大鼠腘窝淋巴结内淋巴滤泡的生后发育

POSTNATAL DEVELOPMENT OF LYMPHOID FOLLICLES IN RAT POPLITEAL LYMPH NODE

目的:研究大鼠淋巴结淋巴滤泡的生后发育.方法:采用常规组织学、免疫细胞化学及三维重建技术研究了大鼠腘窝淋巴结内淋巴滤泡的发生.结果:生后18天始,淋巴结浅层皮质内sIgM阳性B淋巴细胞聚集形成初级淋巴滤泡.生后3周ED-5阳性滤泡树突状细胞出现.随着鼠龄及体重的增长,初级淋巴滤泡不断扩大,每个淋巴结内淋巴滤泡数亦增多.生后13周滤泡数达高峰,平均每个淋巴结86个,13周以后体重缓慢增长,淋巴滤泡数逐渐下降.生后8周时,次级淋巴滤泡出现,ED-5阳性滤泡树突状细胞主要分布于亮区.结论:初级淋巴滤泡形成过程中B淋巴细胞聚集可能诱导局部网状细胞分化成滤泡树突状细胞;发育期间淋巴滤泡数随体重增长而增加可能与某些决定机体生长的因素作用有关.

Objective: To study the postnatal development of lymphoid follicles in rat lymph node. Methods: The conventional histological, immunohistochemical and three dimensional reconstruc-tion technique were used in this study. Results: At 18 days after birth, surface-IgM (slgM)-bearing cells (B lymphocytes) aggregated to form primary follicles in the peripheral cortex of lymph node. At 3 weeks after birth, ED-5 postive follicular dendritic cells (FDC) were detected in the centers of primary follicles. The lymphoid follicles enlarged further and the number of fol-licles per node increased as the age and body weight adveanced. 13 weeks after birth, the number of follicles reached the peak, 86 per node on average. Thereafter, the increase of body weight be-came much lowered and the number of follicles declined gradually. The germinal centers could be recognized in some follicles at 8 weeks. ED-5 positive cells were distributed mainly in the light zone of follicles. Conclusion: The aggregation of B lymphocytes might induce reticular cells to differentiate into FDC and the development of lymphoid follicles in the lymph node could be con-trolled, at least partly, by those factors which can determine the timetable of body growth.