THE EFFECTS OF ANTIINFLAMMATORY AND ANTIALLERGIC DRUGS ON CYTOKINE RELEASE AFTER STIMULATION OF HUMAN WHOLE-BLOOD BY LIPOPOLYSACCHARIDE AND ZYMOSAN A

IL-1 beta, IL-8, IL-6 and TNF alpha, derived from infiltrating leukocytes, are important mediators of inflammation in arthritic and allergic diseases. Heparinized human whole blood was evaluated as a model to study the effects of various classes of antiinflammatory drugs on cytokine release/biosynthesis from leukocytes. Whole blood was stimulated with zymosan A (1.5 mg/ml) or LPS (5 mu g/ml) for 4 h to induce cytokine release. Dexamethasone was the most potent inhibitor of TNF alpha, IL-1 beta, IL-6 and IL-8 release from LPS stimulated blood leukocytes (IC(50)s Of 0.19, 0.11 mu M, 0.16 and 0.07 respectively). In LPS stimulated blood, SKF-86002, a 5-lipoxygenase/cytooxygenasae inhibitor, and rolipram, a PDE TV inhibitor, also inhibited the release of TNF alpha (IC(50)s Of 33 and 11 mu M, respectively), IL-1 beta (IC(50)s Of 11 and 30 mu M, respectively), IL-6 (IC(50)s Of 56 and > 30, respectively) and IL-8 (IC(50)s Of 6.7 and 15, respectively), whereas isoproterenol (1 mu M) inhibited significantly only TNF alpha release. Nonsteroidal antiinflammatory drugs, 5-lipoxygenase inhibitors and immune-suppressive drugs were inactive at 30 mu M against LPS and zymosan A stimulation of cytokine release. Using zymosan A as the stimulus, only SKF-86002 (30 mu M) showed significant inhibition of IL-1 beta (-59%). This 4 h human blood assay has the potential to identify novel inhibitors and sites of actions (e.g. transcription, post-transcriptional and secretion) of new antiinflammatory drugs.