Figure 3

Apoptosis in HGF cells by P. gingivalis infection. Infection of HGF monolayers and staining for all nuclei (DAPI, Blue) or only the apoptotic ones (TUNEL, Green) were carried out as described under Experimental Procedures. Cells were infected by wild type (WT) or the triple gingipain mutant (MT), and stained at the indicated time of infection (5 h, 24 h, 48 h). For positive control of apoptosis, uninfected HGF cells were treated with staurosporine for 5 h.