Wisniewski D, Strife A, Atzpodien J, Clarkson B D
Cancer Res. 1987 Sep 15;47(18):4788-94.
Previous studies using unseparated normal human bone marrow cells have indicated that recombinant tumor necrosis factor alpha (rTNF-alpha) can inhibit the in vitro colony growth by normal granulocyte/macrophage (CFU-GM) and erythroid (BFU-E) progenitor cells in a dose-dependent manner. In the present studies, by using very low numbers of highly enriched normal bone marrow progenitor cell populations as target cells, we have extended these previous findings to provide convincing evidence that erythroid and myeloid colony growth suppression by rTNF-alpha is manifested by a direct interaction between rTNF-alpha and CFU-GM and BFU-E progenitor cells. In addition, the sensitivity of normal peripheral blood and chronic myeloid leukemia bone marrow CFU-GM and BFU-E colony growth to inhibition by rTNF-alpha was examined and found to be comparable with that of normal bone marrow CFU-GM and BFU-E. Although the continuous presence of high doses of rTNF-alpha (5000 units/ml) was required in methylcellulose cultures for maximal CFU-GM (90%) and BFU-E (70%) colony suppression, short-term exposure (24 to 72 hr) of normal bone marrow-enriched progenitor cells to rTNF-alpha, in the absence of hematopoietic growth factors, was sufficient to irreversibly suppress up to 50 to 65% of CFU-GM colony growth. In contrast, the number of BFU-E colonies was increased under these conditions. If, however, hematopoietic growth factors (Mo-T-cell-conditioned medium and erythropoietin) were present during preincubation of the cells with rTNF-alpha, BFU-E were then slightly suppressed while the extent of CFU-GM inhibition remained essentially the same. The suppressive effect of rTNF-alpha on erythroid and myeloid progenitor cell growth appears to be most pronounced on the more primative stages of committed progenitor cell development, since inhibition of CFU-GM- and BFU-E-derived colony growth progressively decreased with the delayed addition of rTNF-alpha to methylcellulose cultures. [3H]Thymidine incorporation was also inhibited by rTNF-alpha in normal bone marrow-enriched progenitor cell populations stimulated to proliferate in liquid culture by colony-stimulating factors. This effect was transient, however, since the activity of rTNF-alpha declined after the first 24 h of culture at 37 degrees C, particularly at low doses of rTNF-alpha where the activity was completely lost after 48 h of culture. This loss of activity appeared to be due to a decreased sensitivity of progenitor cells to the antiproliferative effects of tumor necrosis factor (TNF) after an initial exposure rather than a lack of available TNF.(ABSTRACT TRUNCATED AT 400 WORDS)
以往使用未分离的正常人骨髓细胞进行的研究表明，重组肿瘤坏死因子α（rTNF-α）能够以剂量依赖的方式抑制正常粒细胞/巨噬细胞（CFU-GM）和红系（BFU-E）祖细胞的体外集落生长。在本研究中，通过使用极少量高度富集的正常骨髓祖细胞群体作为靶细胞，我们扩展了这些先前的发现，以提供令人信服的证据，即rTNF-α对红系和髓系集落生长的抑制是通过rTNF-α与CFU-GM和BFU-E祖细胞之间的直接相互作用来体现的。此外，还检测了正常外周血和慢性髓性白血病骨髓CFU-GM和BFU-E集落生长对rTNF-α抑制的敏感性，发现与正常骨髓CFU-GM和BFU-E的敏感性相当。尽管在甲基纤维素培养中需要持续存在高剂量的rTNF-α（5000单位/毫升）才能实现最大程度的CFU-GM（90%）和BFU-E（70%）集落抑制，但在没有造血生长因子的情况下，将正常骨髓富集的祖细胞短期暴露（24至72小时）于rTNF-α，就足以不可逆地抑制高达50%至65%的CFU-GM集落生长。相比之下，在这些条件下BFU-E集落的数量增加。然而，如果在细胞与rTNF-α预孵育期间存在造血生长因子（Mo-T细胞条件培养基和促红细胞生成素），则BFU-E会受到轻微抑制，而CFU-GM的抑制程度基本保持不变。rTNF-α对红系和髓系祖细胞生长的抑制作用似乎在定向祖细胞发育的更原始阶段最为明显，因为随着向甲基纤维素培养物中延迟添加rTNF-α，CFU-GM和BFU-E来源的集落生长抑制逐渐减弱。在集落刺激因子刺激下在液体培养中增殖的正常骨髓富集祖细胞群体中，[3H]胸苷掺入也受到rTNF-α的抑制。然而，这种作用是短暂的，因为在37℃培养的最初24小时后，rTNF-α的活性下降，特别是在低剂量的rTNF-α情况下，培养48小时后活性完全丧失。这种活性丧失似乎是由于祖细胞在初始暴露后对肿瘤坏死因子（TNF）的抗增殖作用的敏感性降低，而不是缺乏可用的TNF。（摘要截短于400字）
