Enhancing Dendritic Cell Migration and Inducing Efficient In-vivo Immune-modulation by Combinatorial, Single Formulation Delivery of siRNA, DNA Vaccine and Chemokines

摘要

RNA interference mediated gene knockdown is a potential immuno-modulatory tool for tuning dendritic cells (DC) activation and function in-vivo. We recently developed a gene carrier system capable of simultaneously delivering siRNA and DNA to same cell. Our results demonstrate that co-delivery of Interleukin-10 specific short-interfering RNAs (siRNA) along with DNA antigens to the same DC would inhibit IL-10 production, enhance DC activation, antigen presentation, and T cell response. Non-toxic, polyethyleneimine (PEI)- functionalized, poly(lactic-co-glycolic acid) (PEI-PLGA) microparticles co-delivering IL-10 siRNA and DNA antigen exhibited significantly higher (p<0.05) IL-10 gene knockdown in primary DCs and DNA transfection invitro. In murine model of Hepatitis B surface antigen (HBsAg), mice immunized intramuscularly with (IL-10)- siRNA-HBsAg-PEI-PLGA particles demonstrated successful “switch” towards a stronger Th1 response as compared to naked DNA or HBsAg loaded PEI-PLGA treated animals. We hypothesize that it is critical for an immunotherapeutic system for infectious, parasitic or cancer diseases to not only “drive” the antigen (Ag) specific immune response strongly towards either T helper type 1 (Th1) or Th2 phenotype, but also promote recruitment of high number of APCs at the immunization site. We present here a novel multi-tiered delivery system for combinatorial administration of chemokines (to attract DCs), siRNA, and plasmid DNA antigens in a single injectable carrier system.