Matsunaga T, Hirayama F, Yonemura Y, Murray R, Ogawa M
Department of Veterans Affairs Medical Center and the Department of Medicine, Medical University of South Carolina, Charleston, SC, USA.
Blood. 1998 Aug 1;92(3):901-7.
The receptors for interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-5 share a common signaling subunit betac. However, in the mouse, there is an additional IL-3 signaling protein, betaIL-3, which is specific for IL-3. We have previously reported that IL-3 abrogates the lymphoid potentials of murine lymphohematopoietic progenitors and the reconstituting ability of hematopoietic stem cells. We used bone marrow cells from betac- and betaIL-3-knock-out mice to examine the relative contributions of the receptor proteins to the negative regulation by IL-3. First, we tested the effects of IL-3 on lymphohematopoietic progenitors by using lineage-negative (Lin-) marrow cells of 5-fluorouracil (5-FU)-treated mice in the two-step methylcellulose culture we reported previously. Addition of IL-3 to the combination of steel factor (SF, c-kit ligand) and IL-11 abrogated the B-lymphoid potential of the marrow cells of both types of knock-out mice as well as wild-type mice. Next, we investigated the effects of IL-3 on in vitro expansion of the hematopoietic stem cells. We cultured Lin-Sca-1-positive, c-kit-positive marrow cells from 5-FU-treated mice in suspension in the presence of SF and IL-11 with or without IL-3 for 7 days and tested the reconstituting ability of the cultured cells by transplanting the cells into lethally irradiated Ly-5 congenic mice together with "compromised" marrow cells. Presence of IL-3 in culture abrogated the reconstituting ability of the cells from both types of knock-out mice and the wild-type mice. In contrast, addition of GM-CSF to the suspension culture abrogated neither B-cell potential nor reconstituting abilities of the cultured cells of wild-type mice. These observations may have implications in the choice of cytokines for use in in vitro expansion of human hematopoietic stem cells and progenitors.
白细胞介素-3（IL-3）、粒细胞-巨噬细胞集落刺激因子（GM-CSF）和IL-5的受体共享一个共同的信号亚基βc。然而，在小鼠中，存在一种额外的IL-3信号蛋白βIL-3，它对IL-3具有特异性。我们之前报道过，IL-3可消除小鼠淋巴造血祖细胞的淋巴潜能以及造血干细胞的重建能力。我们使用βc和βIL-3基因敲除小鼠的骨髓细胞来研究受体蛋白对IL-3负调控的相对贡献。首先，我们通过在我们之前报道的两步甲基纤维素培养中使用经5-氟尿嘧啶（5-FU）处理的小鼠的谱系阴性（Lin-）骨髓细胞，测试了IL-3对淋巴造血祖细胞的影响。在将钢因子（SF，c-kit配体）和IL-11联合使用时添加IL-3，消除了两种基因敲除小鼠以及野生型小鼠骨髓细胞的B淋巴细胞潜能。接下来，我们研究了IL-3对造血干细胞体外扩增的影响。我们在有或没有IL-3的情况下，将经5-FU处理的小鼠的Lin-Sca-1阳性、c-kit阳性骨髓细胞在SF和IL-11存在下悬浮培养7天，并通过将培养的细胞与“受损”骨髓细胞一起移植到经致死性照射的Ly-5同基因小鼠中，测试培养细胞的重建能力。培养中存在IL-3消除了两种基因敲除小鼠和野生型小鼠细胞的重建能力。相比之下，向悬浮培养中添加GM-CSF既没有消除野生型小鼠培养细胞的B细胞潜能，也没有消除其重建能力。这些观察结果可能对用于人造血干细胞和祖细胞体外扩增的细胞因子的选择具有启示意义。
