The present invention relates to nanoparticles for the targeted delivery of antigen to liver cells, in particular, liver sinusoidal endothelial cells (LSEC) and/or Kupffer cells, and for the in vivo generation of regulatory T cells, notably CD4+CD25+FOXP3+ regulatory T cells (Treg). The invention provides pharmaceutical compositions and methods for the prevention and treatment of autoimmune diseases, allergies or other chronic inflammatory conditions, and for generation of regulatory T cells. The nanoparticles used in the invention comprise a) a micelle comprising an amphiphilic polymer rendering the nanoparticle water-soluble, and b) a peptide comprising at least one T cell epitope associated with the outside of the micelle. The micelle may or may not comprise a solid hydrophobic core.
