Fig 1. HPV16 evades cGAS/STING responses in HaCaTs during initial infection.

cGAS/STING responses to pGL3 and HPV PsV in HaCaTs. (A, B) Cells were either transfected for 90 min with 250 ng pGL3 or infected for the duration of the experiment with 950 ng L1 (equivalent to 250 ng DNA) of HPV16 virions. Cells were harvested at various times post-treatment and cGAS/STING responses assessed via western blotting. (A) IRF3 was phosphorylated, most prominently at 90 min and 4 hr post pGL3 transfection, while IRF3 was not phosphorylated at any time post HPV16 infection, representative blot of n = 4 biological replicates. (B) Densitometric quantification of western blots, n = 4 biological replicates. Statistics calculated by two-way ANOVA (P_interaction = 0.0138) followed by Sidak’s multiple comparison test (***P < 0.005). (C) Cells were either transfected for 90 min with 250 ng pGL3 or infected for the duration of the experiment with an equivalent amount of HPV virions. Luciferase activity was measured 24 hr post-treatment, normalized to GAPDH, and corrected for pGL3 encapsidation as described in Materials and Methods. Differences were not significant (n.s.) by unpaired t-test, n = 3 biological replicates.