Liposome-based intranasal delivery of lipopeptide vaccine candidates against group A streptococcus

Abstract

Group A streptococcus, causing rheumatic heart diseases, kills approximately half a million people annually. There is no vaccine available against the infection. Mucosal immunity is vital in ensuring an individual is protected as this gram positive bacteria initially colonizes at the throat. Herein, we demonstrated that lipopeptides entrapped by liposomes induced both mucosal and systemic immunity. High levels of antibody (IgA and IgG) titres were detected even five months post immunization and lead vaccine candidate was able to induce humoral immune responses even after single immunization. Thus, the combination of lipopeptides and liposomes generates a very promising delivery system for intranasal vaccines.

Polyglutamic acid-trimethyl chitosan-based intranasal peptide nano-vaccine induces potent immune responses against group A streptococcus

“…An indirect bactericidal assay indicated that serum antibodies produced in mice immunized with NP-1 were effective not only against the M1 GAS strain, but also against a variety of clinical isolates ( Figure 5D). Overall, NP-1, even at low antigen concentration compared to previous reports [30,[51][52][53], induced high IgA and opsonic IgG antibody titers and showed protection against GAS infection.…”

“…To determine J8-specific IgG and IgA antibody titers, enzyme-linked immunosorbent assays (ELISA) were performed [30]. Flat bottom 96-well plates were coated with J8 peptide (5 µg/well) and blocked with 5% skim milk.…”

Novel platform technology for modular mucosal vaccine that protects against streptococcus

“…Previous liposomal research involved vaccine construction using cationic liposomes with peptide antigens and the use of linked ‘universal’ T-cell epitope peptides to induce T-cell help3435. These are useful approaches but lack the utility of the Peptide-Lipo-DT approach where additional B-cell peptide epitopes can be readily displayed on the liposomal surface and do not require chemical conjugation to a T-cell peptide epitope.…”

Liposomal formulation of polyacrylate-peptide conjugate as a new vaccine candidate against cervical cancer

“…A similar effect was observed when lipids were used to anchor peptides to liposomes. 24,25 Taken together, the physicochemical properties of liposomes 8Qm-L and 8Qm-D-L were only slightly different.…”

“…Importantly, the combination of a liposomal delivery system with the conjugation strategy improved immune response in a synergistic manner. 24 Here we examined whether this strategy can also be applied to polymer-based conjugates designed to induce cellular immune responses. Thus, C57Bl/6 female mice were inoculated subcutaneously in the flank with 2 x10 5 TC-1 cells/mouse on day 0, then mice were immunized with 8Qm-D, 8Qm-L, 8Qm-D-L, and controls (PBS, 8Qm + IFA) on day 7.…”