Comparative immunogenicity analysis of modified vaccinia Ankara vectors expressing native or modified forms of hepatitis C virus E1 and E2 glycoproteins

We have evaluated in C57[1316 and HLA-A2.1 transgenic mice the immunogenicity of three MVA vectors expressing either native HCV El E2 polyprotein. truncated and secreted El (E'1 (311)) and E2 (E'2(661)) proteins, or a chimeric El E2 heterodimer presented at the plasma membrane. Immunization induced mainly a Th1 response in HLA-A2.1 transgenic mice while a Th2-type response was detected in C57/B16 mice. Comparison of the three vectors shows an increase in the humoral response when antigens are secreted or membrane bound, and slightly in the cellular response when antigens are exposed on the cell surface. (C) 2004 Elsevier Ltd. All rights reserved.