected intramuscularly with Sj cathepsin B expression plasmid DNA to mice as the test group. The other three groups of mice were set up as control including IL-4 expression plasmid, Sj cathepsin B expression plasmid and two vacant vector plasmids. The expression of IL-4 and cathepsin B was visualized by immunohistochemistry. Challenge infection in mice was carried out 3 weeks after the last vaccination and immune protection was assessed by worm and egg reduction rates.


RESULTS
The recombinant mIL-4 plasmid and cathepsin B DNA vaccine were expressed in muscular cells of the vaccinated mice. Immunization with cathepsin B DNA plus recombinant mIL-4 plasmid yielded a 43.2 % of worm reduction rate and a 76.6% of egg reduction rate, showing a significant difference (P<0.01, P<0.05) compared with that of cathepsin B DNA vaccine alone.


CONCLUSIONS
As an adjuvant, IL-4 DNA can improve the protective effect of cathepsin B DNA vaccine in mice against S. japonicum infection.
Chen
Yu-Xiao
YX
Department of Immunology, Xiangya School of Medicine, Central South University, Changsha 410078, China. yuxiaochen008@yahoo.com.cn
Wang
Lin-Xian
LX
Tang
Lian-Fei
LF
Zhang
Shun-Ke
SK
Zhang
Jie
J
Zeng
Xian-Fang
XF
Yi
Xin-Yuan
XY
D000818:Animals; D002401:Cathepsin B / Q000276:immunology* / Q000378:metabolism; D005260:Female; D015847:Interleukin-4 / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D010957:Plasmids / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D012549:Schistosoma japonicum / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology*
D011994:Recombinant Proteins; D019444:Vaccines, DNA; D015847:Interleukin-4; D002401:Cathepsin B