Fig. (1) PGE2 production in mixed cultures of DO11.10 CD4+ T cells, B cells, and elicited peritoneal macrophages infected with Salmonella typhimurium. Peritoneal macrophages were isolated and cultured in the presence of medium alone (A) or viable Salmonella(B). The dose of bacteria initially added to each well was 3:1 (3) or 10:1 (10) bacteria to macrophage, as indicated. Following exposure for 45 minutes, cells were washed to remove any extracellular bacteria with gentamicin-containing medium. Magnetically separated splenic DO11.10 CD4 + T cells, B cells, and OVA peptide were added. Some cultures were supplemented with 1 uM celecoxib 20 minutes prior to infection. Culture supernatants were collected at 24 hours post-infection and stored at -80°C. Levels of PGE2 were measured by enzyme immunoassay, and are reported as mean values of triplicate determinations. An asterisk indicates a statistically significant difference (p < 0.01) when compared to cultures without celecoxib. These studies were performed three times with similar results.