title: Characterization of Schistosoma japonicum CP1412 protein as a novel member of the ribonuclease T2 molecule family with immune regulatory function.
abstract: Schistosome infection typically induces a polarized Th2 type host immune response. As egg antigen molecules play key roles in this immunoregulatory process, clarifying their functions in schistosomiasis would facilitate the development of vaccine and immunotherapeutic methods. Schistosoma japonicum (Sj) CP1412 (GenBank: AY57074.1) has been identified as a new member of the RNase T2 family with immune regulatory functions.
  
  
  
  The expression plasmid Sj CP1412-pET28a was constructed and transformed into bacteria for production of recombinant Sj CP1412 protein (rSj CP1412) via IPTG induction. The RNase activity of Sj CP1412 was predicted by bioinformatic analysis and confirmed by digesting the yeast tRNA with rSj CP1412.C57BL/6j mice were immunized with rSj CP1412, and its immune regulatory effects in vivo and in vitro were investigated. Meanwhile, the relationship between the RNase activity of Sj CP1412 and its immune regulation was observed.
  
  
  
  Sj CP1412 was confirmed as a novel RNase T2 family protein with RNase activity. Immunoblotting and RT-PCR analyses demonstrated Sj CP1412 as a protein exclusively secreted/excreted from eggs, but not cercariae and adult worms. Stimulating RAW264.7 macrophages with rSj CP1412 raised the expression of CD206, Arg-1 and IL-10, which are related to M2 type macrophage differentiation. Stimulating dendritic cells (DCs) with rSjCP1412 failed to induce their maturation, and the recombinant protein also inhibited LPS-stimulated DC maturation. Depletion of Sj CP1412 from soluble egg antigen (SEA) impaired the ability of SEA to induce M2 type polarization of RAW264.7 macrophages. Immunizing mice with rSj CP1412 induced high antibody titers, increased serum IL-4 and TGF-β levels and splenic CD4 + CD25 + Foxp3 + T cells, downregulated serum IFN-γ levels and alleviated the egg granuloma pathology of schistosome infection. In vitro stimulation by rSj CP1412 significantly increased CD4 + CD25 + Foxp3 + T cell numbers in splenocytes of healthy mice. The rSj CP1412 protein with RNase activity inactivated by DEPC failed to induce M2 surface marker CD206 expression in RAW264.7 macrophages.
  
  
  
  The Sj CP1412 protein expressed specifically in S. japonicum eggs is a novel member of the RNase T2 family. Similar to Omega-1 of Schistosoma mansoni, the Sj CP1412 protein drives polarization of the host Th2 immune response, which is dependent on its RNase activity. These data provide new evidence towards understanding the immune regulatory role of RNase T2 family proteins during schistosome infection.
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.
authors.forename: Xue-Dan
authors.initials: XD
authors.lastname: Ke
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.|Medical College, Jiangnan University, Wuxi, 214122, China.|Public Health Research Center, Jiangnan University, Wuxi, 214122, People's Republic of China.|Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Shen
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Song
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China. 1360319846@qq.com.|Medical College, Jiangnan University, Wuxi, 214122, China. 1360319846@qq.com.|Public Health Research Center, Jiangnan University, Wuxi, 214122, People's Republic of China. 1360319846@qq.com.
authors.forename: Chuan-Xin
authors.initials: CX
authors.lastname: Yu
authors.affiliation: Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
authors.forename: Mihoko
authors.initials: M
authors.lastname: Kikuchi
authors.affiliation: Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirayama
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.|Department of Pathology, Nanjing Drum Tower Hospital, Nanjing, 210003, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Gao
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.
authors.forename: Xuren
authors.initials: X
authors.lastname: Yin
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health; Jiangsu Provincial Key Laboratory on Technology for Parasite and Vector Control, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology* / Q000302:isolation & purification; D019295:Computational Biology; D003713:Dendritic Cells / Q000276:immunology; D004722:Endoribonucleases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D007114:Immunization; D007155:Immunologic Factors / Q000378:metabolism; D016753:Interleukin-10 / Q000096:biosynthesis / Q000276:immunology; D015847:Interleukin-4 / Q000096:biosynthesis / Q000276:immunology; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D012549:Schistosoma japonicum / Q000737:chemistry / Q000276:immunology*; D012554:Schistosomiasis japonica / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D000947:Antigens, Helminth; D007155:Immunologic Factors; D016753:Interleukin-10; D015847:Interleukin-4; D004722:Endoribonucleases; C022543:ribonuclease T(2)
keywords: CD4 + CD25 + Foxp3 + T cell; RNase activity; Schistosoma japonicum; Sj CP1412; Th2 polarizaton