Wendling F, Vigon I, Souyri M, Tambourin P
Laboratoire Immunologie et Oncologie des Maladies Rétrovirales, Hôpital Cochin, Paris, France.
Leukemia. 1989 Jul;3(7):475-80.
The myeloproliferative leukemia virus (MPLV) is an acute leukemogenic, nonsarcomatogenic replication-defective murine retrovirus which carries a novel oncogene, termed mpl. We recently reported that both late and early erythroid progenitors from MPLV-infected mice acquire erythropoietin and growth factor independence. In the present study, we show that MPLV-infected pluripotent, granulomacrophage and megakaryocyte progenitor cells proliferated and differentiated in semisolid cultures in the absence of the exogenous growth factors which are absolutely required for colony formation of normal hematopoietic progenitor cells. These factor-independent colonies were morphologically and cytologically similar to normal colonies and did not show any sign of impaired differentiation. Factor-independent colony formation was not influenced by the seeding density. MPLV-infected cells were unable to stimulate colony development of uninfected progenitors in coculture assays, and retransplanted clusters continued to grow in the absence of accessory cells. These data suggest that spontaneous colony formation does not result from a paracrine secretion of growth factors and indicate that MPLV is unique among naturally occurring murine retrovirus for its ability to abrogate the growth factor requirements of a broad spectrum of hematopoietic progenitor cells.
骨髓增殖性白血病病毒（MPLV）是一种急性致白血病、非致肉瘤性的复制缺陷型鼠逆转录病毒，它携带一种名为mpl的新致癌基因。我们最近报道，来自感染MPLV小鼠的晚期和早期红系祖细胞均获得了对促红细胞生成素和生长因子的独立性。在本研究中，我们发现，在缺乏正常造血祖细胞集落形成绝对需要的外源性生长因子的情况下，感染MPLV的多能、粒巨噬细胞和巨核细胞祖细胞在半固体培养中增殖并分化。这些不依赖因子的集落在形态和细胞学上与正常集落相似，且未显示出任何分化受损的迹象。不依赖因子的集落形成不受接种密度的影响。在共培养试验中，感染MPLV的细胞无法刺激未感染祖细胞的集落发育，并且重新移植的细胞团在没有辅助细胞的情况下继续生长。这些数据表明，自发集落形成并非由生长因子的旁分泌分泌所致，并且表明MPLV在天然存在的鼠逆转录病毒中因其能够消除多种造血祖细胞对生长因子的需求而具有独特性。
