Analysis of hemopoietic lineage of accessory cells in the developing thymus of Xenopus laevis.
Analysis of hemopoietic lineage of accessory cells in the developing thymus of Xenopus laevis.
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DOI：
10.4049/jimmunol.136.2.412
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发表时间：
1986-01
影响因子：
4.4
通讯作者：
J. B. Turpen;P. Smith
中科院分区：
文献类型：
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作者：
J. B. Turpen;P. Smith
通过将造血干细胞移植到细胞遗传学上不同的青蛙胚胎（二倍体- 2n或三倍体- 3n）中，研究了在胸腺循环建立和明显分化定植之前胸腺副细胞的发育历史。用碘化丙啶染色法测定皮质胸腺细胞和循环红细胞的DNA含量，用流式细胞术测定单个细胞核发出的红色荧光量。在玻片上孵育2小时，分离胸腺髓质副细胞。为了进行比较，我们将腹腔巨噬细胞作为具有代表性的髓源性吞噬细胞来研究其发育历史。用DNA特异性Feulgen反应染色法测定贴壁细胞的DNA含量，用微密度法测定单个细胞核的光吸收。胸腺副细胞根据胶乳珠的摄食情况被细分为吞噬型和非吞噬型。胸腺吞噬细胞通常呈非特异性酯酶阳性，表型与腹膜巨噬细胞相似。来自胸腺的非吞噬细胞通常是酯酶阴性，具有树枝状形态，其特征是支状细胞质延伸。甲基绿pyronin y染色显示非吞噬细胞细胞质RNA呈阳性，胸腺和腹腔的吞噬细胞均未检测到细胞质RNA水平。根据携带细胞遗传学标记的细胞比例对胸腺附属细胞的胚胎来源进行分析，表明胸腺淋巴细胞和胸腺附属细胞是一对一致的细胞，不同于骨髓来源的红细胞和可能的巨噬细胞。这些实验提供了间接证据，表明胸腺细胞和胸腺副细胞可能起源于双电位前体，在发育早期胸腺上皮基础定植后分化成这些不同的谱系。
The developmental history of accessory cells in the thymus was studied by grafting hemopoietic stem cells into cytogenetically distinct frog embryos (diploid-2N or triploid-3N) before the establishment of circulation and overt differentiation and colonization of the thymus. The DNA content of cortical thymocytes and circulating erythrocytes was quantified by staining with propidium iodide and measuring the amount of red fluorescence emitted by individual nuclei with the use of flow cytometry. Accessory cells from thymic medulla were separated by incubating for 2 hr on glass slides. For comparison, the developmental history of peritoneal macrophages was examined as representative, myeloid-derived phagocytic cells. DNA content of adherent cells was quantified by staining with the DNA-specific Feulgen reaction and measuring light absorption of individual nuclei by microdensitometry. Thymic accessory cells were subdivided into phagocytic and nonphagocytic phenotypes on the basis of latex bead ingestion. Phagocytic cells in the thymus were usually nonspecific esterase positive and phenotypically resembled peritoneal macrophages. Nonphagocytic cells from the thymus were usually esterase negative and had a dendritic morphology characterized by branched cytoplasmic extensions. Nonphagocytic cells were positive for cytoplasmic RNA based on staining with methyl green-pyronin Y. Phagocytic cells from both the thymus and the peritoneal cavity had no levels of cytoplasmic RNA detectable by this method. Analysis of the embryonic derivation of thymic accessory cells, based on the proportion of cells carrying the cytogenetic marker, demonstrated that thymic lymphocytes and thymic accessory cells were a concordant pair of cells, distinct from myeloid-derived erythrocytes and possibly macrophages. These experiments provide circumstantial evidence suggesting thymocytes and thymic accessory cells could arise from a bipotential precursor that diverges into these separate lineages after colonization of the epithelial thymic rudiment during early development.