Razin E, Leslie K B, Schrader J W
Institute of Biochemistry, Hebrew University, Hadassah Medical School, Jerusalem, Israel.
J Immunol. 1991 Feb 1;146(3):981-7.
Mast cell-fibroblast interactions have been extensively investigated in the last few years. Fibroblasts support the in vitro survival but not proliferation of mouse connective-tissue type mast cells. However, the factor(s) that allow their survival on fibroblast monolayers has not been identified. We have investigated the presence of mRNA for IL-3 and granulocyte-macrophage-CSF in single mouse mast cells, before and after co-culture with 3T3 fibroblasts, using the polymerase chain reaction technique. The system was calibrated first by using in vitro generated population of mouse bone-marrow derived mast cells (BMMC). Significant differences in the amplification of IL-3 cDNA were observed in each of the BMMC cells examined, whereas the amplification of cDNA for the alpha-subunit of the Fc epsilon RI were similar. Inasmuch as murine cultured IL-3-dependent mast cells differentiate into connective tissue-like mast cells when co-cultured with 3T3 fibroblasts without any exogenous supply of growth factors, it was of interest to determine whether these connective tissue-like mast cells produce IL-3 message. Separation of the differentiated BMMC from the fibroblast monolayer, by either trypsinization or by single cell manipulation revealed the synthesis of a detectable amount of IL-3 mRNA in these mast cells. Whether this IL-3 mRNA was induced by fibroblasts was further investigated using connective tissue mast cells freshly purified from the mouse peritoneal cavity. Only about 20% of these connective tissue mast cells produced detectable amount of granulocyte-macrophage-CSF mRNA whereas in less than 10% of the cells IL-3 mRNA was detected. However, when these connective tissue mast cells were co-cultured with 3T3 fibroblasts for 18 hours and then separated, IL-3 mRNA were detected in most of the cells whereas no such mRNA was detected in tissue mast cells incubated for 18 h with medium derived from 3T3 fibroblasts. Therefore we conclude that fibroblasts induce the accumulation of IL-3 mRNA in connective tissue mast cells. The production of IL-3 may play a role in the survival of this type of mast cells on the fibroblast monolayer.
在过去几年中，肥大细胞与成纤维细胞之间的相互作用已得到广泛研究。成纤维细胞支持小鼠结缔组织型肥大细胞在体外存活，但不支持其增殖。然而，尚未确定使它们在成纤维细胞单层上存活的因素。我们使用聚合酶链反应技术，研究了与3T3成纤维细胞共培养前后，单个小鼠肥大细胞中IL-3和粒细胞-巨噬细胞集落刺激因子（GM-CSF）的mRNA表达情况。该系统首先通过使用体外产生的小鼠骨髓来源肥大细胞（BMMC）群体进行校准。在所检测的每个BMMC细胞中，IL-3 cDNA的扩增存在显著差异，而FcεRIα亚基的cDNA扩增相似。由于小鼠培养的IL-3依赖性肥大细胞在与3T3成纤维细胞共培养时，无需任何外源性生长因子供应就能分化为结缔组织样肥大细胞，因此确定这些结缔组织样肥大细胞是否产生IL-3信息很有意义。通过胰蛋白酶消化或单细胞操作将分化的BMMC与成纤维细胞单层分离后发现，这些肥大细胞中合成了可检测量的IL-3 mRNA。使用从小鼠腹腔新鲜纯化的结缔组织肥大细胞，进一步研究了这种IL-3 mRNA是否由成纤维细胞诱导产生。这些结缔组织肥大细胞中只有约20%产生了可检测量的粒细胞-巨噬细胞集落刺激因子mRNA，而在不到10%的细胞中检测到了IL-3 mRNA。然而，当这些结缔组织肥大细胞与3T3成纤维细胞共培养18小时然后分离时，大多数细胞中检测到了IL-3 mRNA，而在与3T3成纤维细胞培养基孵育18小时的组织肥大细胞中未检测到此类mRNA。因此我们得出结论，成纤维细胞诱导结缔组织肥大细胞中IL-3 mRNA的积累。IL-3的产生可能在这类肥大细胞在成纤维细胞单层上的存活中起作用。
