[Gd@C₈₂(OH)₂₂]_n nanoparticles induce dendritic cell maturation and activate Th1 immune responses

Dendritic cells play a pivotal role in host immune defense, such as elimination of foreign pathogen and inhibition of tumorigenesis. In this paper, we report that [Gd@C₈₂(OH)₂₂]_n could induce phenotypic maturation of dendritic cells by stimulating DC production of cytokines including IL-12p70, upregulating DC co-stimulatory (CD80, CD83, and CD86) and MHC (HLA-A,B,C and HLA-DR) molecules, and switching DCs from a CCL5-responsive to a CCL19-responsive phenotype. We found that [Gd@C ₈₂(OH)₂₂]_n can induce dendritic cells to become functionally mature as illustrated by their capacity to activate allogeneic T cells. Mice immunized with ovalbumin in the presence of [Gd@C ₈₂(OH)₂₂]_n exhibit enhanced ovalbumin-specific Th1-polarized immune response as evidenced by the predominantly increased production of IFN-, IL-1-, and IL-2. The [Gd@C₈₂(OH) ₂₂]_n nanoparticle is a potent activator of dendritic cells and Th1 immune responses. These new findings also provide a rational understanding of the potent anticancer activities of [Gd@C₈₂(OH) ₂₂]_n nanoparticles reported previously.