Lemoli R M, Fogli M, Fortuna A, Motta M R, Rizzi S, Benini C, Tura S
Istituto di Ematologia Seràgnoli, Università di Bologna, Italy.
Exp Hematol. 1993 Dec;21(13):1668-72.
We have studied the effects of recombinant human interleukin-11 (rhIL-11), alone and combined with stem cell factor (SCF or c-kit ligand), IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF) on the proliferation of highly enriched human hematopoietic CD34+ and CD34+CD33-DR- progenitor cells. CD34+ cells were purified using the avidin-biotin immunoabsorption technique and CD33+DR+ cells were subsequently removed by immuno-magnetic separation. The colony assays were performed in the presence and absence of exogenous serum. IL-11, as a single agent, induced the growth of a small number of colony-forming units-granulocyte/macrophage (CFU-GM) derived from purified CD34+ cells and failed to support the colony growth of CD34+CD33-DR- cells. The addition of erythropoietin (Epo) to IL-11 induced the growth of erythroid progenitors (BFU-E) derived from CD34+ cells but not from the same population depleted of CD33+DR+ cells. The combination of IL-11 with SCF, IL-3, or GM-CSF, in the presence of Epo, resulted in a synergistic or additive increase in the number of CFU cells (CFU-C) derived from both cell fractions. Moreover, the addition of SCF to IL-11 stimulated the development of macroscopic erythroid and multilineage colonies (CFU-GEMM) containing more than 10(4) cells. A combination of three factors (IL-11, SCF, and IL-3) resulted in the increase of the number of colonies arising from CD34+ and CD34+CD33-DR- cells (but not of their size) compared to the cultures treated with IL-11 plus SCF or IL-11 plus IL-3. The pattern of proliferative response of primitive hematopoietic progenitor cells to IL-11 in serum-free conditions was very similar to the cultures grown in serum-containing medium. It is noteworthy that IL-11 and SCF yielded colony formation that was comparable to that observed in the presence of serum. The effects of IL-11 on CD34+CD33-DR- cells were also studied in a short-term suspension culture system, which was shown to be specific for evaluating the proliferation of pluripotent hematopoietic precursors (Delta assay). In this system, IL-11 had a minimal effect on its own, whereas IL-11 plus SCF acted synergistically and their proliferative activity was improved by the addition of GM-CSF. These experiments indicate that IL-11 may be considered a "permissive" cytokine, capable of initiating the proliferation of very primitive human hematopoietic cells, which are then able to respond to late-acting CSFs.(ABSTRACT TRUNCATED AT 400 WORDS)
我们研究了重组人白细胞介素-11（rhIL-11）单独以及与干细胞因子（SCF或c-kit配体）、白细胞介素-3（IL-3）和粒细胞-巨噬细胞集落刺激因子（GM-CSF）联合使用时，对高度富集的人造血CD34⁺和CD34⁺CD33⁻DR⁻祖细胞增殖的影响。使用抗生物素蛋白-生物素免疫吸附技术纯化CD34⁺细胞，随后通过免疫磁珠分离去除CD33⁺DR⁺细胞。在有或无外源性血清的情况下进行集落测定。IL-11作为单一因子，可诱导源自纯化CD34⁺细胞的少量粒细胞/巨噬细胞集落形成单位（CFU-GM）生长，但无法支持CD34⁺CD33⁻DR⁻细胞的集落生长。向IL-11中添加促红细胞生成素（Epo）可诱导源自CD34⁺细胞而非去除了CD33⁺DR⁺细胞的同一群体的红系祖细胞（BFU-E）生长。在Epo存在的情况下，IL-11与SCF、IL-3或GM-CSF联合使用，可使源自这两种细胞组分的CFU细胞（CFU-C）数量协同或相加增加。此外，向IL-11中添加SCF可刺激含有超过10⁴个细胞的肉眼可见的红系和多系集落（CFU-GEMM）的形成。与用IL-11加SCF或IL-11加IL-3处理的培养物相比，三种因子（IL-11、SCF和IL-3）联合使用可增加源自CD34⁺和CD34⁺CD33⁻DR⁻细胞的集落数量（但不增加其大小）。在无血清条件下，原始造血祖细胞对IL-11的增殖反应模式与在含血清培养基中生长的培养物非常相似。值得注意的是，IL-11和SCF产生的集落形成与在有血清情况下观察到的相当。还在短期悬浮培养系统中研究了IL-11对CD34⁺CD33⁻DR⁻细胞的影响，该系统被证明对评估多能造血前体的增殖具有特异性（Delta测定）。在该系统中，IL-11单独作用时影响最小，而IL-11加SCF具有协同作用，添加GM-CSF可提高它们的增殖活性。这些实验表明，IL-11可被视为一种“许可性”细胞因子，能够启动非常原始的人造血细胞的增殖，这些细胞随后能够对后期作用的集落刺激因子作出反应。（摘要截短至400字）
