IDENTIFICATION OF CYCLOPHILIN AS A PROINFLAMMATORY SECRETORY PRODUCT OF LIPOPOLYSACCHARIDE-ACTIVATED MACROPHAGES
IDENTIFICATION OF CYCLOPHILIN AS A PROINFLAMMATORY SECRETORY PRODUCT OF LIPOPOLYSACCHARIDE-ACTIVATED MACROPHAGES
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DOI：
10.1073/pnas.89.8.3511
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发表时间：
1992-04-15
影响因子：
11.1
通讯作者：
CERAMI, A
中科院分区：
文献类型：
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作者：
SHERRY, B;YARLETT, N;CERAMI, A
我们已经从脂多糖刺激的RAW 264.7小鼠巨噬细胞的条件培养基中分离出了一种18 kDa的肽（命名为sp18，用于18 kDa的分泌蛋白）。纯化的sp18在体内具有致炎活性，在体外对人外周血多形核白细胞和单核细胞具有趋化活性。令人惊讶的是，N-末端测序和胰蛋白酶图谱研究表明，sp18和亲环素，一种结合免疫抑制药物环孢素A的细胞内蛋白，是高度同源的。sp18对单核细胞的体外趋化活性被环孢菌素A阻断，但不被环孢菌素H阻断，环孢菌素H是环孢菌素A的结构类似物，不结合亲环素。像纯化的猪亲环素，小鼠sp18表现出肽基脯氨酰顺反异构酶活性。从C57 BL/6小鼠分离的脂多糖刺激的常驻腹腔渗出液巨噬细胞条件培养基中含有比非刺激巨噬细胞条件培养基显著更高水平的sp18/亲环素。sp18/亲环素表现出促炎活性并由巨噬细胞响应内毒素分泌的观察结果表明，这种蛋白质可能作为细胞因子发挥作用，并邀请环孢菌素A的免疫抑制作用部分来自与作为免疫和炎症功能介体释放的亲环素的细胞外形式的相互作用的假设。
We have isolated an 18-kDa peptide (designated sp18, for 18-kDa secreted protein) from the conditioned medium of lipopolysaccharide-stimulated RAW 264.7 murine macrophages. Purified sp18 had in vivo inflammatory activity and in vitro chemotactic activity for human peripheral blood polymorphonuclear leukocytes and monocytes. Surprisingly, N-terminal sequencing and tryptic mapping studies revealed that sp18 and cyclophilin, an intracellular protein that binds the immunosuppressive drug cyclosporin A, are highly homologous. The in vitro chemotactic activity of sp18 on monocytes was blocked by cyclosporin A but not by cyclosporin H, a structural analog of cyclosporin A that does not bind cyclophilin. Like purified porcine cyclophilin, mouse sp18 exhibited peptidyl-prolyl cis-trans isomerase activity. Medium conditioned by lipopolysaccharide-stimulated resident peritoneal exudate macrophages isolated from C57BL/6 mice contained substantially higher levels of sp18/cyclophilin than medium conditioned by nonstimulated macrophages. The observation that sp18/cyclophilin exhibits proinflammatory activity and is secreted by macrophages in response to endotoxin suggests that this protein may function as a cytokine, and invites the hypothesis that the immunosuppressive action of cyclosporin A results in part from interaction with an extracellular form of cyclophilin released as a mediator of immune and inflammatory functions.