Takeshi ArakawaTakafumi TsuboiJetsumon SattabongkotKozue SakaoMotomi ToriiTakeshi MiyataUniversity of the RyukyusEhime UniversityMahidol UniversityKagoshima University2018-11-092018-11-092014-01-01Clinical and Vaccine Immunology. Vol.21, No.4 (2014), 561-5691556679X155668112-s2.0-84897939210https://repository.li.mahidol.ac.th/handle/20.500.14594/33462The development of malaria vaccines is challenging, partly because the immunogenicity of recombinant malaria parasite antigens is low. We previously demonstrated that parasite antigens integrated into a tricomponent immunopotentiating complex increase antiparasitic immunity. In this study, the B domains of a group G Streptococcus (SpG) strain and Peptostreptococcus magnus (PpL) were used to evaluate whether vaccine efficacy is influenced by the type of immunoglobulin-binding domain (IBD) in the tricomponent complex. IBDs were fused to a pentameric cartilage oligomeric matrix protein (COMP) to increase the binding avidity of the complexes for their targets. The COMP-IBD fusion proteins generated (COMP-SpG and COMP-PpL and the previously constructed COMP-Z) bound a large fraction of splenic B lymphocytes but not T lymphocytes. These carrier molecules were then loaded with an ookinete surface protein of Plasmodium vivax, Pvs25, by chemical conjugation. The administration of the tricomponent complexes to mice induced more Pvs25-specific serum IgG than did the unloaded antigen. The PpL complex, which exhibited a broad Ig-binding spectrum, conferred higher vaccine efficacy than did the Z or SpG complexes when evaluated with a membrane feed assay. This study demonstrates that this tricomponent immunopotentiating system, incorporating IBDs as the B-lymphocyte-targeting ligands, is a promising technology for the delivery of malaria vaccines, particularly when combined with an aluminum salt adjuvant. Copyright © 2014 American Society for Microbiology. All Rights Reserved.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyImmunology and MicrobiologyMedicineArticleSCOPUS10.1128/CVI.00053-14