The effect of chitosan-tripolyphosphate nanoparticles on maturation and function of dendritic cells

Abstract

Nanoparticles can decrease the defects of usual drug and gene delivery systems. Chitosan is a low-toxicity, biodegradable, biocompatible, and safe polymer which is used in the production of nanoparticles. Nanoparticles including chitosan-tripolyphosphate (TPP) can affect the immune cells including dendritic cells (DCs) as the most potent antigen-presenting cells with a pivotal role in both humoral and cellular immunity. For efficient antigen presentation, DCs need to become mature and express high levels of class II major histocompatibility complex (MHC-II) as well as costimulatory molecules, including CD40 and CD86 molecules. In this study, we investigated the effects of chitosan-TPP nanoparticles on DC maturation and function. Chitosan-TPP was synthesized by ionotropic gelation methods from chitosan and TPP salt, and DCs were isolated from mouse spleen using the magnetic cell separation method. DCs were treated with chitosan-TPP nanoparticles during an overnight cell culture and phenotypic and functional characteristics of chitosan-TPP-treated DCs were evaluated by flow cytometric analysis. Our results showed that chitosan-TPP induced DC maturation. Moreover, chitosan-TPP-treated DCs were shown to be efficient inducers of T cell proliferation in allogenic mixed lymphocyte reaction. Indeed, chitosan-TPP as an adjuvant is able to induce DC maturation which is a vital step in efficient antigen presentation and activation of the immune system. Thus, chitosan-TPP nanoparticles can be used as a dual-function agent in clinical immunotherapy methods aiming at using them in drug and gene delivery as well as in potentiating immune responses.