Abstract: Lentiviral vectors modified at the 5? LTR or both the 5? and 3? LTR's are useful in the production of recombinant lentivirus vectors. Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production.

Abstract: Lentiviral vectors modified at the 5? LTR or both the 5? and 3? LTR are useful in the production of recombinant lentivirus vectors (See the Figure). Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production. The vectors can contain inducible or conditional promoters.

Abstract: Lentiviral vectors modified at the 5? LTR or both the 5? and 3? LTR's are useful in the production of recombinant lentivirus vectors. Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging plasmids and packagable vector transcripts are produced from high expression plasmids after stable or transient transfection in mammalian cells. High titers of recombinant retrovirus are produced in these transfected mammalian cells and can then transduce a mammalian target cell by cocultivation or supernatant infection. The methods of the invention include the use of the novel retroviral packaging plasmids and vectors to transduce primary human cells, including T cells and human hematopoietic stem cells, with foreign genes by cocultivation or supernatant infection at high efficiencies. The invention is useful for the rapid production of high titer viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.

Abstract: Lentiviral vectors modified at the 5? LTR or both the 5? and 3? LTR's are useful in the production of recombinant lentivirus vectors. Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production.

Abstract: Lentiviral vectors modified at the 5? LTR or both the 5? and 3? LTR's are useful in the production of recombinant lentivirus vectors. Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging plasmids and packagable vector transcripts are produced from high expression plasmids after stable or transient transfection in mammalian cells. High titers of recombinant retrovirus are produced in these transfected mammalian cells and can then transduce a mammalian target cell by cocultivation or supernatant infection. The methods of the invention include the use of the novel retroviral packaging plasmids and vectors to transduce primary human cells, including T cells and human hematopoietic stem cells, with foreign genes by cocultivation or supernatant infection at high efficiencies. The invention is useful for the rapid production of high titer viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging plasmids and packagable vector transcripts are produced from high expression plasmids after stable or transient transfection in mammalian cells. High titers of recombinant retrovirus are produced in these transfected mammalian cells and can then transduce a mammalian target cell by cocultivation or supernatant infection. The methods of the invention include the use of the novel retroviral packaging plasmids and vectors to transduce primary human cells, including T cells and, human hematopoietic stem cells, with foreign genes by cocultivation or supernatant infection at high efficiencies. The invention is is useful for the rapid production of high titer viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.

Abstract: Lentiviral vectors modified at the 5′ LTR or both the 5′ and 3′ LTR's are useful in the production of recombinant lentivirus vectors. Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging plasmids and packagable vector transcripts are produced from high expression plasmids after stable or transient transfection in mammalian cells. High titers of recombinant retrovirus are produced in these transfected mammalian cells and can then transduce a mammalian target cell by cocultivation or supernatant infection. The methods of the invention include the use of the novel retroviral packaging plasmids and vectors to transduce primary human cells, including T cells and human hematopoietic stem cells, with foreign genes by cocultivation or supernatant infection at high efficiencies. The invention is useful for the rapid production of high titer viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.

Abstract: Lentiviral vectors modified at the 5′ LTR or both the 5′ and 3′ LTR's are useful in the production of recombinant lentivirus vectors. Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging plasmids and packagable vector transcripts are produced from high expression plasmids after stable or transient transfection in mammalian cells. High titers of recombinant retrovirus are produced in these transfected mammalian cells and can then transduce a mammalian target cell by cocultivation or supernatant infection. The methods of the invention include the use of the novel retroviral packaging plasmids and vectors to transduce primary human cells, including T cells and human hematopoietic stem cells, with foreign genes by cocultivation or supernatant infection at high efficiencies. The invention is useful for the rapid production of high titer viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.

Abstract: Lentiviral vectors modified at the 5' LTR or both the 5' and 3' LTR's are useful in the production of recombinant lentivirus vectors. Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging plasmids and packagable vector transcripts are produced from high expression plasmids after stable or transient transfection in mammalian cells. High titers of recombinant retrovirus are produced in these transfected mammalian cells and can then transduce a mammalian target cell by cocultivation or supernatant infection. The methods of the invention include the use of the novel retroviral packaging plasmids and vectors to transduce primary human cells, including T cells and human hematopoietic stem cells, with foreign genes by cocultivation or supernatant infection at high efficiencies. The invention is useful for the rapid production of high titer viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.

Abstract: Lentiviral vectors modified at the 5' LTR or both the 5' and 3' LTR's are useful in the production of recombinant lentivirus vectors. Such vectors can be produced in the absence of a functional tat gene. Multiple transformation of the host cell with the vector carrying the transgene enhances virus production.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging constructs and packagable vector transcripts are produced from high expression plasmids by transfection in human cells. High titers of recombinant retrovirus are produced in infected cells. The methods of the invention include the use of the novel retroviral constructs to transduce primary human cells, including T cells and human hematopoietic stem cells, with foreign genes by cocultivation at high efficiencies. The invention is useful for the rapid production of high viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging constructs and packagable vector transcripts are produced from high expression plasmids by transfection in human cells. High titers of recombinant retrovirus are produced in infected cells. The methods of the invention include the use of the novel retroviral constructs to transduce primary human cells, including T cells and bone marrow stem cells, with foreign genes by cocultivation at high efficiencies. The invention is useful for the rapid production of high viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.

Abstract: The invention provides a novel retroviral packaging system, in which retroviral packaging constructs and packagable vector transcripts are produced from high expression plasmids by transfection in human cells. High titers of recombinant retrovirus are produced in infected cells. The methods of the invention include the use of the novel retroviral constructs to transduce primary human cells, including T cells and human hematopoietic stem cells, with foreign genes by cocultivation at high efficiencies. The invention is useful for the rapid production of high viral supernatants, and to transduce with high efficiency cells that are refractory to transduction by conventional means.