Berker Ezel, Kantarci Alpdogan, Hasturk Hatice, Van Dyke Thomas E
Department of Periodontology, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
J Periodontol. 2005 Jun;76(6):964-71. doi: 10.1902/jop.2005.76.6.964.
Neutrophil apoptosis may play a critical role in the resolution of inflammation by stimulating anti-inflammatory cytokine generation from monocytes. In this study, we investigated the effect of apoptotic neutrophils on interleukin (IL)-10 and IL-1beta production from monocytes in response to Porphyromonas gingivalis lipopolysaccharide.
Peripheral blood neutrophils from healthy individuals were isolated by sodium diatrizoate density gradient centrifugation. In order to induce apoptosis, neutrophils were cultured for 24 hours in modified Dulbecco's medium supplemented with 10% autologous serum. Cell apoptosis was quantified by Annexin V positivity and loss of CD16 expression on the cell surface. Peripheral blood mononuclear cells were isolated from the same subjects; monocytes were purified by magnetic cell sorting and cultured with or without apoptotic or fresh neutrophils. Lipopolysaccharide from Porphyromonas gingivalis was used for cell stimulation. IL-1beta and IL-10 levels in supernatants were determined by enzyme-linked immunosorbent assay (ELISA).
IL-10 generation was significantly increased in monocytes cultured with apoptotic neutrophils compared to monocytes alone or cocultured with fresh neutrophils (P <0.05). IL-1beta was suppressed both in resting and lipopolysaccharide-stimulated monocytes in the presence of apoptotic neutrophils compared to monocytes alone or monocytes cultured with fresh neutrophils at all time points (P <0.05).
Neutrophil apoptosis provides a signal to monocytes, changing the phenotype of the monocyte resulting in the production of anti-inflammatory cytokines and suppression of proinflammatory cytokines in response to lipopolysaccharide.
中性粒细胞凋亡可能通过刺激单核细胞产生抗炎细胞因子，在炎症消退过程中发挥关键作用。在本研究中，我们调查了凋亡中性粒细胞对牙龈卟啉单胞菌脂多糖刺激下单核细胞产生白细胞介素（IL）-10和IL-1β的影响。
通过泛影葡胺密度梯度离心法分离健康个体的外周血中性粒细胞。为诱导凋亡，将中性粒细胞在补充有10%自体血清的改良杜氏培养基中培养24小时。通过膜联蛋白V阳性和细胞表面CD16表达缺失来定量细胞凋亡。从同一受试者中分离外周血单个核细胞；通过磁性细胞分选纯化单核细胞，并与凋亡或新鲜中性粒细胞一起或不一起培养。使用牙龈卟啉单胞菌的脂多糖刺激细胞。通过酶联免疫吸附测定（ELISA）测定上清液中IL-1β和IL-10水平。
与单独培养的单核细胞或与新鲜中性粒细胞共培养的单核细胞相比，与凋亡中性粒细胞共培养的单核细胞中IL-10的产生显著增加（P<0.05）。与单独的单核细胞或在所有时间点与新鲜中性粒细胞培养的单核细胞相比，在存在凋亡中性粒细胞的情况下，静息和脂多糖刺激的单核细胞中IL-1β均受到抑制（P<0.05）。
中性粒细胞凋亡向单核细胞提供信号，改变单核细胞的表型，导致产生抗炎细胞因子并抑制脂多糖刺激下促炎细胞因子的产生。
