Alexa 488 -labeled OVA were coupled to liposomes and were added to the cultures of macrophages. As shown in Fig. 2 , OVA coupled to oleoyl liposomes were internalized by APCs more efficiently than those coupled to stearoyl liposomes at 37uC. Interestingly, OVA coupled to oleoyl liposomes but not stearoyl liposomes were internalized significantly by APCs even in a 4uC environment.