Modulation of innate and adaptive immunity by biodegradable nanoparticles

Vaccine strategy needs efficient adjuvants to induce potent antigen-specific immune responses by targeting antigens to antigen presenting cells followed by their functional maturation. In this study, biodegradable poly(γ-glutamic acid) (γ-PGA) nanoparticles (NPs) were examined for their immunological activities in mice. Like lipopolysaccharide, γ-PGA NPs strongly activated spleen dendritic cells (DCs) and induced their cytokine production and costimulatory molecule expression through the nuclear factor-κB and mitogen-activated protein kinase signaling pathways. The immunization of mice with ovalbumin-carrying γ-PGA NPs could induce the antigen-specific and long-lived effector and central memory CD8+ T cells as well as antibody responses. Thus, γ-PGA NPs have great potential as an efficient antigen carrier and strong adjuvant to DCs.