Immune-potentiation of Pneumococcal Capsular Polysaccharide Antigen using Albumin Microparticles

Abstract

Microparticles (MPs) offer several advantages as unique vaccine delivery system, including the ease to manufacture, targeted delivery of antigen payload, sustained antigen release and possible role as an immuneadjuvant. In this study, we evaluated albumin matrix for pneumococcal (Pnc) serotype specific capsular polysaccharide (PS) antigen MPs. Microencapsulation of Pnc PS was successful with a product yield of >72%. The MP size, 1-5 μm, and negative zeta potential (-26.5 mV) were optimized to ensure effective-uptake and presentation of Pnc PS antigens to immune cells. In mice, ST 19F and 23F MPs exhibited >10-fold increase (P<0.01) in ST specific IgG response over PS in solution given with or without alum. Relatively higher immune response was observed for ST 6B MPs when compared to PS solution; however, ST6B PS solution along with alum resulted in an overall higher response when compared to ST6B MPs. Microencapsulation may offer a simple and effective mechanism for the immune-enhancement of poorly immunogenic antigens such as Pnc PS.

Design and Biological Assembly of Polyester Beads Displaying Pneumococcal Antigens as Particulate Vaccine

“…To evaluate the efficacy of the pneumococcal polysaccharide-protein conjugate vaccines, the total IgG antibody production, IgG functionality (OPA assay using homologous strain), immunological memory, and protection in challenge studies were measured. , In our study and similar to previous reports, immune response evaluation showed that 19F-PhaC beads promoted the production of specific and high IgG titers than the group immunized with alum . Interestingly, the nonconjugated mix of 19F CPS and PHB beads did not induce detectable IgG titer, which suggested that codelivery of antigens and PHB beads is required for induction of an immune response. , In addition, IgG titer were superior when mice were vaccinated with 19F-PhaC than with 19F-TT, which was used as a positive control (Figure B).…”

Characterization and Applications of Colloidal Systems as Versatile Drug Delivery Carriers for Parenteral Formulations

“…Inability of vaccine candidates to invoke suitable immune responses leads to failed vaccine development [ 40 ]. There is a necessity for the development of potent as well as safe adjuvants to deliver new generations of vaccines against infectious (e.g., pneumonia) and non-infectious (e.g., cancer) diseases [ 41 , 42 ]. The invention of Baker et al provides composition and methods to stimulate immune responses using nanoemulsion and an inactivated pathogen via mucosal delivery [ 43 ].…”