Factors involved in regulation of polymorphonuclear neutrophils apoptosisin vitro

AIM:This study aimed at elucidated the possibility that prevent tissue from secondary injury by regulating polymorphonuclear neutrophil (PMN) apoptosisin vitro. METHODS:Neutrophils, isolated from peripheral blood, were incubated with sodium arsenite (Ars), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), burned serum and traumatic serum, respectively. Apoptosis rate, expression of CD11b, respiratory burst and concentration of Ca²⁺ were then measured. RESULTS:The elevation of PMN apoptosis rate was Ars concentration dependent, but activated PMN became insensitive to Ars. IL-6 delayed PMN apoptosis (compared with control at 24 h,P＜0.05), inhibited CD11b expression. Burned and traumatic serum had more significant effects on PMN compared with IL-6. CONCLUSION:PMN was observed for the first time to resist spontaneous apoptosis when activated by LPS/TNF, and became insensitive to apoptosis-inducing substance Ars. IL-6, burned serum and traumatic serum could delay PMN apoptosis and recover PMN functions partly.