HSV-1 induces cell death in the SIRC cell line. SIRC cells were infected with HSV-1 at different MOIs for 48 h. Mock-infected cells cultured in parallel were left untreated. The cell viability was measured by using the MTT assay (A). Apoptosis was detected by measuring the specific enrichment of mono- and oligonucleosomes in the cytoplasm by ELISA (B). The enrichment factor was calculated as the absorbance of HSV-1-infected cells/absorbance of corresponding non-infected control cells. Data are mean (± SD) values from four independent experiments. P values were calculated by the ANOVA test with the Bonferroni post-test. aP < 0.001 vs. mock; bP < 0.001 vs. 0.1 MOI; cP < 0.001 vs. 1 MOI; ns = nonsignificant vs. mock.