Péault B, Weissman I L, Baum C, McCune J M, Tsukamoto A
SyStemix, Inc., Palo Alto, California 94303.
J Exp Med. 1991 Nov 1;174(5):1283-6. doi: 10.1084/jem.174.5.1283.
The search for human hematopoietic stem cells has been hampered by the lack of appropriate assay systems. Demonstration of the ability of precursor cell candidates to give rise to T cells is of significant difficulty since dissociated in vitro cultured thymus stroma cells lose their ability to sustain thymocyte maturation. To define further the differentiative capacities of the rare human fetal liver and bone marrow cells that express the CD34 surface antigen and exhibit in vitro myeloid and pre-B cell activities, we have microinjected them into HLA-mismatched fetal thymus fragments, partially depleted of hematopoietic cells by low temperature culture. In vitro colonized thymuses have then been allowed to develop upon engraftment into immunodeficient SCID mice. Using this modification of the SCID-hu system, we show that low numbers of fetal CD34+ progenitor cells can repopulate the lymphoid compartment in the human thymus.
缺乏合适的检测系统阻碍了对人类造血干细胞的寻找。由于体外培养的解离胸腺基质细胞失去了维持胸腺细胞成熟的能力，证明前体细胞候选物产生T细胞的能力极具难度。为了进一步确定表达CD34表面抗原并在体外表现出髓系和前B细胞活性的罕见人类胎儿肝脏和骨髓细胞的分化能力，我们将它们显微注射到经低温培养部分耗尽造血细胞的HLA不匹配的胎儿胸腺片段中。然后将体外定植的胸腺移植到免疫缺陷的SCID小鼠体内使其发育。通过对SCID-hu系统的这种改进，我们表明少量胎儿CD34+祖细胞可以重新填充人类胸腺中的淋巴区室。
