title: Tandem repeat recombinant proteins as potential antigens for the sero-diagnosis of Schistosoma mansoni infection.
abstract: The diagnosis of schistosome infection, followed by effective treatment and/or mass drug administration, is crucial to reduce the disease burden. Suitable diagnostic tests and field-applicable tools are required to sustain schistosomiasis control programs. We therefore assessed the potential of tandem repeat (TR) proteins for sero-diagnosis of Schistosoma mansoni infection using an experimental mouse model. TR genes in the genome of S. mansoni were searched in silico and 7 candidates, named SmTR1, 3, 8, 9, 10, 11 and 15, were selected. Total RNA was extracted from S. mansoni adult worms and eggs. Target TR genes were amplified, cloned, and the proteins were expressed in Escherichia coli competent cells. Female BALB/c mice were infected with 100 S. mansoni cercariae and sera were collected each week post-infection for 18 weeks. The levels of IgG antibodies to SmTR antigens were compared to those to soluble egg antigen (SEA) and to soluble worm antigen preparation (SWAP). Sera of infected mice reacted to all the antigens whereas those of naïve mice did not. IgG responses to SmTR1, 3, 9 and 10 were detected at the early stage of infection. Interestingly, antibodies reacting to SmTR3, 9, 10 and 15 dramatically decreased 4 weeks after treatment with praziquantel, while those against SEA and SWAP remained elevated. Our study suggests that TR proteins, especially SmTR10, may be suitable antigens for sero-diagnosis of infection by S. mansoni and are potential markers for monitoring and surveillance of schistosomiasis, including re-infection after treatment with praziquantel.
authors.affiliation: Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors.forename: Yombo Dan Justin
authors.initials: YD
authors.lastname: Kalenda
authors.affiliation: Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kato
authors.affiliation: Laboratory of Molecular Immunology, Department of Animal Resource Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Department of Eco-epidemiology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Fujii
authors.affiliation: Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Nagasaki University Nairobi Research Station, NUITM-KEMRI Project, Nairobi, Kenya. Electronic address: shinjiro@nagasaki-u.ac.jp.
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Hamano
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D000909:Antibodies, Helminth / Q000097:blood* / Q000276:immunology; D000947:Antigens, Helminth / Q000235:genetics / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D004195:Disease Models, Animal; D005260:Female; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011223:Praziquantel / Q000627:therapeutic use; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology*; D012008:Recurrence; D012550:Schistosoma mansoni / Q000187:drug effects / Q000235:genetics*; D012555:Schistosomiasis mansoni / Q000175:diagnosis* / Q000188:drug therapy; D012698:Serologic Tests; D020080:Tandem Repeat Sequences / Q000235:genetics*
chemical_list: D000871:Anthelmintics; D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D015415:Biomarkers; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D011223:Praziquantel
keywords: Animal model; Antibodies; Schistosoma mansoni; Sero-diagnosis; Tandem repeat