title: Encapsulation of chimeric protein rSAG1/2 into poly(lactide-co-glycolide) microparticles induces long-term protective immunity against Toxoplasma gondii in mice.
abstract: In the present study, the poly(lactide-co-glycolide) (PLG) polymer was used as an adjuvant to encapsulate the chimeric protein rSAG1/2 for preparing a microparticle vaccine against Toxoplasma gondii. The resulting PLG-encapsulated rSAG1/2 (PLG-rSAG1/2) microparticles, 1.27-1.65μm in diameter, showed 72-83% entrapment efficiency. The amount of released rSAG1/2 protein from microparticles gradually increased over a long 56-day period and the protein still retained its antigenicity. Intraperitoneal immunization with the microparticles in BALB/c mice elicited significant long-term (10weeks) humoral and cell-mediated immune responses, accompanied by secretion of a large amount of IFN-γ, to achieve strong protection (83%) against a lethal subcutaneous tachyzoite challenge. In conclusion, we have successfully encapsulated rSAG1/2 with the PLG polymer to produce stable microparticles that can effectively induce not only long-term immunity but also high protection against T. gondii. These crucial data would be advantageous for developing long-term Toxoplasma vaccines for future use in humans and animals.
authors.affiliation: Department of Physiology, College of Medicine, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.
authors.forename: Shu-Chun
authors.initials: SC
authors.lastname: Chuang
authors.forename: Jing-Chun
authors.initials: JC
authors.lastname: Ko
authors.forename: Chaio-Ping
authors.initials: CP
authors.lastname: Chen
authors.forename: Jia-Tze
authors.initials: JT
authors.lastname: Du
authors.forename: Chung-Da
authors.initials: CD
authors.lastname: Yang
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000097:blood; D000953:Antigens, Protozoan / Q000008:administration & dosage / Q000276:immunology*; D001672:Biocompatible Materials; D002214:Capsules; D003692:Delayed-Action Preparations; D007106:Immune Sera / Q000276:immunology; D007111:Immunity, Cellular; D007114:Immunization; D007371:Interferon-gamma; D019344:Lactic Acid; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D015800:Protozoan Proteins / Q000008:administration & dosage / Q000276:immunology*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000276:immunology*; D014122:Toxoplasma / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000517:prevention & control*
chemical_list: D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D001672:Biocompatible Materials; D002214:Capsules; D003692:Delayed-Action Preparations; D007106:Immune Sera; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; C047168:SAG1 antigen, Toxoplasma; C067547:surface antigen P22, Toxoplasma; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D007371:Interferon-gamma
keywords: Long-term immunity; PLG-rSAG1/2 microparticles; Poly(lactide-co-glycolide) (PLG); Toxoplasma gondii (T. gondii); rSAG1/2