<p>(A) PBMCs were incubated with different concentrations of the Rac1 inhibitor NSC23766 for 30 min and subsequently infected with <i>C. pneumoniae</i> (MOI 3), or (C) cells were first infected with <i>C. pneumoniae</i> (MOI 3) and NSC23766 was added 2.5 h post-infection. After incubating 16 hrs production of IL-1β was quantified by ELISA. Total RNA was harvested for quantification of chlamydial 16s rRNA production (B, D) using real-time PCR as indicated in the Materials and Methods section. (E) THP-1 cells were transfected with control siRNA or siRNA specific for Rac1. After 48 h, cells were infected with <i>C. pneumoniae</i> (MOI 3) for 16 hrs and knock down of Rac1 was assessed by reverse transcription PCR. (F) HEp-2 reinfection assay in which siRNA-transfected THP-1 cells infected with <i>C. pneumoniae</i> (MOI 0.5; 72 h) were harvested and inoculated onto monolayers of HEp-2 cells. Infected cells were then stained for Chlamydia 48 h p.i. and clamydial inclusions were counted. Data shown are representative for at least three (A–D) or two (E, F) experiments performed in duplicates.</p
