FIG 4.

Progesterone pretreatment is required for enhanced HEV replication in human liver cells. (A) Experimental regimen of progesterone pretreatment (80 nM PRO Pre) and posttreatment (80 nM PRO Post). (B) HEV infectious titer. (C) HEV negative-strand RNA copy numbers. (D) Fold change (in percentage) in HEV-P6 transfected Huh7-S10-3 cells during pre- or posttreatment with progesterone. Data represent an average ± SEM from panels B (n = 3) and C and D (n = 7 independent experiments). Statistical analyses were performed with Student’s t test (panel B), one-way ANOVA with post hoc Tukey’s test (panel C), and the Friedman test (panel D) of differences among the multiple groups, which rendered a chi-square value of 7.71, which was significant (P = 0.02). *, P ≤ 0.05; **, P ≤ 0.01 compared to HEV-P6 by Student’s t test. 80 nM PRO = 25 ng/ml progesterone final concentration.