biostudies-literatureUnknown9(1)Mo ZQImmobilization antigens (i-antigens) are surface membrane proteins that are widely recognized to be the ideal candidates as vaccines antigens for immunization against Cryptocaryon irritans. In this study, we cloned a putative i-antigen gene from C. irritans, which was expressed in all three stages of the C. irritans life-cycle, and localized primarily to the cell surface. The recombinant GDCI3 i-antigen was expressed and purified using the free-living ciliate, Tetrahymena thermophila as an expression system. The purified recombinant protein was recognized by rabbit anti-C. irritans antiserum and was capable of eliciting immobilizing antibodies in rabbits and fish suggesting that the antigen itself was correctly folded. Following immunization and parasite challenge, groupers vaccinated withScientific reports1029https://www.ebi.ac.uk/biostudies/studies/S-EPMC6355922biostudies-literatureCharacterization and immune regulation role of an immobilization antigen from Cryptocaryon irritans on groupers.PMC6355922Cassidy-Hanley DMMo ZQLi AXDan XMXu SLi YWKolbin DFricke JMClark TGfalseCharacterization and immune regulation role of an immobilization antigen from Cryptocaryon irritans on groupers.Immobilization antigens (i-antigens) are surface membrane proteins that are widely recognized to be the ideal candidates as vaccines antigens for immunization against Cryptocaryon irritans. In this study, we cloned a putative i-antigen gene from C. irritans, which was expressed in all three stages of the C. irritans life-cycle, and localized primarily to the cell surface. The recombinant GDCI3 i-antigen was expressed and purified using the free-living ciliate, Tetrahymena thermophila as an expression system. The purified recombinant protein was recognized by rabbit anti-C. irritans antiserum and was capable of eliciting immobilizing antibodies in rabbits and fish suggesting that the antigen itself was correctly folded. Following immunization and parasite challenge, groupers vaccinated with2019-01-01T00:00:00Z2019 Jan2026-05-03T17:03:34.754Z2019-03-26T22:50:36ZS-EPMC63559223070529210.1038/s41598-018-25710-3