PCPP (poly[di(carboxylatophenoxy)-phosphazene]) microparticles co-encapsulating ovalbumin and CpG oligo-deoxynucleotides are potent enhancers of antigen specific Th1 immune responses in mice

• Published in: Vaccine 2010-12, Vol.28 (52), p.8306-8314
• Main Authors: Garlapati, Srinivas, Eng, Nelson F, Wilson, Heather L, Buchanan, Rachelle, Mutwiri, George K, Babiuk, Lorne A, Gerdts, Volker
• Format: Article
• Language: English
• Subjects: Adjuvants, Immunologic - administration & dosage; Allergy and Immunology; Animals; Applied microbiology; Biological and medical sciences; CpG; Drug Carriers; Efficiency; Fundamental and applied biological sciences. Psychology; Immune response; Immune system; Immunoglobulin G - blood; Injections, Subcutaneous; Lymph nodes; Lymph Nodes - immunology; Medical research; Mice; Mice, Inbred BALB C; Microbiology; Microparticles; Microspheres; Nanoparticles; Oligodeoxyribonucleotides - administration & dosage; Organophosphorus Compounds - administration & dosage; Ovalbumin - immunology; Polymers - administration & dosage; Polyphosphazene; Proteins; Studies; Th1 Cells - immunology; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); Whole Body Imaging - methods
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2010.09.080

Abstract We generated poly[di(carboxylatophenoxy)-phosphazene] (PCPP) microparticles encapsulating ovalbumin (OVA) and CpG of 0.5–2.5 μm in diameter with an encapsulation efficiency of approximately 63% and 95% respectively. In mice the microparticles generated high antigen-specific IgG, IgG1 and IgG2a titers with higher IgG2a/IgG1 ratios. Whole body in vivo imaging of mice subcutaneously injected with MPs showed several fold increase of OVA and CpG in draining inguinal lymph nodes compared to soluble formulations. We conclude that PCPP MPs are more effective in enhancing immune responses compared to soluble formulations, due to co-delivery of OVA and CpG resulting in a Th1 type of immune response.