Abstract: Method of stimulating an immune response (e.g., to treat cancer) include administering to a subject a composition including dendritic cells incubated with (i) oHSV-infected tumor cells or a composition derived therefrom, or (ii) tumor cells plus oHSV, as well as methods of preparing such compositions, are described.

Abstract: Method of stimulating an immune response (e.g., to treat cancer) include administering to a subject a composition including dendritic cells incubated with (i) oHSV-infected tumor cells or a composition derived therefrom, or (ii) tumor cells plus oHSV, as well as methods of preparing such compositions, are described.

Abstract: Improved methods for making non-cytotoxic helper virus-free preparations of herpes virus amplicon vectors or particles, the vectors themselves, recombinant helper virus and cells and methods of using same to treat patients and as tools in therapy and prevention, immunology, molecular biology, biotechnology and genetic engineering. In one embodiment, an amplicon plasmid vector contains at least one transgene that encodes a transgene product which is an interfering RNA molecule that can be converted into a siRNA by the cell machinery.

Abstract: A defective Cre-loxP based helper virus (HSV-1 LaL&Dgr;J), which genome is of reduced size and is free of the genes encoding ICP4 and ICP34.5 proteins from the helper genome, in addition to the native “a” signals. HSV-1 LaL&Dgr;J carries a single floxed “a” signal in gC locus. To produce HSV-1 LaL&Dgr;J and to prepare the amplicon vectors, two novel cell lines expressing the essential ICP4 protein, either alone or in combination to Cre recombinase, are also disclosed. These cell lines complement ICP4 while minimizing the probability of generating replication-competent particles. The novel helper system enables production of large amounts of high-titer amplicon vectors. Residual helper particles generated do not exceed 0.5% of the viral population and can grow only in cells expressing ICP4. Amplicon vectors produced with this method showed no cytotoxicity for infected cells.