title: Characterization and expression of the Schistosoma japonicum thioredoxin peroxidase-2 gene.
abstract: We analyzed proteins that were differentially expressed by 10-day-old schistosomula from 3 different hosts and determined that a functional thioredoxin peroxidase-2 gene has an important antioxidant role in Schistosoma japonicum , which we investigated further. A full-length cDNA encoding the S. japonicum thioredoxin peroxidase-2 (SjTPx-2) had an open reading frame of 681 bp that encoded 226 amino acids with a signal peptide of 24 amino acids. A cDNA encoding SjTPx-2 without the signal peptide sequence was isolated from 42-day-old schistosome cDNAs. Real-time quantitative RT-PCR analysis revealed that SjTPx-2 was upregulated in 7- and 13-day-old schistosomes, while the expression level in females was around 2-fold higher than that in male worms at 42 days. SjTPx was subcloned into pET28a(+) and expressed as both inclusion bodies and supernatant in Escherichia coli BL21 (DE3) cells. Western blotting showed that the recombinant SjTPx-2 (rSjTPx-2) was immunogenic. The purified recombinant protein could form disulfide-bonded dimers and it had peroxidase activity in vitro. An immunoprotection experiment in BALB/c mice showed that vaccination with recombinant SjTPx-2 could induce 31.2% and 34.0% reductions in the numbers of worms and eggs in the liver, respectively. This study suggests that SjTPx-2 may be an important antioxidative enzyme in scavenging ROS, and it may be a potential vaccine candidate or new drug target for schistosomiasis.
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai, 200241, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Hong
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Han
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Fu
authors.forename: Hongxiao
authors.initials: H
authors.lastname: Han
authors.forename: Chunhui
authors.initials: C
authors.lastname: Qiu
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Jianmei
authors.initials: J
authors.lastname: Yang
authors.forename: Yaojun
authors.initials: Y
authors.lastname: Shi
authors.forename: Xiangrui
authors.initials: X
authors.lastname: Li
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Lin
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000975:Antioxidants / Q000378:metabolism*; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D054464:Peroxiredoxins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000302:isolation & purification / Q000378:metabolism; D011817:Rabbits; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction; D012549:Schistosoma japonicum / Q000145:classification / Q000201:enzymology* / Q000235:genetics* / Q000276:immunology; D012554:Schistosomiasis japonica / Q000517:prevention & control; D012737:Sex Factors; D013154:Spleen / Q000166:cytology / Q000276:immunology; D014611:Vaccination
chemical_list: D000276:Adjuvants, Immunologic; D000909:Antibodies, Helminth; D000975:Antioxidants; D007074:Immunoglobulin G; D012333:RNA, Messenger; D054464:Peroxiredoxins