HMGB1对小鼠腹腔巨噬细胞吞噬和I-A/E表达的影响

Effect of high mobility group B1 protein on the function of phagocytosis and the expression of I-A/-E of peritoneal macrophages in mice

目的：探讨HMGB1对巨噬细胞免疫功能的影响。方法：梯度浓度HMGB1处理小鼠腹腔巨噬细胞,或将小鼠随机分为生理盐水对照、24h和48h高与低剂量HMGB1注射组,腹腔注射0.2μg或20μg HMGB1,或生理盐水。检测巨噬细胞吞噬功能和I-A/E表达。结果：10μg/L HMGB1刺激6-12h,巨噬细胞吞噬功能较其他剂量组明显增强（P〈0.05或P〈0.01）。HMGB1对培养巨噬细胞I-A/-E表达无影响。高剂量HMGB1攻击小鼠24h,其腹腔巨噬细胞吞噬能力明显降低（P〈0.05）;低剂量HMGB1攻击48h,巨噬细胞I-A/-E表达明显上调（P〈0.05或P〈0.01）。结论：高剂量HMGB1抑制巨噬细胞吞噬功能,低剂量HMGB1增强巨噬细胞免疫功能。

AIM： To investigate the effect of extracellular high mobility group B1 protein（HMGB1） on the immunological function of macrophages.METHODS： Peritoneal macrophages from mice were stimulated by concentration gradient HMGB1 in vitro.Male BALB/c mice were divided randomly into control group（normal saline,i.p.）,low or high dose group（treated with HMGB1 0.2 μg or 20 μg per mouse,respectively,i.p.）.Phagocytosis of neutral red and I-A/-E expression of macrophages was assayed.RESULTS：（1） HMGB1 regulated the phagocytosis of macrophages in a time-and dose-dependent manner,but it did not regulate the expression of I-A/-E in vitro.Moreover,the phagocytosis of macrophages was significantly enhanced by stimulating of HMGB1 at a concentration of 10 μg/L as compared with other stimulating concentrations at culture-hour 6 and 12（P〈0.05 or P〈0.01）.（2） The capacity for phagocytosis of macrophages was reduced from 43% to 67% when the mice were challenged with HMGB1 in vivo.However,as compared with animals in control group,neutral red phagocytosis of macrophages was depressed markedly in the animals inflicted with high dose HMGB1 for 24 hours（P〈0.05）.The I-A/-E expression of macrophages was up-regulated markedly in the animals inflicted with low dose HMGB1 for 48 hours as compared to animals treated with normal saline and high dose HMGB1（P〈0.05 or P〈0.01）.CONCLUSION： High dose HMGB1 can depress the phagocytosis of macrophages,and low dose HMGB1 can enhance macrophage-mediated immunity.Moderate HMGB1 loading is beneficial to immune defense.