Hirokawa K, Sado T, Kubo S, Kamisaku H, Hitomi K, Utsuyama M
J Immunol. 1985 Jun;134(6):3615-24.
Immunohistochemical studies were made on the regeneration of T cells of host- and donor-type in the thymus and spleen of radiation bone marrow chimeras by using B10- and B10.BR-Thy-1 congenic mice. Both the thymic cortex and the medulla were first repopulated with thymocytes of irradiated host origin, restoring the normal histologic appearance by days 11 to 14, regardless of the H-2 compatibility between the donor and the host. In Thy-1 congenic chimeras, thymocytes of donor bone marrow origin, less than 100 cells in one thymic lobe, were first recognized at day 7, when the thymus involuted to the smallest size after the irradiation. The thymocytes of donor-type then proliferated exponentially, showing a slightly faster rate when higher doses of bone marrow cells were used for reconstitution, reaching a level of 100 million by day 17 and completely replacing the cortical thymocytes of host origin by day 21. The replacement of cortical thymocytes started from the subcapsular layer in a sporadic manner. The replacement of medullary thymocytes from host- to donor-type occurred gradually between days 21 and 35, after the replacement in the cortex was completed. In the spleen, about 1 million survived cells were recovered at day 3 after the irradiation, and approximately 60% of them were shown to be host-type T cells that were observed in the white pulp areas. The host-type T cells in the spleen increased gradually after day 10, due to the influx of host-type T cells from the regenerating thymus. Thus a pronounced increase of T cells of host-type was immunohistochemically observed in the splenic white pulp between days 21 and 28, when thymocytes of host-type were present mainly in the thymic medulla. These host-type T cells were shown to persist in the spleen for a long time, as long as 420 days after the treatment. Phenotypically, they were predominantly Lyt-1+2+ when examined at day 28, but 5 mo later, they were about 50% Lyt-1+2+ and 50% Lyt-1+2-. Donor-type T cells in the spleen began to appear at about day 14 in chimeras that were transplanted with a larger dose of bone marrow cells, whereas this was slightly delayed in those grafted with a smaller dose of bone marrow cells, starting at about day 28.(ABSTRACT TRUNCATED AT 400 WORDS)
利用B10和B10.BR-Thy-1同源系小鼠，对辐射骨髓嵌合体小鼠胸腺和脾脏中宿主型和供体型T细胞的再生进行了免疫组织化学研究。无论供体与宿主之间的H-2相容性如何，胸腺皮质和髓质首先由受照射宿主来源的胸腺细胞重新填充，在第11至14天恢复正常组织学外观。在Thy-1同源嵌合体中，供体骨髓来源的胸腺细胞，一个胸腺叶中少于100个细胞，在第7天首次被识别，此时胸腺在照射后萎缩到最小尺寸。然后供体型胸腺细胞呈指数增殖，当使用更高剂量的骨髓细胞进行重建时增殖速度略快，在第17天达到1亿个细胞的水平，并在第21天完全取代宿主来源的皮质胸腺细胞。皮质胸腺细胞的替代从被膜下区开始，呈散在性。在皮质替代完成后，髓质胸腺细胞从宿主型向供体型的替代在第21天至35天之间逐渐发生。在脾脏中，照射后第3天回收约100万个存活细胞，其中约60%为在白髓区域观察到的宿主型T细胞。由于来自再生胸腺的宿主型T细胞流入，脾脏中的宿主型T细胞在第10天后逐渐增加。因此，在第21天至28天期间，当宿主型胸腺细胞主要存在于胸腺髓质时，在脾脏白髓中免疫组织化学观察到宿主型T细胞明显增加。这些宿主型T细胞在脾脏中持续存在很长时间，长达治疗后420天。从表型上看，在第28天检查时它们主要是Lyt-1+2+，但5个月后，它们约50%是Lyt-1+2+，50%是Lyt-1+2-。在移植了较大剂量骨髓细胞的嵌合体中，脾脏中的供体型T细胞大约在第14天开始出现，而在移植了较小剂量骨髓细胞的嵌合体中，这一过程略有延迟，大约在第28天开始。（摘要截短于400字）
