Evaluation of human cytokine production and effects of pharmacological agents in a heterologous system in vivo

The ability of human monocytes adoptively transferred into the peritoneal cavity of BALBc mice to produce tumor necrosis factor-α (TNF) and interleukin 1β (IL-1) was studied. Human monocytes were isolated from fresh, heparinized blood obtained by venipuncture. BALBc mice were administered 2–10 × 106 cells and challenged with lipopolysaccharide intraperitoneally. 2 h later, they were killed and a peritoneal washout was obtained. The washouts were assayed for TNF and, in some cases, IL-1 content using a species specific enzyme-linked immunosorbant assay (ELISA). This model allowed for the simultaneous evaluation of the production of mouse and human inflammatory cytokines. Significant levels of both human and mouse TNF were seen as early as 60 min after challenge. Peak levels for both were seen at 120 min post administration of LPS. Both human and mouse TNF concentrations declined at the 2 h time point. The phosphodiesterase type 4 inhibitor, R-rolipram was found to inhibit both human and mouse TNF production while SB CSAID, novel kinase inhibitor SB 203580 inhibited human IL-1 and TNF as well as mouse TNF. This model was reliable, reproducible and allowed evaluation of pharmacological agents for their effect on human cytokine production in a heterologous setting in vivo.