TY - JOUR IS - 2 AV - public A1 - Strokappe, NM A1 - Hock, M A1 - Rutten, L A1 - Mccoy, LE A1 - Back, JW A1 - Caillat, C A1 - Haffke, M A1 - Weiss, RA A1 - Weissenhorn, W A1 - Verrips, T SN - 2073-4468 KW - Aids KW - HIV KW - Llama Antibodies KW - bi-specific VHH KW - co-crystallisation KW - competition studies KW - epitope mapping KW - pepscan N2 - Broad and potent neutralizing llama single domain antibodies (VHH) against HIV-1 targeting the CD4 binding site (CD4bs) have previously been isolated upon llama immunization. Here we describe the epitopes of three additional VHH groups selected from phage libraries. The 2E7 group binds to a new linear epitope in the first heptad repeat of gp41 that is only exposed in the fusion-intermediate conformation. The 1B5 group competes with co-receptor binding and the 1F10 group interacts with the crown of the gp120 V3 loop, occluded in native Env. We present biophysical and structural details on the 2E7 interaction with gp41. In order to further increase breadth and potency, we constructed bi-specific VHH. The combination of CD4bs VHH (J3/3E3) with 2E7 group VHH enhanced strain-specific neutralization with potencies up to 1400-fold higher than the mixture of the individual VHHs. Thus, these new bivalent VHH are potent new tools to develop therapeutic approaches or microbicide intervention. JF - Antibodies VL - 8 ID - discovery10082648 Y1 - 2019/06// UR - https://doi.org/10.3390/antib8020038 TI - Super Potent Bispecific Llama VHH Antibodies Neutralize HIV via a Combination of gp41 and gp120 Epitopes N1 - © 2019 by the Authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). ER -