Stabilization of TNF-α mRNA by S. pneumoniae is dependent on the viability of the bacteria. RAW-TNF-AU+ and RAW-TNF-AU÷ cells were seeded and treated with vehicle, live pneumoniae (5 × 107 bacteria/ml), or LPS (100 ng/ml) as well as bacteria (5 × 107 bacteria/ml) killed by either (A), heat, UV, or (B) penicillin treatment. Total cell lysates were harvested 20 h later and CAT was measured by ELISA. The data is shown as means +/- SEM. Similar results were obtained in 2–3 independent experiments.