Steiniger B, Barth P, Herbst B, Hartnell A, Crocker P R
Institute of Anatomy and Cell Biology, University of Marburg, Germany.
Immunology. 1997 Oct;92(2):307-16. doi: 10.1046/j.1365-2567.1997.00328.x.
The microanatomical structure of human and rat splenic white pulp is compared, with special emphasis on the localization of the marginal zone occupied by immunoglobulin M (IgM)+ IgD-/dull B lymphocytes and its specialized macrophages. Our study reveals that in contrast to rats, the marginal zone of humans primarily exists in the vicinity of primary and secondary splenic follicles and that it is almost absent around the periarteriolar T-cell zones. We demonstrate that in humans there is an additional compartment, the perifollicular zone, located between the marginal zone and the red pulp. The perifollicular zone is a dynamic region of variable cellular and phenotypic composition, which can be regarded either as a part of the red pulp or of the follicles. In most cases the perifollicular zone appears as a compartment of the red pulp containing erythrocyte-filled spaces which differ from the typical red pulp sinusoids. Similar to the splenic cords, the perifollicular zone mostly harbours scattered B and T lymphocytes. However, sometimes B lymphocytes clearly predominate in the perifollicular area. In addition, strongly sialoadhesin-positive macrophages form sheaths around capillaries in the perifollicular zone. Such capillary sheaths are not observed in rats. In humans weakly sialoadhesin-positive macrophages are also present in the perifollicular zone and in the red pulp. In some specimens sialoadhesin is, however, strongly expressed by a large number of dispersed perifollicular macrophages. Interestingly, in striking contrast to rats, the human marginal zone does not contain sialoadhesin-positive macrophages and marginal metallophilic macrophages are also absent in humans. Thus, sialoadhesin-positive macrophages and IgM+ IgD- memory B lymphocytes both share the marginal zone as a common compartment in rats, while they occupy different compartments in humans. We show that the human splenic marginal zone does not contain a marginal sinus and assume that in humans the perifollicular region is the compartment where antigen and recirculating lymphocytes enter the organ.
对人和大鼠脾脏白髓的微观解剖结构进行了比较，特别强调了由免疫球蛋白M（IgM）+ IgD-/暗B淋巴细胞及其特化巨噬细胞占据的边缘区的定位。我们的研究表明，与大鼠不同，人类的边缘区主要存在于初级和次级脾滤泡附近，而在动脉周围T细胞区周围几乎不存在。我们证明，在人类中存在一个额外的区域，即滤泡周区，位于边缘区和红髓之间。滤泡周区是一个细胞和表型组成可变的动态区域，可被视为红髓或滤泡的一部分。在大多数情况下，滤泡周区表现为红髓的一个区域，包含充满红细胞的空间，这些空间与典型的红髓血窦不同。与脾索相似，滤泡周区主要含有散在的B和T淋巴细胞。然而，有时B淋巴细胞在滤泡周区明显占主导地位。此外，强唾液酸粘附素阳性巨噬细胞在滤泡周区的毛细血管周围形成鞘。在大鼠中未观察到这种毛细血管鞘。在人类中，弱唾液酸粘附素阳性巨噬细胞也存在于滤泡周区和红髓中。然而，在一些标本中，大量分散的滤泡周巨噬细胞强烈表达唾液酸粘附素。有趣的是，与大鼠形成鲜明对比的是，人类边缘区不包含唾液酸粘附素阳性巨噬细胞，人类也不存在边缘嗜金属巨噬细胞。因此，唾液酸粘附素阳性巨噬细胞和IgM+ IgD-记忆B淋巴细胞在大鼠中共享边缘区作为一个共同区域，而在人类中它们占据不同的区域。我们表明，人类脾边缘区不包含边缘窦，并假设在人类中，滤泡周区域是抗原和再循环淋巴细胞进入器官的区域。
