mAb reactivity of deglycosylated SOSIP.664GnTl−/− trimers. The trimers were either Endo H-treated or mock-treated, and then immunoprecipitated with various mAbs (left lanes, no mAb controls). The precipitated trimers were analyzed by SDS-PAGE and Western blotted using the anti-gp120 antibody ARP3119. A, gp120-binding agents b12, CD4-IgG2, 17b ± sCD4, 2G12, and DC-SIGN; and anti-gp41 MAbs 2F5 and 4E10; B, V3 mAbs 447–52D, 5.8c and 1.4e; and CD4-IgG2 and PGT123. The right panels represent loading controls for the immunoprecipitation reactions in A and B.