Group A Streptococcus (GAS), a gram-positive human-exclusive pathogen, has been accountable for variety of invasive and non-invasive diseases which may later lead to life threating diseases like rheumatic fever and rheumatic heart diseases. GAS remains globally sensitive to penicillin, despite reports that penicillin has failed to eradicate GAS pharyngitis and tonsillitis. Although research has been ongoing since 1923, vaccines against GAS are not yet available that requires cell-mediated and mucosal immunity stimulation. Since traditional vaccines that use the whole GAS pathogen may trigger an autoimmune response, B-cell fragments from M-protein like J8 peptide epitope (QAEDKVKQSREAKKQVEKALKQLEDKVQ) and universal T-helper epitope PADRE (AKFVAAWTLKAAA) were synthesized to develop different peptide constructs.
The development of such peptide vaccines requires a strong immunostimulant (adjuvant) or delivery system to boost the vaccines’ immunogenicity as peptides are poor immunogens on their own. Considering the associated toxicity of currently available adjuvants that invariably invoke adverse reactions, allergic responses and inflammation, herein, our study focuses on a development of a potent polymer-based delivery system that is able to induce immune responses against the peptide epitope, without the use of any additional adjuvant.