Provided are novel vectors and viral vectors capable of expressing exogenous gene or exogenous nucleic acid sequences in a target cell of interest, such as T cells, bone marrow cells, epithelial cells, liver cells and the like. The nucleic acid components of the vectors may include one or more native promoter/enhancer regions having modified sequence segments, one or more non-native promoter/enhancer or non-native promoter's gene or gene segment, and a native viral vector terminator or processing signal or segment thereof. The viral vectors comprise a virus or viral portion having on the surfaces or envelopes adsorption components, one for a packaging cell line and the other for delivery to a target cell. Packaging cell lines for propagating the vectors and viral vectors are also provided, as are novel processes for propagating any of the disclosed vectors or viral vectors.