Development of a conditionally immortalized testicular Sertoli cell line RTS3-3 from adult transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen gene

Transgenic mice and rats harboring temperature-sensitive simian virus 40 (tsSV40) large T-antigen gene are useful for establishing cell lines from tissues. We succeeded in establishing a conditionally immortalized testicular Sertoli cell line, RT3-3, from adult transgenic rats harboring the oncogene. The cells grew at permissive (33 degrees C) and intermediate (37 degrees C) temperatures but not at nonpermissive temperature (39 degrees C). Large T-antigen was expressed at 33 and 37 degrees C, whereas the expression level was gradually decreased at 39 degrees C, suggesting that the temperature-sensitive growth characteristics arise as a result of the function of tsSV40 large T-antigen. The cells showed biochemical features associate with normal Sertoli cells including expressions of mRNAs of sulfated glycoprotein-2 (SGP-2), transferrin (TF) and steel factor. Quantitative polymerase chain reaction revealed that nonpermissive temperature induced increase in the level of SGP-2. Moreover, levels of SGP-2 and/or TF were significantly elevated in the cells treatment with sodium butyrate and retinoic acid, inducers of cellular differentiation. To our knowledge, this is the first report of the establishment of a testicular Sertoli cell line from the transgenic rats. Thus, the conditionally immortalized cell line RTS3-3 with unique characteristics may serve as good experimental in vitro models for basic and applied biology of testicular Sertoli cells.