CD4 and autoimmune hepatitis: In mouse models of AIH (Ad-hFTCD-infected NOD mice) (102) it has been demonstrated that engineered peptide-MHC complex-coated nanoparticles loaded with relevant AIH specific peptides activated and expanded cognate CD4+ type 1 regulatory (Tr1) T cells and regulatory B cells, and reduced liver inflammation, fibrosis, and alanine aminotransferase (ALT) levels without compromise immunity against viruses (vaccinia, influenza), intracellular bacteria (Listeria), or metastatic (liver) allogeneic tumors (102–104).