Bliss C M, Golenbock D T, Keates S, Linevsky J K, Kelly C P
Section of Gastroenterology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
Infect Immun. 1998 Nov;66(11):5357-63. doi: 10.1128/IAI.66.11.5357-5363.1998.
Helicobacter pylori gastritis is characterized by leukocyte infiltration of the gastric mucosa. The aims of this study were to determine whether H. pylori-derived factors stimulate chemokine release from human monocytes and to ascertain whether H. pylori lipopolysaccharide (LPS) may be responsible for this effect. Human peripheral blood monocytes were exposed to an H. pylori water extract (HPE) or to purified H. pylori LPS. Levels of the chemokines interleukin-8 (IL-8), epithelial neutrophil-activating peptide 78 (ENA-78), and monocyte chemotactic protein 1 (MCP-1) were measured by enzyme-linked immunosorbent assay. The contribution of H. pylori LPS to monocyte activation was determined by using the LPS antagonist Rhodobacter sphaeroides lipid A (RSLA) and a blocking monoclonal antibody to CD14 (60bca). HPE increased monocyte secretion of IL-8, ENA-78, and MCP-1. Heat treatment of HPE did not reduce its ability to activate monocytes. Purified H. pylori LPS also stimulated monocyte chemokine production but was 1,000-fold less potent than Salmonella minnesota lipid A. RSLA blocked H. pylori LPS-induced monocyte IL-8 release in a dose-dependent fashion (maximal inhibition 82%, P < 0.001). RSLA also inhibited HPE-induced IL-8 release (by 93%, P < 0.001). The anti-CD14 monoclonal antibody 60bca substantially inhibited IL-8 release from HPE-stimulated monocytes (by 88%, P < 0.01), whereas the nonblocking anti-CD14 monoclonal antibody did not. These experiments with potent and specific LPS inhibitors indicate that the main monocyte-stimulating factor in HPE is LPS. H. pylori LPS, acting through CD14, stimulates human monocytes to release the neutrophil-activating chemokines IL-8 and ENA-78 and the monocyte-activating chemokine MCP-1. Despite its low relative potency, H. pylori LPS may play an important role in the pathogenesis of H. pylori gastritis.
幽门螺杆菌胃炎的特征是胃黏膜有白细胞浸润。本研究的目的是确定幽门螺杆菌衍生因子是否刺激人单核细胞释放趋化因子，并确定幽门螺杆菌脂多糖（LPS）是否可能是造成这种效应的原因。将人外周血单核细胞暴露于幽门螺杆菌水提取物（HPE）或纯化的幽门螺杆菌LPS中。通过酶联免疫吸附测定法测量趋化因子白细胞介素-8（IL-8）、上皮中性粒细胞激活肽78（ENA-78）和单核细胞趋化蛋白1（MCP-1）的水平。通过使用LPS拮抗剂球形红杆菌脂多糖（RSLA）和针对CD14的阻断性单克隆抗体（60bca）来确定幽门螺杆菌LPS对单核细胞激活的作用。HPE增加了单核细胞IL-8、ENA-78和MCP-1的分泌。对HPE进行热处理并未降低其激活单核细胞的能力。纯化的幽门螺杆菌LPS也刺激单核细胞趋化因子的产生，但效力比明尼苏达沙门氏菌脂多糖低1000倍。RSLA以剂量依赖性方式阻断幽门螺杆菌LPS诱导的单核细胞IL-8释放（最大抑制率82%，P<0.001）。RSLA也抑制HPE诱导的IL-8释放（抑制率93%，P<0.001）。抗CD14单克隆抗体60bca显著抑制HPE刺激的单核细胞释放IL-8（抑制率88%，P<0.01），而非阻断性抗CD14单克隆抗体则无此作用。这些使用强效和特异性LPS抑制剂的实验表明，HPE中主要的单核细胞刺激因子是LPS。幽门螺杆菌LPS通过CD14发挥作用，刺激人单核细胞释放中性粒细胞激活趋化因子IL-8和ENA-78以及单核细胞激活趋化因子MCP-1。尽管幽门螺杆菌LPS的相对效力较低，但它可能在幽门螺杆菌胃炎的发病机制中起重要作用。
