Title:  Methods to inhibit replication of infective virus

United States Patent:  6,232,120

Assignee:  The Johns Hopkins University School of Medicine (Baltimore, MD)

Filed:  February 16, 1999

The present invention provides a conditionally replicating viral vector, methods of making, modifying, propagating and selectively packaging, and using such a vector, isolated molecules of specified nucleotide and amino acid sequences relevant to such vectors, a pharmaceutical composition and a host cell comprising such a vector, the use of such a host cell to screen drugs. The methods include the prophylactic and therapeutic treatment of viral infection, in particular HIV infection, and, thus, are also directed to viral vaccines and the treatment of cancer, in particular cancer of viral etiology. Other methods include the use of such conditionally replicating viral vectors in gene therapy and other applications.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a conditionally replicating viral vector, which is characterized by a capacity to replicate only in a host cell that is permissive for replication of the vector.

In one embodiment, the conditionally replicating viral vector comprises at least one nucleic acid sequence, the presence, transcription or translation of which confers to the vector in a replication-permissive host cell a selective advantage over a wild-type strain of virus corresponding to the virus from which the vector was derived.

In another embodiment of the conditionally replicating viral vector, the vector, which preferably is a retrovirus, comprises at least one nucleic acid sequence, the presence, transcription or translation of which confers to a host cell, which is infected with the vector, a selective advantage over a cell infected with a wild-type strain of virus corresponding to the virus from which the vector was derived.

Also provided by the present invention is a pharmaceutical composition comprising a conditionally replicating viral vector and a pharmaceutically acceptable carrier. Further provided is a host cell comprising a conditionally replicating viral vector. A vector, wherein said vector, if DNA, comprises a nucleotide sequence selected from the group consisting of SEQ ID NOS: 2, 3, 4, 5, 6, 14, in which at least one N is mutated, 15 and 16 and wherein said vector, if RNA, comprises a nucleotide sequence encoded by a nucleotide sequence selected from the group consisting of SEQ ID NOS: 2, 4, 5, 6, 7, 15, 16, 17 and 18 is also provided as are isolated and purified nucleic acid molecules as set forth herein. Similarly provided are a method of engendering a vector with a ribozyme, a method of modifying a vector, and a method of propagating and selectively packaging a conditionally replicating vector without using a packaging cell line.

In yet another embodiment of the present invention, a method of therapeutically and prophylactically treating a host cell for a viral infection is provided. Such methods can additionally comprise the use of a helper-expression vector, a cytotoxic drug, proteins/factors, or a protease/reverse transcriptase inhibitor as appropriate. The method can be used, for example, to inhibit replication of a virus, treat cancer, in vivo gene transfer, or to express a gene of interest in a host cell.

In still yet another embodiment, a method of using a host cell comprising a conditionally replicating vector to detect interaction between a drug/factor and a protein is provided. Such a method enables protein characterization and screening of drugs/factors for activity with respect to a given protein.

Claim 1 of 32 Claims

What is claimed is:

1. A method to inhibit the replication of an infective replicable human immunodeficiency virus (HIV) in a cell, which method comprises

contacting the cell, which is infected or at risk for being infected with said HIV, with a conditionally replicating human immunodeficiency viral vector which comprises at least a first nucleotide sequence, wherein said contacting occurs ex vivo or in vitro, and

wherein said first nucleotide sequence adversely affects said HIV; and

wherein the conditionally replicating human immunodeficiency viral vector replicates in a host cell only upon complementation with a wild-type virus or a helper virus, or a helper vector, and wherein said complementation renders the host cell permissive for replication of said conditionally replicating vector; and

wherein said vector is selectively replicated over said wild-type virus, helper virus, or helper vector.

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