Jones K H, Stutz E J, Sirinek L P
Department of Cell Biology, Ohio State University, Columbus 43210.
Thymus. 1991 Sep;18(2):67-77.
Primary murine thymus cell cultures consist of thymus epithelial cells, macrophages and interdigitating dendritic cells. Results of the present study indicated that the proportion of macrophage-like cells in cultures was directly related to the age of the thymus donors through 7 weeks of age. We standardized procedures to compare primary thymic cultures derived from mice, 1 day to 115 days of age. Cultures were grown 6 to 8 days and then tested for nonspecific esterase, acid phosphatase, phagocytosis of latex beads, Fc receptors, and MAC-1 staining. Less than 10% macrophage-like cells were identified in cultures from mice 1 to 3 days-old, but the proportion increased to 50% macrophage-like cells in cultures from 7 week-old mice. Thereafter the proportion plateaued although there was considerable variation among older mice. Further studies showed that the proportions of macrophage-like cells was not affected by the number of cells initially seeded into culture, nor by the amount of serum added to the culture medium. These data suggest that macrophage/interdigitating cell precursors immigrate into the thymus for 4 to 6 weeks after birth and support the hypothesis that these precursors may be influenced to differentiate into thymus macrophages or interdigitating cells by the thymic microenvironment.
原代小鼠胸腺细胞培养物由胸腺上皮细胞、巨噬细胞和交错突细胞组成。本研究结果表明，在7周龄以内，培养物中巨噬细胞样细胞的比例与胸腺供体的年龄直接相关。我们规范了程序，以比较来自1日龄至115日龄小鼠的原代胸腺培养物。培养6至8天，然后检测非特异性酯酶、酸性磷酸酶、乳胶珠吞噬作用、Fc受体和MAC-1染色。在1至3日龄小鼠的培养物中，鉴定出的巨噬细胞样细胞不到10%，但在7周龄小鼠的培养物中，这一比例增加到50%的巨噬细胞样细胞。此后，尽管老年小鼠之间存在相当大的差异，但该比例趋于平稳。进一步的研究表明，巨噬细胞样细胞的比例不受最初接种到培养物中的细胞数量的影响，也不受添加到培养基中的血清量的影响。这些数据表明，巨噬细胞/交错突细胞前体在出生后4至6周迁移到胸腺，并支持这样的假设，即这些前体可能受胸腺微环境影响而分化为胸腺巨噬细胞或交错突细胞。
