I'm trying to understand why transduction of cells with a viral gene under its viral promoter yields a different phenotype than when the same gene and promoter are incorporated into a viral vector (HSV1 in this case).
Ex: Transducing cells to express an essential protein for HSV1 viral lifecycle (ICP4) vs just having a wildtype ICP4+ virus. If the cells transduced and expressing ICP4 dont rescue the virus what could the reason be? Aside from a shutdown of the trans gene expression. General or specific answers/speculations appreciated.