Bainton D R, Golde D W
J Clin Invest. 1978 Jun;61(6):1555-69. doi: 10.1172/JCI109076.
To study the various stages of human mononuclear phagocyte maturation, we cultivated bone marrow in an in vitro diffusion chamber with the cells growing in suspension and upon a dialysis membrane. At 2, 7, and 14 days, the cultured cells were examined by electron microscopy and cytochemical techniques for peroxidase and for more limited analysis of acid phosphatase and arylsulfatase. Peroxidase was being synthesized in promonocytes of 2- and 7-day cultures, as evidenced by reaction product in the rough-surfaced endoplasmic reticulum, Golgi complex, and storage granules. Peroxidase synthesis had ceased in monocytes and the enzyme appeared only in some granules. By 7 days, large macrophages predominated, containing numerous peroxidase-positive storage granules, and heterophagy of dying cells was evident. By 14 days, the most prevalent cell type was the large peroxidase-negative macrophage. Thus, peroxidase is present in high concentrations in immature cells but absent at later stages, presumably a result of degranulation of peroxidase-positive storage granules. Clusters of peroxidase-negative macrophages with indistinct borders (epithelioid cells), as well as obvious multinucleated giant cells, were noted. Frequently, the interdigitating plasma membranes of neighboring macrophages showed a modification resembling a septate junction--to our knowledge, representing the first documentation of this specialized cell contact between normal macrophages. We suggest that such junctions may serve as zones of adhesion between epithelioid cells.
为了研究人类单核吞噬细胞成熟的各个阶段，我们在体外扩散小室中培养骨髓，细胞在悬浮状态下以及透析膜上生长。在第2天、第7天和第14天，通过电子显微镜和细胞化学技术对培养的细胞进行过氧化物酶检测，并对酸性磷酸酶和芳基硫酸酯酶进行更有限的分析。在培养2天和7天的原单核细胞中可检测到过氧化物酶的合成，粗面内质网、高尔基体复合体和储存颗粒中的反应产物可证明这一点。单核细胞中过氧化物酶的合成已经停止，该酶仅出现在一些颗粒中。到第7天时，大型巨噬细胞占主导地位，含有大量过氧化物酶阳性储存颗粒，并且明显可见对死亡细胞的异噬作用。到第14天时，最普遍的细胞类型是大型过氧化物酶阴性巨噬细胞。因此，过氧化物酶在未成熟细胞中浓度较高，但在后期阶段不存在，推测这是过氧化物酶阳性储存颗粒脱颗粒的结果。注意到边界不清晰的过氧化物酶阴性巨噬细胞簇（上皮样细胞）以及明显的多核巨细胞。相邻巨噬细胞相互交错的质膜经常显示出一种类似于分隔连接的改变——据我们所知，这是正常巨噬细胞之间这种特殊细胞接触的首次记录。我们认为这种连接可能作为上皮样细胞之间的黏附区域。
