Righi M, Pierani A, Boglia A, De Libero G, Mori L, Marini V, Ricciardi-Castagnoli P
Department of Pharmacology, University of Milan, Italy.
Oncogene. 1989 Feb;4(2):223-30.
We have obtained a set of oncogenic recombinant retroviruses, the 3RV complex, by cotransfecting murine fibroblasts (SC-1 cells) with plasmids containing the cloned genomes of the avian MH2 and murine AKR viruses. The transfected culture (TAM-2) was shown to release murine transforming viruses by means of reverse transcription and focus formation assays. Analysis of TAM-2 intracellular RNA revealed new transcripts hybridizing with the oncogenes myc and mil and cross-hybridizing with an AKR probe. The biological activity of the 3RV complex was tested for the induction of murine macrophage proliferation in the absence of exogenous growth factors, a property described as the result of mil and myc cooperativity. Cell-free supernatants from 3RV transformed fibroblasts were indeed able to induce the proliferation of macrophage-like cells from murine bone marrow and spleen primary cultures. Such cultures were capable of continuous growth and showed independence from exogenous myeloid growth factors. The cells expressed antigenic markers and functional properties specific of the monocytic-macrophage lineage. These results suggest that transfection-induced recombination could be a novel way to generate biologically active recombinant retroviruses.
我们通过将含有禽MH2病毒和鼠AKR病毒克隆基因组的质粒共转染鼠成纤维细胞（SC-1细胞），获得了一组致癌重组逆转录病毒，即3RV复合体。通过逆转录和焦点形成分析表明，转染培养物（TAM-2）能释放鼠转化病毒。对TAM-2细胞内RNA的分析揭示了与癌基因myc和mil杂交以及与AKR探针交叉杂交的新转录本。在没有外源性生长因子的情况下，测试了3RV复合体诱导鼠巨噬细胞增殖的生物学活性，这种特性被描述为mil和myc协同作用的结果。来自3RV转化成纤维细胞的无细胞上清液确实能够诱导来自鼠骨髓和脾脏原代培养物的巨噬细胞样细胞增殖。这样的培养物能够持续生长，并且显示出不依赖外源性髓系生长因子。这些细胞表达了单核巨噬细胞谱系特有的抗原标志物和功能特性。这些结果表明，转染诱导的重组可能是产生具有生物活性的重组逆转录病毒的一种新方法。
