Virus isolates during acute and chronic human immunodeficiency virus type 1 infection show distinct patterns of sensitivity to entry inhibitors

Abstract

We studied the effect of entry inhibitors on 58 virus isolates derived during acute and chronic infection to validate these inhibitors in vitro and to probe whether viruses at early and chronic disease stages exhibit general differences in the interaction with entry receptors. We included members of all types of inhibitors currently identified: (i) agents that block gp120 binding to CD4 (CD4-IgG2 and monoclonal antibody [MAb] IgG1b12), (ii) compounds that block the interaction with CCR5 (the chemokine RANTES/CCL5, the small-molecule inhibitor AD101, and the anti-CCR5 antibody PRO 140), (iii) the fusion inhibitor enfuvirtide (T-20), and (iv) neutralizing antibodies directed against gp120 (MAb 2G12) and gp41 (MAbs 2F5 and 4E10). No differences between viruses from acute and chronic infections in the susceptibility to inhibitors targeting the CD4 binding site, CCR5, or fusion or to MAb 2G12 were apparent, rendering treatment with entry inhibitors feasible across disease stages. The notable exceptions were antibodies 2F5 and 4E10, which were more potent in inhibiting viruses from acute infection (P = 0.0088 and 0.0005, respectively), although epitopes of these MAbs were equally well preserved in both groups. Activities of these MAbs correlated significantly with each other, suggesting that common features of the viral envelope modulate their potencies.

Figures

FIG. 1.

Antibody titers to Env and Gag. (a and b) Binding antibody titers to (a) Env (gp120) and (b) Gag (p24) in the acute and chronic patient groups. Means from two independent experiments are shown. A value of

FIG. 2.

CD4 binding site inhibitors. (a) Antibody titers in acute and chronic patient groups directed against the CD4BS. Means from two independent experiments are shown. A value of 2 and IgG1b12 in acutely and chronically infected individuals. Means from two independent experiments are shown. Groups were compared using the Mann-Whitney test. Open and closed circles indicate acutely infected and chronically infected individuals, respectively. Horizontal lines indicate median values. P values for subtype B viruses only: CD4-IgG2, P = 0.71; IgG1b12, P = 0.60. (d) Correlation analysis of sensitivities to CD4-IgG2 and IgG1b12. (e and f) Correlation analysis of anti-CD4BS responses in autologous sera and sensitivities to CD4-IgG2 and IgG1b12, respectively. Significance was evaluated after Bonferroni correction. The solid lines are the regression lines, and the dashed lines indicate 95% confidence intervals.

FIG. 3.

CCR5 inhibitors. (a to c) Ninety percent inhibitory doses of RANTES, PRO 140, and AD101 in acutely and chronically infected individuals. Means from two independent experiments are shown. Groups were compared using the Mann-Whitney test. Open and closed circles indicate acutely infected and chronically infected individuals, respectively. Horizontal lines indicate median values. P values for subtype B viruses only: RANTES, P = 0.74; PRO 140, P = 0.88; AD101, P = 0.99. (d to f) Correlation analysis of sensitivities to RANTES, PRO 140, and AD101. Significance was evaluated after Bonferroni correction. The solid lines indicate the regression lines, and the dashed lines indicate 95% confidence intervals. R5X4 viruses were excluded from the analysis of CCR5 inhibitors.

FIG. 4.

Interdependencies between CD4BS and CCR5 inhibitors. (a to c) Correlation analysis of 70% inhibitory doses of CD4-IgG2 and 70% inhibitory doses of RANTES, PRO 140, and AD101, respectively. (d to f) Correlation analysis of 70% inhibitory doses of IgG1b12 and 70% inhibitory doses of RANTES, PRO 140, and AD101, respectively. Significance was evaluated after Bonferroni correction. The solid lines indicate the regression lines, and the dashed lines indicate 95% confidence intervals. R5X4 viruses were excluded from the analysis of CCR5 inhibitors.

FIG. 5.

Sensitivity to the fusion inhibitor T-20. (a) Ninety percent inhibitory doses of T-20 in acutely and chronically infected individuals. Means from two independent experiments are shown. Groups were compared using the Mann-Whitney test. Open and closed circles indicate acutely infected and chronically infected individuals, respectively. Horizontal lines indicate median values. For subtype B viruses only, P = 0.62. (b and c) Correlation analysis of 70% inhibitory doses of T-20 and sensitivities to CD4-IgG2 and IgG1b12, respectively. (d to f) Correlation analysis of 70% inhibitory doses of T-20 and sensitivities to RANTES, PRO 140, and AD101, respectively. Significance was evaluated after Bonferroni correction. R5X4 viruses were excluded from the analysis of CCR5 inhibitors. The solid lines indicate the regression lines, and the dashed lines indicate 95% confidence intervals.

FIG. 6.

Sensitivity to the neutralizing antibodies 2G12, 2F5, and 4E10. (a to c) Ninety percent inhibitory doses of 2G12, 2F5, and 4E10 in acutely and chronically infected individuals, respectively. Means from two to five independent experiments are shown. Groups were compared using the Mann-Whitney test. Open and closed circles indicate acutely infected and chronically infected individuals, respectively. Horizontal lines indicate median values. P values for subtype B viruses only: 2G12, P = 0.61; 2F5, P = 0.057; 4E10, P = 0.012. (d) Correlation analysis of 70% inhibitory doses of 2F5 and 4E10. Significance was evaluated after Bonferroni correction. The solid line indicates the regression line, and the dashed lines indicate 95% confidence intervals.

FIG. 7.

Sequence analysis of 2F5 and 4E10 epitopes. The gp41 sequences of patient isolates are presented in comparison to that of the reference strain LAI. Core positions of the 2F5 and 4E10 epitopes are shaded. IC90, 90% inhibitory dose in μg/ml.