Fig. 2.

PCBP1 positively regulates DNA virus-triggered signaling. a PCBP1 potentiates cGAS-MITA-induced ISRE activation in a dose-dependent manner. HEK293 cells (1 × 10⁵) were transfected with the ISRE luciferase reporter (50 ng), expression plasmids for cGAS (50 ng), MITA (50 ng), and increased amounts of PCBP1 and incubated for 20 h before luciferase assays. The graph shows the means ± SEM, n = 3. b Effects of PCBP1 deficiency on the HSV-1-triggered transcription of downstream genes in the MLFs. PCBP1-deficient MLFs were generated by the CRISPR-Cas9 method. PCBP1-deficient and control MLFs (1 × 10⁶) were untreated or infected with HSV-1 (MOI = 1) for the indicated times before qPCR analysis. PCBP1 deficiency in the KO cells was confirmed by immunoblot analysis (right blots). The graph shows the means ± SEM, n = 3. **P < 0.01 (unpaired t-test). c Effects of PCBP1 deficiency on the transcription of downstream genes induced by SeV in the MLFs. PCBP1-deficient and control MLFs (1 × 10⁶) were untreated or infected with SeV for 6 h before the qPCR analysis. The graph shows the means ± SEM, n = 3. **P < 0.01 (unpaired t-test). d Effects of PCBP1 deficiency on the transcription of downstream genes induced by cytosolic DNA in MLFs. PCBP1-deficient and control MLFs (1 × 10⁶) were left untreated or transfected with the indicated DNA (1 μg) for 4 h before the qPCR analysis. The graph shows the mean ± SEM, n = 3. *P < 0.05, **P < 0.01 (unpaired t-test). e Effects of PCBP1 deficiency on the transcription of downstream genes induced by HSV-1 and cytosolic DNA in THP-1 cells. PCBP1-deficient THP-1 cells were generated by the CRISPR-Cas9 method. PCBP1-deficient and control THP-1 cells (1 × 10⁶) were left untreated, infected with HSV-1 (MOI = 1) for 6 h or transfected with HT-DNA (0.5 μg) for 4 h before qPCR analysis. PCBP1 deficiency in KO cells was confirmed by immunoblotting analysis (right blots). The graph shows the mean ± SEM, n = 3. **P < 0.01 (unpaired t-test). f Deficiency of PCBP1 has no effect on transcription of downstream genes induced by IFN-β in MLFs. PCBP1-deficient and control MLFs (1 × 10⁶) were left untreated or treated with IFN-β (100 ng/mL) for 4 h before the qPCR analysis. The graph shows the means ± SEM, n = 3. g Effects of PCBP1 deficiency on the replication of HSV-1 in the MLFs. PCBP1-deficient and control MLFs (1 × 10⁶) were infected with HSV-1-GFP (MOI = 0.1) for 30 h followed by microscopy imaging (left) and flow cytometry (right). The graph shows the means ± SEM, n = 3. **P < 0.01 (unpaired t-test)