Figure 1.

Characterizations of PMA stimulated and native THP-1 cells. (A) THP-1 cells, PMA stimulated or native, exposed to different concentrations of A. actinomycetemcomitans LtxA for 2 h. Leukotoxicity is expressed as the activity of LDH released from the damaged cells (cell lysis) compared to that of triton-lysed control cells (100%, not shown) (mean ± SD, n = 3 for with PMA and 5 for without PMA, ** p ≤ 0.01, *** p ≤ 0.001). (B) Expression of LFA-1, pro-caspase-1 and connexin 43 (Cx43) in native THP-1 cells. Right peaks represent fluorescence from cells labeled with the specific conjugated antibodies, and left peaks represent cells labeled with the corresponding conjugated isotype control. Representative results are shown.