Fig. 1: Incompletely closed Env conformation of transmitted/founder (T/F) strains.
a We measured the sensitivity of WT and 53 selected HIV-1JRFL Env variants, which are enriched (not randomly selected) in intermediates, to ligands that recognize internal Env epitopes (sCD4; 17b, 19b, 902 antibodies; and T20 peptide) and calculated the contribution of each HIV-1 Env site exposure to trimer opening (number of variants hypersensitive to the specified antibodies; Supplementary Table 1 and Supplementary Fig. 1). Sensitivity of CH040 (b), SC45 (c), and WEAU (d) Envs to different antibodies recognizing internal epitopes. BG505 Envs were used as a control in (b). Data in (b–d) are mean values ± s.d.; n = 3 independent experiments each performed with 2–4 replicates (b, right), data are representatives of n = 3 (b, left) or 2 (c, d) independent experiments each performed with 2–4 replicates. Data in (b left) and (b right) are 2 independent sets of experiments. e Relationship between T/F Env sensitivity to internal-epitope antibodies and the sensitivity to cold. t1/2 values higher than the maximal time tested (96 h) were set to an arbitrary value of 100 h. Relationship between cold and sCD4 sensitivities of T/F Envs that are sensitive (red) or resistant (blue) to internal-epitope antibodies. Dashed line is a log/log fit curve. rS, Spearman correlation coefficient; Strain IDs in (e, f) are identical and specified in the symbol code on the right. P, two-tailed Student’s t test P value (b, e) or two-tailed P value for calculated Spearman correlation coefficient (f). Source data are provided as a Source Data file.
