Matsukawa A, Miyazaki S, Maeda T, Tanase S, Feng L, Ohkawara S, Yoshinaga M, Yoshimura T
Department of Pathology, Kumamoto University School of Medicine, Honjo, Japan.
Lab Invest. 1998 Aug;78(8):973-85.
The production of monocyte chemoattractant protein-1 (MCP-1) and its regulation by TNFalpha, IL-1, and IL-8 were investigated in two rabbit models of arthritis induced by intra-articular injection of lipopolysaccharide (LPS) or monosodium urate (MSU) crystals. We first prepared recombinant rabbit MCP-1 and antibodies and then developed an immunoassay. The immunoassay detected 3 pg/ml rabbit MCP-1 and did not cross-react with other rabbit chemokines such as IL-8 or GRO. MCP-1 was first detected in synovial fluid (SF) at 1 hour, and peaked at 4 or 2 hours after the injection of LPS or MSU crystals, respectively. Immunohistochemically, MCP-1 was detected in synovial lining cells and infiltrating neutrophils. The amounts of MCP-1 detected in SF from neutrophil-depleted rabbits were similar to those in normal rabbits, suggesting that synovial lining cells were the main source of MCP-1 detected in SF. The peak level of MCP-1 in SF after LPS-injection was inhibited by 57% with anti-TNFalpha mAb and by 41% with IL-1 receptor antagonist (IL-1Ra). Coadministration of anti-TNFalpha mAb and IL-1Ra inhibited 90% of MCP-1 production. In contrast, the peak level of MCP-1 in SF after MSU crystal-injection was not affected by any cytokine inhibitor, but was reduced by 52% with coadministration of anti-TNFalpha mAb and IL-1Ra. Anti-IL-8 IgG had no effect on the production of MCP-1 in either model. Thus, the production of MCP-1 in LPS-induced arthritis was mostly regulated by TNFalpha and IL-1, whereas half the extent of MCP-1 production in MSU crystal-induced arthritis was independent of TNFalpha or IL-1. IL-8 does not seem to regulate the production of MCP-1 in SF either directly or indirectly. Finally, administration of neutralizing anti-MCP-1 antibody inhibited LPS- and MSU crystal-induced monocyte infiltration by 58.4% and 44.9%, respectively, suggesting that synovial production of MCP-1 plays an important role in the recruitment of monocytes in these arthritis models.
在通过关节内注射脂多糖（LPS）或尿酸钠（MSU）晶体诱导的两种兔关节炎模型中，研究了单核细胞趋化蛋白-1（MCP-1）的产生及其受肿瘤坏死因子α（TNFα）、白细胞介素-1（IL-1）和白细胞介素-8（IL-8）的调节情况。我们首先制备了重组兔MCP-1和抗体，然后开发了一种免疫测定法。该免疫测定法可检测到3 pg/ml的兔MCP-1，且不与其他兔趋化因子如IL-8或生长调节致癌基因蛋白（GRO）发生交叉反应。在注射LPS或MSU晶体后1小时首次在滑液（SF）中检测到MCP-1，分别在注射LPS或MSU晶体后4小时或2小时达到峰值。免疫组织化学检测显示，在滑膜衬里细胞和浸润的中性粒细胞中可检测到MCP-1。在中性粒细胞减少的兔的SF中检测到的MCP-1量与正常兔相似，这表明滑膜衬里细胞是在SF中检测到的MCP-1的主要来源。注射LPS后SF中MCP-1的峰值水平用抗TNFα单克隆抗体（mAb）抑制了57%，用IL-1受体拮抗剂（IL-1Ra）抑制了41%。联合使用抗TNFα mAb和IL-1Ra可抑制90%的MCP-1产生。相比之下，注射MSU晶体后SF中MCP-1的峰值水平不受任何细胞因子抑制剂的影响，但联合使用抗TNFα mAb和IL-1Ra可使其降低52%。抗IL-8 IgG对两种模型中MCP-1的产生均无影响。因此，LPS诱导的关节炎中MCP-1的产生主要受TNFα和IL-1调节，而MSU晶体诱导的关节炎中MCP-1产生程度的一半独立于TNFα或IL-1。IL-8似乎不直接或间接调节SF中MCP-1的产生。最后，给予中和性抗MCP-1抗体分别抑制了LPS和MSU晶体诱导的单核细胞浸润58.4%和44.9%，这表明滑膜产生的MCP-1在这些关节炎模型中单核细胞的募集中起重要作用。
