STING agonists induce IFN responses in the vaginal epithelium faster and more efficiently than TLR agonists.

<p>(<b>A</b>) HaCaT cells were treated with imiquimod (1μg/ ml), ODN2216 (1μg/ ml), and 3’3’-cAIMP (100μg/ ml) for 24 h. Levels of ISG15 and viperin were determined in the cell lysate by Western blotting. (<b>B</b>) Mice were treated intravaginally with imiquimod or ODN1826 (25 μg per mouse) 12 h prior to infection with HSV2. Vaginal washes were collected 48 h p.i. and viral load was determined. n = 5 per group. (<b>C-D</b>) Mice were anesthetized for 30 min and imiquimod, ODN1826, or 3’3’-cAIMP was applied to the vagina. Tissues were isolated (<b>C</b>) 6 h or (<b>D</b>) 36 h after treatment. Paraffin sections of the vaginal tissues were stained for viperin (red). DAPI (blue) marks the nuclei and the dotted white lines mark basal membrane between the epithelium and stroma. White arrows highlight examples of viperin positive cells. L = lumen, E = epithelium, S = stroma. n = 4. One representative picture is shown for each staining. (<b>E-G</b>) RNA was isolated from vaginal tissue treated as indicated for 6 h, and levels of <i>Ifnb</i>, <i>Mx1</i>, and <i>Tnfa</i> mRNA were determined by RT-qPCR. n = 4–5. mRNA levels were normalized to <i>Gapdh</i> and shown as relative levels of expression compared to mock-treated mice. (<b>B, E-G</b>) Statistics, Kruskal-Wallis test with Dunn’s multiple comparisons test. * = p<0,05 compared to mock treated.