Plasmacytoid dendritic cells of melanoma patients present exogenous proteins to CD4+ T cells after Fc gamma RII-mediated uptake.

ABSTRACT: Plasmacytoid dendritic cells (pDCs) contribute to innate antiviral immune responses by producing type I interferons. Although human pDCs can induce T cell responses upon viral infection, it remains unclear if pDCs can present exogenous antigens. Here, we show that human pDCs exploit FcgammaRII (CD32) to internalize antigen-antibody complexes, resulting in the presentation of exogenous antigen to T cells. pDCs isolated from melanoma patients vaccinated with autologous monocyte-derived peptide- and keyhold limpet hemocyanin (KLH)-loaded dendritic cells, but not from nonvaccinated patients or patients that lack a humoral response against KLH, were able to stimulate KLH-specific T cell proliferation. Interestingly, we observed that internalization of KLH by pDCs depended on the presence of ser

SUBMITTER: Benitez-Ribas D 

PROVIDER: S-EPMC2118356 | biostudies-literature | 2006 Jul

REPOSITORIES: biostudies-literature