Ozaki A, Sagartz J E, Capen C C
Tokushima Research Institute, Otsuka Pharmaceutical Company, Ltd., Japan.
Exp Cell Res. 1995 Aug;219(2):547-54. doi: 10.1006/excr.1995.1263.
A rat thyroid cell line (FRTL-5) was used to study the phagocytic activity of thyroid follicular cells using fluorescent latex beads and flow cytometric analysis. Morphologic studies demonstrated that latex beads were engulfed and located within cytoplasmic vacuoles of thyrocytes. Flow cytometric evaluation of cell suspensions revealed high levels of fluorescence in cells engulfing latex beads. Using thyrotropin (TSH) as a stimulator of thyroid function and human interleukin-1 beta as an inhibitor, protocols were established for measuring the effects of these substances on either basal or TSH-induced phagocytosis. Cells exposed to latex beads over time in basal (0H) or TSH-containing medium had an increase in time-dependent phagocytic activity which was maximal after 24 or 8 h, respectively. Treatment of FRTL-5 cells with either a stimulator or an inhibitor revealed maximal change in phagocytic activity after 72 h as measured by the percentage of phagocytic cells as well as the mean fluorescence intensity. Phagocytic activity and iodide trapping by FRTL-5 cells were qualitatively similar in both sensitivity and magnitude of change in the assays used in this study. Phagocytosis of fluorescent latex beads represents a sensitive nonradioactive assay of thyrocyte function whose regulation is similar to iodide trapping.
利用荧光乳胶微球和流式细胞术分析，采用大鼠甲状腺细胞系（FRTL-5）研究甲状腺滤泡细胞的吞噬活性。形态学研究表明，乳胶微球被甲状腺细胞吞噬并位于其细胞质空泡内。对细胞悬液的流式细胞术评估显示，吞噬乳胶微球的细胞呈现高水平荧光。以促甲状腺激素（TSH）作为甲状腺功能刺激剂，人白细胞介素-1β作为抑制剂，建立了测量这些物质对基础或TSH诱导吞噬作用影响的实验方案。在基础（0小时）或含TSH培养基中，随着时间推移暴露于乳胶微球的细胞，其吞噬活性呈时间依赖性增加，分别在24小时或8小时后达到最大值。用刺激剂或抑制剂处理FRTL-5细胞72小时后，通过吞噬细胞百分比和平均荧光强度测量，显示吞噬活性有最大变化。在本研究使用的实验中，FRTL-5细胞的吞噬活性和碘摄取在敏感性和变化幅度上定性相似。荧光乳胶微球的吞噬作用代表了一种敏感的非放射性甲状腺细胞功能检测方法，其调节与碘摄取相似。
