Abstract: The present invention provides cell fusogenic vectors having replicative ability, whose protease-dependent tropism has been modified. M gene-deficient viral vectors encoding modified F proteins, in which the cleavage site of the F protein of paramyxovirus is modified to be cleaved by different proteases, were produced. In cells transfected with these vectors, the genomic RNA present in the vectors is replicated, and cell fusogenic infection spreads to neighboring cells depending on the presence of other proteases; however, no viral particles are released. The vectors of this invention, encoding the F proteins which are cleaved by proteases whose activity is enhanced in cancer, show cancer growth suppressive effect in vivo.

Abstract: Highly efficient gene transfer into primate-derived embryonic stem (ES) cells has successfully been achieved by using a simian immunodeficiency virus vector (SIV) pseudotyped with VSV-G protein, which is a surface glycoprotein of vesicular stomatitis virus (VSV) The present invention provides simian immunodeficiency virus vectors for gene transfer to primate ES cells. The method for gene transfer to primate ES cells using the vectors of the present invention is useful in, for example, research into embryology and disease, clinical applications, and experimental models for primates. The method is also useful in assaying and screening for genes and reagents able to enhance the specific differentiation of tissues or cells, and which are useful in preparing desired cells or tissues differentiated from ES cells.

Abstract: The present invention provides a retroviral vector containing a membrane protein having a hemagglutinin activity. The present inventors constructed a retroviral vector pseudotyped by the membrane protein having a hemagglutinin activity. This viral vector showed gene transfer at a high efficiency into host cells. In particular, it was established that genes can be transferred thereby at a high efficiency into cells into which genes can hardly be transferred by the conventional techniques, for example, blood cells and hematopoietic cells including hematopoietic stem cells, and mucous cells including mucosa epithelial cells. The viral vector of the present invention is highly useful as a vector for gene therapy.

Abstract: F gene-deficient virus virions are successfully recovered by using an F gene-deficient Sendai virus genomic cDNA. Further, F gene-deficient infectious viral particles are successfully constructed by using F-expressing cells as helper cells. Also, F gene and HN gene-deficient virus virions are successfully recovered by using a virus genomic cDNA deficient in both F gene and HN gene. Further, F gene and HN gene-deficient infectious viral particles are successfully produced by using F- and HN-expressing cells as helper cells. A virus deficient in F gene and HN gene and having F protein is constructed by using F-expressing cells as helper cells. In addition, M gene-deficient infectious virus particles were produced using helper cells expressing M protein. From cells infected with M gene-deficient viruses, release of virus-like particles was inhibited. Further, a VSV-G pseudo type virus is successfully constructed by using VSV-G-expressing cells.

Abstract: Selective amplification of cells is enabled by introducing into cells a gene encoding a fusion protein comprising (a) a ligand-binding domain, (b) a domain that associates when the ligand binds to the domain of (a), and (c) a domain that imparts proliferation activity to the cells upon the association and stimulating the cells with the ligand.

Abstract: A functional RNP containing negative-strand single-stranded RNA derived from Sendai virus, which has been modified so as not to express at least one envelope protein, has been successfully prepared. An RNP comprising a foreign gene is prepared and inserted into a cell with the use of a cationic liposome, thereby successfully expressing the foreign gene.

Abstract: A functional RNP containing negative-strand single-stranded RNA derived from Sendai virus, which has been modified so as not to express any envelope protein, has been successfully prepared. An RNP comprising a foreign gene is prepared and inserted into a cell with the use of a cationic liposome, thereby successfully expressing the foreign gene.

Abstract: F gene-deficient virus virions are successfully recovered by using an f gene-deficient Sendai virus genomic cDNA. Further, F gene-deficient infectious viral particles are successfully constructed by using F-expressing cells as helper cells. Also, F gene and HN gene-deficient virus virions are successfully recovered by using a virus genomic cDNA deficient in both F gene and HN gene. Further, F gene and HN gene-deficient infectious viral particles are successfully produced by using F- and HN-expressing cells as helper cells. A virus deficient in F gene and HN gene and having F protein is constructed by using F-expressing cells as helper cells. In addition, M gene-deficient infectious virus particles were produced using helper cells expressing M protein. From cells infected with M gene-deficient viruses, release of virus-like particles was inhibited. Further, a VSV-G pseudo type virus is successfully constructed by using VSV-G-expressing cells.

Abstract: Selective amplification of cells is enabled by introducing into cells a gene encoding a fusion protein comprising (a) a ligand-binding domain, (b) a domain that associates when the ligand binds to the domain of (a), and (c) a domain that imparts proliferation activity to the cells upon the association and stimulating the cells with the ligand.

Abstract: Selective amplification of cells is enabled by introducing into cells a gene encoding a fusion protein comprising (a) a ligand-binding domain, (b) a domain that associates when the ligand binds to the domain of (a), and (c) a domain that imparts proliferation activity to the cells upon the association and stimulating the cells with the ligand.