ANATOMY OF GERMINAL CENTERS IN MOUSE SPLEEN, WITH SPECIAL REFERENCE TO FOLLICULAR DENDRITIC CELLS
ANATOMY OF GERMINAL CENTERS IN MOUSE SPLEEN, WITH SPECIAL REFERENCE TO FOLLICULAR DENDRITIC CELLS
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DOI：
10.1083/jcb.77.1.148
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发表时间：
1978-01-01
影响因子：
7.8
通讯作者：
STEINMAN, RM
中科院分区：
文献类型：
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作者：
CHEN, LL;ADAMS, JC;STEINMAN, RM
淋巴细胞在生发中心（GC）的增殖可能是由特定树突状细胞表面的细胞外抗原触发的。这些细胞的解剖和功能尚未被直接或详细研究。本文观察了绵羊红细胞刺激对小鼠脾GC发育的影响。滤泡树突状细胞（FDC）存在于GC和次级卵泡的邻近外套膜区域。大，不规则形状的核，含有少量异染色质，允许光镜（LM）鉴定FDC。电镜下细胞呈星状，胞质呈长而薄的片状，可以折叠卷曲成复杂的阵列。这些过程被不同厚度的无定形电子致密材料以及包括可变数量的病毒体的颗粒物在细胞外包覆。FDC细胞质缺乏活跃的分泌细胞和内吞细胞的细胞器，例如发达的粗面内质网（RER）和溶酶体。这些解剖学特征很容易将FDC与其他细胞类型区分开来，即使是那些形状延伸的细胞。静脉注射三种电子致密示踪剂，并在此后1小时至10天处死小鼠。胶体碳，胶体二氧化钍（cThO2）和可溶性辣根过氧化物酶（HRP）被积极隔离到空泡系统的巨噬细胞，但仅在痕量的FDC的catalogorized。根据细胞学和功能标准，FDC不是巨噬细胞。胶体碳和二氧化钍，这是非免疫原，可以在FDC细胞表面上的细胞外几天可视化。其含义尚不清楚，但胶体与FDC的结合似乎减缓了颗粒通过细胞外间隙进入GC的运动。在缺乏GC的脾白色髓中不易鉴别FDC。它们必须可能从体外鉴定的新型树突状细胞重新发育。
Lymphocyte proliferation in germinal centers (GC) is probably triggered by antigen retained extracellularly on the surface of special dendritic cells. The anatomy and function of these cells have not been studied directly or in detail. Mouse spleen GC developing in response to sheep erythrocyte stimulation were examined. Distinctive follicular dendritic cells (FDC) were present in the GC and adjacent mantle region of secondary follicles. The large, irregularly shaped nucleus, containing little heterochromatin, permitted light microscopic (LM) identification of FDC. By EM the cell was stellate in shape sending out long, thin sheets of cytoplasm which could fold and coil into complex arrays. The processes were coated extracellularly by an amorphous electron-dense material of varying thickness, as well as particulates including variable numbers of virions. The FDC cytoplasm lacked organelles of active secretory and endocytic cells, such as well-developed rough endoplasmic reticulum (RER) and lysosomes. These anatomical features readily distinguished FDC from other cell types, even those that were extended in shape. Three electron-dense tracers were injected i.v. and the mice were sacrificed 1 h-10 days thereafter. Colloidal carbon, colloidal thorium dioxide (cThO2) and soluble horseradish peroxidase (HRP) were actively sequestered into the vacuolar system of macrophages but were interiorized only in trace amounts by FDC. FDC are not macrophages by cytologic and functional criteria. Colloidal carbon and thorium dioxide, which are nonimmunogens, could be visualized extracellularly on the cell surface of FDC for several days. The meaning of this is unclear, but the association of colloid with FDC appeared to slow the movement of particulates through the extracellular space into the GC proper. FDC were not readily identified in splenic white pulp lacking GC. They must develop de novo possibly from novel dendritic cells that were identified in vitro.