Expression of human argininosuccinate synthetase in murine hematopoietic cells in vivo

As part of an effort to develop a model system for somatic gene therapy, a human argininosuccinate synthetase (AS) cDNA has been introduced into two gag⁺ retroviral vectors, and high titer clones were obtained for both constructs. The presence of proviral DNA sequences was detected in individual spleen colonies after infection of primary murine marrow cells with each virus. Mice were reconstituted for long-term survival with marrow infected with one virus, and they demonstrated elevated levels of AS expression in peripheral blood for up to eight weeks posttransplantation.