Williams D A, Lim B, Spooncer E, Longtine J, Dexter T M
Division of Hematology-Oncology, Howard Hughes Medical Institute, Boston, MA.
Blood. 1988 Jun;71(6):1738-43.
A recombinant retrovirus (DHFR*-SVADA) in which human adenosine deaminase (ADA) cDNA is transcribed from an internal SV40 promoter was used to infect murine hematopoietic stem and progenitor cells. Human ADA enzyme was not expressed in infected primary murine pluripotent stem cell-derived spleen or progenitor colonies (CFU-GM, CFU-Mix, BFU-E). In contrast, human ADA enzyme activity was readily detected in progenitor colonies derived from immortalized multipotent factor-dependent cells. The level of human enzyme was near endogenous murine enzyme levels and was equivalent in undifferentiated stem cells and differentiated myeloid, erythroid, and mixed colonies. These results indicate that cellular properties other than the stage of differentiation are important in determining the expression of foreign sequences introduced by retroviruses. Cell lines that are immortalized but still capable of induced differentiation may contain factors that abrogate blocks to expression that are manifested in primary hematopoietic stem cells.
一种重组逆转录病毒（DHFR*-SVADA）被用于感染小鼠造血干细胞和祖细胞，在该病毒中，人腺苷脱氨酶（ADA）cDNA从内部SV40启动子转录。在感染的原代小鼠多能干细胞衍生的脾脏或祖细胞集落（CFU-GM、CFU-Mix、BFU-E）中未表达人ADA酶。相反，在源自永生化多能因子依赖性细胞的祖细胞集落中很容易检测到人ADA酶活性。人酶的水平接近内源性小鼠酶水平，并且在未分化的干细胞以及分化的髓系、红系和混合集落中相当。这些结果表明，除了分化阶段之外，细胞特性在决定逆转录病毒引入的外源序列的表达方面也很重要。永生化但仍能够诱导分化的细胞系可能含有消除原代造血干细胞中表现出的表达障碍的因子。
