Restricting expression prolongs expression of foreign genes introduced into animals by retroviruses

If foreign genes are ubiquitously expressed in mice using a viral vector, e xpression is abrogated by CD8(+) cells in 2 to 4 weeks. However, if the exp ression of the genes is confined to skeletal muscle cells, the CD8(+) T-cel l response is much weaker and expression is maintained for more than 6 week s. These data show that restricting the expression of foreign genes to skel etal muscle cells and presumably to other cells that are inefficient at ant igen presentation can prolong the expression of a foreign gene product.