Figure 2.

Modulation of the expression of SOCS-3, IRF-1, EGFR, and STAT-3 proteins in HGEC infected with P. gingivalis and activated by LPS-Pg. (a) HGEC were infected for 2 h with P. gingivalis at a MOI of 100 and with heat-killed P. gingivalis (Ina). Uninfected cells served as control (C). (b) HGEC were activated 2 and 24 h by 1 µg/mL of purified LPS-Pg. Non-activated cells served as controls (C). In both experiments, cellular extracts were prepared and analyzed by immunoblotting with antibodies to SOCS-3, IRF-1, EGFR, and STAT-3. No detection was obtained using an antibody raised against EGF (not shown). An antibody to GAPDH was used as an internal control to verify equal loading of total proteins in all wells. Histograms indicated the relative protein expression level during infection and activation. Levels were determined by pixel intensity of a protein band normalized to the intensity of the internal control GAPDH within the same assay. Differences (*) between a given ratio and the one obtained with control cells were analyzed with Student’s t-test (p < 0.0005).