Figure 1.

Haemophilus influenzae increases intercellular adhesion molecule (ICAM)-1 gene transcription. (A) Relative gene transcription rates were assessed using nuclear runoff assays with human tracheobronchial epithelial (hTBE) cells incubated in media without or with H. influenzae for the indicated durations. The positions of ³²P-labeled transcripts that hybridized with immobilized vector without cDNA or vector containing ICAM-1, α-actin, c-Rel, and Alu repeat sequence cDNAs are indicated by arrows. Results are representative of three experiments. (B) ICAM-1 gene promoter activity was assessed using reporter gene assays with hTBE that were transfected with a plasmid containing a luciferase gene driven by ICAM-1 gene sequence from −1294, −553, −294, −200, −192, or −134 to +7 and then incubated without or with H. influenzae for 18 hours. Values are expressed as mean fold induction in luciferase activity relative to uninfected cells ± S.D. (n = 4–7 experiments, each with duplicate samples), and a significant difference from levels with constructs driven by the ICAM-1 gene sequence from −1294 to +7 is indicated by an asterisk.