CONTRIBUTION OF NEUTROPHILS TO LIPOPOLYSACCHARIDE-INDUCED TUMOR-NECROSIS-FACTOR PRODUCTION AND MORTALITY IN A CARRAGEENAN-PRETREATED MOUSE MODEL

Carrageenan (CAR) pretreatment primes mice for lipopolysaccharide (LPS )-induced tumor necrosis factor (TNF)-alpha production in sera and inc reases their mortality rate. To study the contribution of neutrophils in this model, blood neutrophil count was regulated with cyclophospham ide. After LPS challenge, both serum TNF-alpha activity and mortality risk ratio were significantly higher in neutrophilic mice, but signifi cantly lower in neutropenic mice. In vitro, CAR treatment primed for T NF-alpha production of blood neutrophils, but conversely, that of mono cytes was suppressed. We suggest that neutrophils are the major cells to produce TNF-alpha and to determine mouse mortality after LPS challe nge in the mouse CAR model.