Using Retroviral Vectors to Express SV40 Tumor Antigens

Retroviral vectors for polyomavirus tumor antigens, including SV40 large and small tumor antigens (SVT), have been extensively utilized to study the function of these proteins in a wide range of cell types. Properties of retroviruses that make them particularly efficient vectors include the capacity for dual gene expression in a single vector under the control of a single promotor or separate promotors, and efficient, stable integration of viral genes into the target cell genome (1 ). In addition, most cell types have receptors for retroviral infection and vectors may be engineered to further enhance their broad host range (2 ). A common application well suited to retroviral vectors is the generation of immortalized cell lines from different tissues following expression of SVT. Conditional, temperature-sensitive mutants of SVT have been used extensively for this purpose. Studies utilizing retroviral vectors to express SVT in a variety of cell types are represented by the following selected references (3 -20 ).>