Van Vugt E, Van Rijthoven E A, Kamperdijk E W, Beelen R H
Department of Cell Biology and Immunology, Vrije Universiteit, Amsterdam, Netherlands.
Anat Rec. 1996 Feb;244(2):235-45. doi: 10.1002/(SICI)1097-0185(199602)244:2<235::AID-AR11>3.0.CO;2-Q.
Milky spots have been described as reactive structures, their classification varying from inflamed or haematopoietic tissue to lymphoid organs. In this study we investigated the reactivity of the milky spots in the omentum of rats upon induction of a chronic immune response in the peritoneal cavity.
At different time points after intraperitoneal administration of Bacillus Calmette-Guérin (BCG), a peritoneal lavage was made, and the omentum and the draining parathymic lymph nodes were taken out. The cellular composition of these tissues was examined on the light microscopic level, using a panel of monoclonal antibodies, and also by electron microscopy.
During the first 4 months after administering BCG, the number and size of the milky spots increased enormously. Separate macrophage, T, and B cell areas were formed, but interdigitating cells and follicular dendritic cells were not observed. The number of cells in the peritoneal cavity also increased, and the cellular composition showed a strong similarity with that of the milky spots. Especially during the onset of the experiment, most bacteria were observed in the macrophages in the milky spots rather than in the draining lymph nodes. A cellular immune response was observed in the parathymic lymph nodes but not in the milky spots.
Milky spots, either unstimulated or stimulated, should be classified as perivascular infiltrates. They play a role in the initial clearance of bacteria from the peritoneal cavity. Although the large increase in cell number is predominantly caused by immigration of cells, the results do support the role of milky spots as a site for local proliferation and maturation of especially macrophages and also B cells. The obtained data, however, do not support the earlier made assumption that milky spots function as a secondary lymphoid organ in the peritoneal cavity.
乳斑被描述为反应性结构，其分类从炎症或造血组织到淋巴器官各不相同。在本研究中，我们研究了在大鼠腹腔诱导慢性免疫反应后大网膜中乳斑的反应性。
在腹腔注射卡介苗（BCG）后的不同时间点，进行腹腔灌洗，并取出大网膜和引流的胸腺旁淋巴结。使用一组单克隆抗体在光镜水平以及通过电子显微镜检查这些组织的细胞组成。
在接种BCG后的前4个月，乳斑的数量和大小大幅增加。形成了单独的巨噬细胞、T细胞和B细胞区域，但未观察到交错突细胞和滤泡树突状细胞。腹腔内的细胞数量也增加了，其细胞组成与乳斑的细胞组成有很强的相似性。特别是在实验开始时，大多数细菌在乳斑中的巨噬细胞中被观察到，而不是在引流淋巴结中。在胸腺旁淋巴结中观察到细胞免疫反应，但在乳斑中未观察到。
未受刺激或受刺激的乳斑应归类为血管周围浸润。它们在从腹腔中初始清除细菌中起作用。虽然细胞数量的大幅增加主要是由细胞迁移引起的，但结果确实支持乳斑作为特别是巨噬细胞和B细胞局部增殖和成熟位点的作用。然而，所获得的数据不支持早期提出的乳斑在腹腔中作为二级淋巴器官发挥作用的假设。
