细菌脂多糖对小鼠巨噬细胞生长的调节作用

LIPOPOLYSACCHARIDE EFFECTS ON MURINE MACROPHAGE PROLIFERATION

目的研究细菌脂多糖对小鼠巨噬细胞的生长调节作用。方法应用小鼠腹腔渗出性巨噬细胞（ＰＥＭ）和巨噬细胞株Ｊ７７４Ａ．１为靶细胞，测定细菌脂多糖（ＬＰＳ）对Ｍ－ＣＳＦ和ＧＭ－ＣＳＦ刺激的巨噬细胞集落细胞形成的影响，同时用１２５Ⅰ标记的ＧＭ－ＣＳＦ受体结合实验测定了ＬＰＳ对巨噬细胞膜上的ＧＭ－ＣＳＦ受体数目的调节。用反向ＰＣＲ（ＲＴ－ＰＣＲ）法检测ＴＴＧＦ－β１对巨噬细胞产生ＩＦＮ－γ的作用。结果ＬＰＳ单独对巨噬细胞无生长调节作用，但可抑制ＧＭ－ＣＳＦ对巨噬细胞的增殖效应。而在ＴＧＦ－β１同时存在下，ＬＰＳ的抑制效应被消除。ＲＴ－ＰＣＲ证实ＬＰＳ诱生巨噬细胞产生的ＩＦＮ－γ可被ＴＧＦ－β１有效地抑制．而已知ＩＦＮ－γ是强烈的巨噬细胞生长抑制因子。此外，１２５Ⅰ－ＧＭ－ＣＳＦ受体结合实验发现，同ＴＧＦ－β１一样ＬＰＳ增强ＧＭ－ＣＳＦ受体数目的表达。结论ＬＰＳ参与了多种细胞因子对巨噬细胞生长的调节网络，根据存在的细胞因子不同，表现为抑制和增殖的双重作用。

To study bacterial lipopolysaccharide(LPS) effects on murine macrophage proliferation, Methods Murine peritoneal exudate macrophage (PEM) and macrophage cell line J_(774)A. 1 as target, LPS effects on M-CSF and GM-CSF stimulated macrophage colony-forming Cells(CFU-M)were employed.￣(125)Ⅰ-GM-CSF receptor binding assay was used to examine LPS regulation on GMCSF receptor expression。 RT-PCR was developed to test TGF-β1, inhabitation of IFN-γmRNA expression on macrophage induced by LPS. ResuIts In spite of no direct effect on macrophage proliferation, LPS could inhibit the macrophage proliferation stimulated by granulocyte-macrophage colony-stimulating factor(GM-CSF). However, under the concomitant existence of GM-CSF and TGF-β1, the LPS inhibitory effect was deprived. RT-PCR analysis indicated that the strongest macrophage growth inhibitory factor IFN-γmRNA expression in macrophage induced by LPS was remarkably suppressed by TGF-β1.￣(125)Ⅰ-GM-CSF receptor binding assay found that LPS could enhance GMCSF receptor expression as similar as TGF-β1. Conclusions All the resuIts imply that LPS involves in the network of macrophage proliferative regulation by muItiple cytokines displaying inhibitory and stimulatOfy effects dependent on co-existing cytokines.