Characterization of Hela cells for presentation of exogenous antigens

243-249Role of MHC class I HLA A2 HC and trimeric molecules on the binding of exogenous HBV core antigen was studied in Hela cells transfected with MHC class 1 HLA A2. HC and trimeric HLA A2 molecules could be identified with specific monoclonal antibodies. HC and trimeric HLA-A2 molecules exist in varying proportion on the cell surface of Hela cells. MHC class I HC molecules on the cell surface do not bind HBV core peptide. The exchange of peptide with MHC class 1 molecules on the cell surface is inefficient with cells exhibiting a maximal binding (12%) at 1.5μM of peptide. Hence, presentation of exogenous HBV core antigen molecules occurs after endocytosis of the antigen and MHC class 1 molecules, followed by functional trimer complex formation in endolysosomal compartments