Quitadamo B, Peters PJ, Repik A, O'Connell O, Mou Z, Koch M, Somasundaran M, Brody R, Luzuriaga K, Wallace A, Wang S, Lu S, McCauley S, Luban J, Duenas-Decamp M, Gonzalez-Perez MP, Clapham PR. HIV-1 R5 Macrophage-Tropic Envelope Glycoprotein Trimers Bind CD4 with High Affinity, while the CD4 Binding Site on Non-macrophage-tropic, T-Tropic R5 Envelopes Is Occluded. J Virol. 2018 01 15; 92(2).