Thus, the data in the present study demonstrated that antigens coupled to oleoyl liposomes were internalized by APCs through both penetration and pinocytosis. The antigens coupled to the surface of oleoyl liposomes were processed at both MHC class I and class II compartments and presented to CD4 + -and CD8 + T cells. Although the detailed pathway leading to presentation to both CD4 + -and CD8 + T cells remains unclear, the observed behavior of antigens coupled to oleoyl liposome in APCs seems quite unique. Taken together, coupling of antigens to oleoyl liposome might potentially serve as a novel method to induce both humoral and cellular immunity.