CD34+lin-细胞与基质之间的直接接触诱导出一种可溶性活性，该活性可特异性增加原始造血细胞的产生。

Direct contact between CD34+lin- cells and stroma induces a soluble activity that specifically increases primitive hematopoietic cell production.

作者信息

Koller M R, Oxender M, Jensen T C, Goltry K L, Smith A K

机构信息

Aastrom Biosciences, Inc., Ann Arbor, MI 48106, USA.

出版信息

Exp Hematol. 1999 Apr;27(4):734-41. doi: 10.1016/s0301-472x(98)00080-0.

DOI:10.1016/s0301-472x(98)00080-0

PMID:10210331

Abstract

Perfused human bone marrow (BM) mononuclear cell (MNC) cultures result in a greater long-term culture-initiating cell (LTC-IC) output than parallel CD34+lin- cell cultures, even when CD34+lin- cells are placed on irradiated preformed stroma (IPFS). This difference has been attributed to accessory cell effects that are potentiated by medium perfusion. The present study investigated the relative contributions of direct contact- and soluble-mediated mechanisms of accessory cells in this culture system. CD34+lin- cells within (i.e., in contact with) the MNC accessory cell mixture generated greater LTC-IC output than CD34+lin- cells in contact with IPFS. Incubation of CD34+lin- cells with MNC conditioned medium (CM) resulted in partial restoration of MNC accessory activity, while CM from IPFS had no activity on LTC-IC output. Interestingly, the level of LTC-IC output supported by MNC CM was equivalent to that supported by direct contact with IPFS. CD34+lin- cells were then cultured in Transwell inserts either alone, with IPFS (direct contact), or with IPFS below the insert. Direct contact with IPFS significantly increased the output of cells, CFU-GM, and LTC-IC from CD34+lin- cells. IPFS below the insert also resulted in significantly increased cell and CFU-GM output, but did not significantly affect LTC-IC output. Further experiments using CM from CD34+lin- cells and IPFS cultures showed that LTC-IC supportive activity was present only when direct contact was allowed between CD34+lin- cells and IPFS. ELISA and RT-PCR experiments showed that contact did not induce changes in the levels of several known growth factors, including GM-CSF, IL-1beta, IL-3, IL-6, IL-11, LIF, KL, FL, Tpo, TGF-beta, and MIP-1alpha. These results indicate that direct contact between CD34+lin- cells and IPFS induces soluble activity, which specifically increases LTC-IC output from CD34+lin- cell cultures, providing evidence for a novel direct contact-mediated two-way mechanism of communication between primitive hematopoietic cells and stroma.

摘要

灌注培养的人骨髓（BM）单个核细胞（MNC）培养物，其长期培养起始细胞（LTC-IC）产量高于平行的CD34⁺lin⁻细胞培养物，即便将CD34⁺lin⁻细胞接种于经辐照的预制基质（IPFS）上时亦是如此。这种差异归因于辅助细胞效应，而培养基灌注可增强该效应。本研究调查了该培养系统中辅助细胞的直接接触介导机制和可溶性介导机制的相对作用。与IPFS接触的CD34⁺lin⁻细胞相比，处于（即接触）MNC辅助细胞混合物中的CD34⁺lin⁻细胞产生了更高的LTC-IC产量。用MNC条件培养基（CM）孵育CD34⁺lin⁻细胞可部分恢复MNC的辅助活性，而IPFS的CM对LTC-IC产量无活性作用。有趣的是，MNC CM支持的LTC-IC产量水平与直接接触IPFS所支持的水平相当。然后将CD34⁺lin⁻细胞单独培养于Transwell小室中，或与IPFS一起培养（直接接触），或在小室下方放置IPFS培养。与IPFS直接接触显著增加了CD34⁺lin⁻细胞的细胞、CFU-GM和LTC-IC产量。小室下方放置IPFS也导致细胞和CFU-GM产量显著增加，但对LTC-IC产量无显著影响。使用来自CD34⁺lin⁻细胞和IPFS培养物的CM进行的进一步实验表明，只有当CD34⁺lin⁻细胞与IPFS直接接触时才存在LTC-IC支持活性。ELISA和RT-PCR实验表明，接触并未诱导包括GM-CSF、IL-1β、IL-3、IL-6、IL-11、LIF、KL、FL、Tpo、TGF-β和MIP-1α在内的几种已知生长因子水平发生变化。这些结果表明，CD34⁺lin⁻细胞与IPFS之间的直接接触可诱导可溶性活性，特异性增加CD34⁺lin⁻细胞培养物中的LTC-IC产量，为原始造血细胞与基质之间一种新型的直接接触介导双向通讯机制提供了证据。