Background
The conserved membrane-proximal external region (MPER) of HIV-1 envelope is a target for the rare broadly neutralizing 2F5, Z13 and 4E10 monoclonal antibodies (mAbs). However, MPER antibodies are rarely found in HIV-1 infected subjects nor arise following envelope immunization. A potential strategy to elicit such antibodies more frequently is to design an envelope protein with increased exposure of the 2F5 and 4E10 mAb epitopes.