Adenovirus facilitated infection of XXXX cells with ecotropic retrovirus.

@entity1 @entity19 @entity281 @entity1778 @entity9953 @entity8669
@entity281 is restricted by the expression of a viral receptor on the surface of the target cell. Retrovirus-mediated gene transfer is therefore not possible in cells that fail to express sufficient levels of the appropriate receptor, representing one major obstacle to the use of recombinant retroviruses in experimental and clinical applications. In this study, we utilized an adenoviral vector to express transiently the receptor for the ecotropic @entity19 @entity1778 virus in a panel of @entity1 cell lines. Following @entity281 , the susceptibility to ecotropic retroviral particles of A549, HeLa, RC39 and Meso 33 cells, derived from @entity1 lung epithelium, cervical epithelium, kidney and mesothelium, respectively, was measured on a single-cell basis by the detection of a cell surface marker encoded by the recombinant retrovirus. The marker, termed @entity9953 , was found in 10-30%, 25-50% and 50-90% of cells infected at 5, 50 and 250 adenovirus multiplicity of infection, respectively. Southern blot analysis demonstrated the integration of intact retroviral DNA. The integrated vector copy number increased with the adenoviral multiplicity of infection, suggesting that @entity8669 is proportional to receptor expression by the target cell, albeit not in a linear fashion. Susceptibility to ecotropic @entity281 was maintained undiminished for at least 3 days, indicating the persistent expression of ecotropic receptor by the adenovirus-transduced cells in that time period and the lack of a major cellular defense triggered by adenovirus infection against the subsequent @entity281 . Thus, the infection of @entity1 cells of various tissues with a recombinant adenovirus expressing the ecotropic @entity19 @entity1778 virus receptor generates a window of susceptibility where a high @entity281 rate can be achieved. Increased efficiency of @entity281 obtained in this fashion is amenable to specific regulation via the controlled expression of the adenovirus-encoded retroviral receptor.
