Kawashima I, Zanjani E D, Almaida-Porada G, Flake A W, Zeng H, Ogawa M
Department of Medicine, Medical University of South Carolina, Charleston, USA.
Blood. 1996 May 15;87(10):4136-42.
Using in utero transplantation into fetal sheep, we examined the capability of human bone marrow CD34+ cells fractionated based on Kit protein expression to provide long-term in vivo engraftment. Twelve hundred to 5,000 CD34+ Kit-, CD34+ Kit(low), and CD34+ Kit(high) cells were injected into a total of 14 preimmune fetal sheep recipients using the amniotic bubble technique. Six fetuses were killed in utero 1.5 months after bone marrow cell transplantation. Two fetuses receiving CD34+ Kit(low) cells showed signs of engraftment according to analysis of CD45+ cells in their bone marrow cells and karyotype studies of the colonies grown in methylcellulose culture. In contrast, two fetuses receiving CD34+ Kit(high) cells and two fetuses receiving CD34+ Kit- cells failed to show evidence of significant engraftment. Two fetuses were absorbed. A total of six fetuses receiving different cell populations were allowed to proceed to term, and the newborn sheep were serially examined for the presence of chimerism. Again, only the two sheep receiving CD34+ Kit(low) cells exhibited signs of engraftment upon serial examination. Earlier in studies of murine hematopoiesis, we have shown stage-specific changes in Kit expression by the progenitors. The studies of human cells reported here are in agreement with observations in mice, and indicate that human hematopoietic stem cells are enriched in the Kit(low) population.
通过将细胞移植到子宫内的胎羊体内，我们研究了根据Kit蛋白表达分选的人骨髓CD34+细胞在体内长期植入的能力。使用羊膜囊技术，将1200至5000个CD34+Kit-、CD34+Kit(low)和CD34+Kit(high)细胞注射到总共14只未免疫的胎羊受体中。骨髓细胞移植1.5个月后，6只胎儿在子宫内被处死。根据其骨髓细胞中CD45+细胞的分析以及甲基纤维素培养中生长的集落的核型研究，接受CD34+Kit(low)细胞的2只胎儿显示出植入迹象。相比之下，接受CD34+Kit(high)细胞的2只胎儿和接受CD34+Kit-细胞的2只胎儿未显示出明显植入的证据。2只胎儿被吸收。总共6只接受不同细胞群体的胎儿发育至足月，对新生羊进行系列检查以确定是否存在嵌合体。同样，在系列检查中，只有接受CD34+Kit(low)细胞的2只羊表现出植入迹象。在早期对小鼠造血的研究中，我们已经表明祖细胞中Kit表达存在阶段特异性变化。本文报道的对人细胞的研究与在小鼠中的观察结果一致，表明人造血干细胞在Kit(low)群体中富集。
