title: Sustained release of recombinant surface antigen 2 (rSAG2) from poly(lactide-co-glycolide) microparticles extends protective cell-mediated immunity againstToxoplasma gondiiin mice.
abstract: Current development efforts of subunit vaccines againstToxoplasma gondii, the aetiological agent of toxoplasmosis, have been focused mainly on tachyzoite surface antigens (SAGs) such as SAG2, due to their attachment roles in the process of host-cell invasion. In the present study, we aimed to produce poly(lactide-co-glycolide) (PLG) microparticles (MPs) containing recombinant SAG2 (rSAG2) to induce improved immunity againstT. gondii. The resulting PLG-encapsulated rSAG2 (PLG-rSAG2) MPs, 2·14-3·63μm in diameter, showed 74-80% entrapment efficiency and gradually released antigenic rSAG2 protein (88·3% of the total protein load) for a long 33-day period. Peritoneal immunization with PLG-rSAG2 MPs in BALB/c mice resulted in not only sustained (10 weeks) lymphocyte proliferation and IFN-γproduction but also an improved protective capacity (87%) against a lethal subcutaneous challenge of 1×104live tachyzoites ofT. gondii(RH strain). In conclusion, the sustained release of rSAG2 protein from PLG-rSAG2 MPs extends Th1 cell-mediated immunity (lymphocyte proliferation and IFN-γproduction) and induces improved protection againstT. gondiitachyzoite infection in mice.
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.affiliation: Graduate Institute of Animal Vaccine Technology, National Pingtung University of Science and Technology, No. 1, Shuefu Road, Neipu, Pingtung 912, Taiwan.
authors.forename: Chung-DA
authors.initials: CD
authors.lastname: Yang
keywords: PLG-encapsulated rSAG2 microparticles (PLG-rSAG2 MPs); Toxoplasma gondii (T. gondii); cell-mediated immunity; poly(lactide-co-glycolide) (PLG); recombinant SAG2 (rSAG2)