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
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).