Crucell Holland B.v.

Introgene B.v.

Other

Frits Jacobus Fallaux

Abraham Bout

Domenico Valerio

Robert Cornelis Hoeben

Alex Jan Van Der Eb

Govert Johan Schouten

Govert Schoutten

Cells capable of at least, in part, complementing adenovirus an adenovirus defective in E2A function. Such cells include a nucleic acid-encoding adenovirus E2A or a functional part, derivative, temperature-sensitive mutation and/or analogue thereof, integrated into the cell's genome. Methods for producing an adenovirus particle/vector with a functional deletion of E2A are also disclosed. Such methods involve providing a cell with the functionally deleted adenovirus vector, culturing the cell, and harvesting viral particles. The functional deletion may comprise a deletion in E2A. The nucleic acid-encoding E2A in the cell's genome may lack sequence overlap with the vector, preventing formation of a replication-competent adenovirus or restoration of E2A function. The adenovirus vector may further include a functional deletion in the E1-region. Methods are disclosed for providing cells of an individual with a nucleic acid of interest, without risk of administering simultaneously a replication-competent adenovirus vector, comprising administering the individual an adenovirus vector described herein.

Means and methods for nucleic acid delivery vehicle design and nucleic acid transfer

Presented are ways to address the problem of replication competent adenovirus in adenoviral production for use with, for example, gene therapy. Packaging cells having no overlapping sequences with a selected vector are suited for large scale production of recombinant adenoviruses. A system for use with the invention produces replication defective adenovirus. The system includes a primary cell containing a nucleic acid based on or derived from adenovirus and an isolated recombinant nucleic acid molecule for transfer into the primary cell. The isolated recombinant nucleic acid molecule is based on or derived from an adenovirus, has at least one functional encapsidation signal and at least one functional Inverted Terminal Repeat, and lacks overlapping sequences with the nucleic acid of the cell. Otherwise, the overlapping sequences would enable homologous recombination leading to replication competent adenovirus in the primary cell into which the isolated recombinant nucleic acid molecule is to be transferred.

Packaging systems for human recombinant adenovirus to be used in gene therapy

Presented are ways to address the problem of replication competent adenovirus in adenoviral production for use with, for example, gene therapy. Packaging cells having no overlapping sequences with a selected vector are suited for large-scale production of recombinant adenoviruses. A system for use with the invention produces replication-defective adenovirus. The system includes a primary cell containing a nucleic acid based on or derived from adenovirus and an isolated recombinant nucleic acid molecule for transfer into the primary cell. The isolated recombinant nucleic acid molecule is based on or derived from an adenovirus, has at least one functional encapsidation signal and at least one functional Inverted Terminal Repeat, and lacks overlapping sequences with the nucleic acid of the cell. Otherwise, the overlapping sequences would enable homologous recombination leading to replication competent adenovirus in the primary cell into which the isolated recombinant nucleic acid molecule is to be transferred.

Presented are ways to address the problem of replication competent adenovirus in adenoviral production for use with, for example, gene therapy. Packaging cells having no overlapping sequences with a selected vector and are suited for large scale production of recombinant adenoviruses. A system for use with the invention produces adenovirus incapable of replicating. The system includes a primary cell containing a nucleic acid based on or derived from adenovirus and an isolated recombinant nucleic acid molecule for transfer into the primary cell. The isolated recombinant nucleic acid molecule is based on or derived from an adenovirus, and further has at least one functional encapsidating signal, and at least one functional Inverted Terminal Repeat. The isolated recombinant nucleic acid molecule lacks overlapping sequences with the nucleic acid of the cell. Otherwise, the overlapping sequences would enable homologous recombination leading to replication competent adenovirus in the primary cell into which the isolated recombinant nucleic acid molecule is to be transferred.

The problem of replication-competent adenovirus in virus production is solved in that we have developed packaging cells that have no overlapping sequences with a new basic vector and thus, are suited for safe large scale production of recombinant adenoviruses. One of the additional problems associated with the use of recombinant adenovirus vectors is the host-defense reaction against treatment with adenovirus. Another aspect of the invention involves screening recombinant adenovirus vector lots, especially those intended for clinical use, for the presence of adenovirus E1 sequences, as this will reveal replication-competent adenovirus, as well as revertant E1 adenoviruses. It is also an aspect of the present invention to molecularly characterize the revertants that are generated in the newer helper/vector combinations.

Cells capable of at least, in part, complementing adenovirus E2A function of an adenovirus defective in E2A function. Such cells include a nucleic acid encoding adenovirus E2A or a functional part, derivative and/or analogue thereof, integrated into the genome of the cell. Preferably, the cell has E2A nucleic acid derived from a temperature sensitive adenovirus such as adenovirus ts125. Methods for producing an adenovirus particle containing an adenovirus vector with a finctional deletion of E2A are also disclosed. Such a method involves providing a cell as previously described with the functionally deleted adenovirus vector, culturing the cell, and harvesting the virus particle. The functional deletion can comprise a deletion of at least part of the nucleic acid encoding E2A. In such a method, the nucleic acid encoding adenovirus E2A in the genome of the cell preferably has no sequence overlap with the vector which leads to replication competent adenovirus and/or to the formation of an adenovirus vector comprising E2A function. In the method, the adenovirus vector preferably further comprises a functional deletion of E1-region encoding nucleic acid. Adenovirus vectors comprising a functional deletion of adenovirus E2A, preferably a deletion of at least part of the nucleic acid encoding E2A are also disclosed. Preparations of adenovirus vector containing adenovirus particles wherein the adenovirus vector comprises a functional deletion of E2A are also disclosed. Such an adenovirus vector preferably further includes a deletion of nucleic acid encoding E1-region proteins, and may be free of adenovirus vectors comprising E2A function. Methods for providing cells of an individual with a nucleic acid of interest, without risk of administering simultaneously a replication competent adenovirus vector, comprising administering the individual one of the previously described preparations are also disclosed.

Presented are ways to address the problem of replication competent adenovirus in adenoviral production for use with, for example, gene therapy. Packaging cells having no overlapping sequences with a selected vector and are suited for large scale production of recombinant adenoviruses. A method of the invention produces adenovirus incapable of replicating. The method includes a primary cell containing a nucleic acid based on or derived from adenovirus and an isolated recombinant nucleic acid molecule for transfer into the primary cell. The isolated recombinant nucleic acid molecule is based on or derived from an adenovirus, and further has at least one functional encapsidating signal, and at least one functional Inverted Terminal Repeat. The isolated recombinant nucleic acid molecule lacks overlapping sequences with the nucleic acid of the cell. Otherwise, the overlapping sequences would enable homologous recombination leading to replication competent adenovirus in the primary cell into which the isolated recombinant nucleic acid molecule is to be transferred.

The problem of replication competent adenovirus in virus production is solved in that we have developed packaging cells that have no overlapping sequences with a new basic vector and, thus, are suited for safe large scale production of recombinant adenoviruses. One of the additional problems associated with the use of recombinant adenovirus vectors is the host-defense reaction against treatment with adenovirus. Another aspect of the invention involves screening recombinant adenovirus vector lots, especially those intended for clinical use, for the presence of adenovirus E1 sequences, as this will reveal replication competent adenovirus, as well as revertant E1 adenoviruses. It is also an aspect of the present invention to molecularly characterize the revertants that are generated in the newer helper/vector combinations.

Growing community of inventors

Leiderdorp, Netherlands

Frits Jacobus Fallaux