Demello Daphne E, Mahmoud Sohir, Ryerse Jan, Hoffmann Joseph W
Department of Pathology, St. Louis University Health Sciences Center and Pediatric Research Institute, Cardinal Glennon Children's Hospital, Missouri 63104, USA.
In Vitro Cell Dev Biol Anim. 2002 Mar;38(3):154-64. doi: 10.1290/1071-2690(2002)038<0154:GACOAC>2.0.CO;2.
The Clara cell is believed to be the progenitor of the peripheral airway epithelium, and it produces the surfactant proteins SP-A and SP-B, in addition to the 10-kDa Clara cell secretory protein (CCSP or CC10). To date, attempts to develop Clara cell lines have been unsuccessful. Most such attempts have involved the in vitro insertion of a transforming viral oncogene. We have reported previously the characterization of a differentiated conditionally immortalized murine lung Type II epithelial cell line, T7, from the H-2Kb-tsA58 transgenic mouse. We have also used this mouse model to derive Clara cell lines. In this model, the need for in vitro gene insertion is circumvented by the creation of a transgene, in which the large tumor antigen of a temperature-sensitive strain (tsA58) of the simian virus 40 (SV40) is fused with the major histocompatibility complex promoter H-2Kb. The promoter is active in a wide range of tissues and is induced by interferons (IFN). From the lungs of animals harboring the hybrid construct, we isolated and characterized Clara cells. The cells contain dense secretory granules and mitochondria typical of Clara cells, and express SP-A, SP-B, SP-D, and the Clara cell secretory protein, CC10. Withdrawal of the IFN and elevation of the incubation temperature permit normal cell differentiation similar to that of Clara cells in vivo. This cell line should be very useful for the investigation of normal Clara cell function and gene expression.
克拉拉细胞被认为是外周气道上皮的祖细胞，它除了产生10 kDa的克拉拉细胞分泌蛋白（CCSP或CC10）外，还产生表面活性蛋白SP-A和SP-B。迄今为止，开发克拉拉细胞系的尝试均未成功。大多数此类尝试都涉及体外插入转化病毒癌基因。我们之前报道过从H-2Kb-tsA58转基因小鼠中获得的一种分化的条件永生化小鼠肺II型上皮细胞系T7的特性。我们还利用这个小鼠模型来获得克拉拉细胞系。在这个模型中，通过创建一个转基因来规避体外基因插入的需求，其中猿猴病毒40（SV40）温度敏感株（tsA58）的大肿瘤抗原与主要组织相容性复合体启动子H-2Kb融合。该启动子在多种组织中具有活性，并受干扰素（IFN）诱导。从携带杂交构建体的动物肺中，我们分离并鉴定了克拉拉细胞。这些细胞含有克拉拉细胞典型的致密分泌颗粒和线粒体，并表达SP-A、SP-B、SP-D和克拉拉细胞分泌蛋白CC10。去除干扰素并提高孵育温度可使细胞正常分化，类似于体内克拉拉细胞的分化。该细胞系对于研究正常克拉拉细胞功能和基因表达应该非常有用。
