ABSTRACT
BACKGROUND: Group A streptococcus (GAS) is an exclusively human pathogenic bacteria. A delay in treatment of GAS infection often lead to severe diseases such as rheumatic heart disease which attributes to hundreds of thousands deaths annually. For the past few decades, the quest for a commercial GAS vaccine has been futile. Currently one of the most investigated strategies to develop vaccine against GAS includes the use of conserved epitopes from major virulent factor of GAS, M-protein. METHODS: In this study, cationic liposomes of various sizes (70 nm to 1000 nm) were prepared with dimethyldioctadecylammonium bromide (DDAB) encapsulating lipopeptide bearing M-protein derived B-cell epitope (J14). RESULTS: Smaller liposomes induced higher antibody titres, though the differences between groups were not statistically significant. CONCLUSION: Nonetheless, all mice which were immunized with liposome-lipopeptide delivery system elicited high levels of systemic (IgG) and mucosal antibodies (IgA), which were discernably higher than those induced with the help of commercial adjuvant (cholera toxin B subunit).
Subject(s)
Immunity, Mucosal/immunology , Lipopeptides/immunology , Liposomes/immunology , Streptococcal Infections/therapy , Streptococcal Vaccines/immunology , Streptococcus pyogenes/drug effects , Animals , Dose-Response Relationship, Drug , Female , Mice , Molecular Structure , Streptococcal Infections/immunology , Streptococcus pyogenes/immunology , Structure-Activity RelationshipABSTRACT
AIM: To develop an oral nanovaccine delivery system for lipopeptide-based vaccine candidate against group A Streptococcus. MATERIALS & METHODS: Lipid-core peptide-1-loaded nanoliposomes were prepared as a template and coated with opposite-charged polyelectrolytes to produce particles with size <200 nm. Efficacy of this oral nanovaccine delivery system was evaluated in mice model. RESULTS: Polymer-coated liposomes produced significantly higher antigen-specific mucosal IgA and systemic IgG titers in comparison to vaccine formulated with a strong mucosal adjuvant upon oral immunization in mice. Moreover, high levels of systemic antibody titers were retained even at day 185 postprimary immunization. CONCLUSION: Efficient oral delivery platform for lipopeptide-based vaccines has been developed.
