(J, K) THP-1 cells stably expressing full-length nucleocapsid or truncated nucleocapsid lacking amino acids 70-160 and 290-360 were stimulated with 10 μM nigericin for 30 min following pretreatment with 1 μg/ml LPS for 3 h. An ELISA assay was performed to determine supernatant IL-1β levels (J) and a cell viability assay was conducted to verify the percentage of viable cells through checking cellular ATP levels (K). For J, K, Control vector used here was empty vector corresponded to the nucleocapsid-containing vector. For J, K, Student's t-test was used and data were shown as means±SD of three technical replicates. *, P<0.05. Results were repeated for three times with similar results. 