title: Sm21.6 a novel EF-hand family protein member located on the surface of Schistosoma mansoni adult worm that failed to induce protection against challenge infection but reduced liver pathology.
abstract: Schistosomiasis continues to be a significant public health problem that affects 200 million people worldwide. This is one of the most important parasitic diseases, and one whose effective control is unlikely in the absence of a vaccine. In this study, we have isolated a cDNA clone encoding the Schistosoma mansoni Sm21.6 protein that has 45% and 44% identity with Sm22.6 and Sj21.7 EF-hand containing antigens, respectively. Confocal microscopy analysis revealed that Sm21.6 is a membrane-associated protein localized on the S. mansoni adult worm. Mouse immunization with rSm21.6 induced a mixed Th1/Th2 cytokine profile and no protection against infection. However, vaccination with rSm21.6 reduced by 28% of liver granuloma numbers, 21% of granuloma area and 34% of fibrosis. Finally, rSm21.6 was recognized by sera from individuals resistant to reinfection compared with patients susceptible to reinfection and this molecule should be further studied as potential biomarker for disease resistance. In conclusion, Sm21.6 is a new tegument protein from S. mansoni that plays an important role in reducing pathology induced by parasite infection.
authors.affiliation: Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Pampulha, Belo Horizonte 31270-901, MG, Brazil.
authors.forename: Debora O
authors.initials: DO
authors.lastname: Lopes
authors.forename: Leonardo F
authors.initials: LF
authors.lastname: Paiva
authors.forename: Mauricio A
authors.initials: MA
authors.lastname: Martins
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Cardoso
authors.forename: Matheus A
authors.initials: MA
authors.lastname: Rajão
authors.forename: Jean M
authors.initials: JM
authors.lastname: Pinho
authors.forename: Marcelo V
authors.initials: MV
authors.lastname: Caliari
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Correa-Oliveira
authors.forename: Samantha M
authors.initials: SM
authors.lastname: Mello
authors.forename: Luciana C C
authors.initials: LC
authors.lastname: Leite
authors.forename: Sergio C
authors.initials: SC
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D002462:Cell Membrane / Q000737:chemistry; D016207:Cytokines / Q000378:metabolism; D020832:EF Hand Motifs; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008099:Liver / Q000473:pathology*; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D016052:Protozoan Vaccines / Q000235:genetics / Q000276:immunology*; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000276:immunology / Q000517:prevention & control*; D017386:Sequence Homology, Amino Acid; D012720:Severity of Illness Index
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016207:Cytokines; D008565:Membrane Proteins; D015800:Protozoan Proteins; D016052:Protozoan Vaccines