Replication-competent recombinant rhabdoviruses that lack a functional glycoprotein gene and express at least one foreign polypeptide such as a celluar receptor for another virus in their viral envelopes are useful in the treatment of pathogenic viruses. In one embodiment, a recombinant vesicular stomatitis virus (VSV) lacking its glycoprotein (G) gene and expressing instead the HIV receptor and a coreceptor is employed in a method for treating persons infected with HIV. The recombinant virus is defective for entry into normal cells but is able to control HIV infection in a T cell line by replicating in, and killing, HIV-infected cells.
Inventors:  Rose; John K. (Guilford, CT); Schnell; Matthias (Harleysville, PA); Johnson; E. Erik (New Haven, CT)

SUMMARY OF THE INVENTION

It is an objective of the invention to utilize this strategy to engineer recombinant viruses that can be employed to target cells infected with another virus such as HIV.

It is a further and more specific objective to provide a method for treating a person infected with HIV.

These and other objectives are accomplished by the present invention, which provides replication-competent recombinant rhabdoviruses such as vesicular stomatitis viruses (VSV) that lack a functional glycoprotein gene and express in their viral coats at least one foreign polypeptide. In preferred embodiments, the foreign polypeptide is a cellular receptor for another virus and is expressed in a manner sufficient to target cells infected with the other virus. In one embodiment, the invention provides replication-competent recombinant vesicular stomatitis virus which lacks a functional G glycoprotein gene and displays at least one cellular receptor for a pathogenic mammalian virus. Where the other virus is HIV, the expressed polypeptide is an HIV receptor such as CD4, an HIV coreceptor such as CXCR4, and/or mixtures of these.

The invention correspondingly provides methods for treating patients infected with a pathogenic virus by administering to the patient an effective amount of a recombinant rhabdovirus of the invention such as VSV which expresses in its viral envelope at least one receptor for the pathogenic virus. As set out hereafter, treatment methods for patients infected with HIV-1 and/or HIV-2 are disclosed.

DETAILED DESCRIPTION OF THE INVENTION

This invention is based upon the construction of a new virus from vesicular stomatitis virus (VSV) that is replication-competent and kills cells rapidly, but is only able to infect cells that are first infected with HIV. The virus contains a deletion in the VSV envelope glycoprotein gene and expresses instead the genes for the HIV receptor CD4 and an HIV coreceptor, CXCR4. The virus kills HIV-infected cells in culture and controls HIV infection.

In the practice of this invention, replication-competent recombinant rhabdoviruses are generated which lack a functional glycoprotein gene and express a foreign polypeptide in their viral envelopes. By "foreign" is meant not naturally occurring in the rhabdovirus transformed. The foreign polypeptide is one that binds to a mammalian cell such as a cellular receptor and/or coreceptor for another virus in many embodiments, and an antibody in other embodiments. The invention is particularly suited to target cells infected with membrame-enveloped viruses. The invention provides a general strategy of virus targeting to infected cells in cases where receptor(s) recognized by viral envelope proteins are known, and the viral protein has membrane fusion activity. Likewise, both conventional and hybrid antibodies to pathologic cells are also known and are used to target these cells. In either case, foreign polypeptides are expressed in the rhabdovirus in a manner sufficient to target cells to be killed. Therefore, as used herein, by a "recombinant rhabdovirus lacking a functional glycoprotein gene" is meant a virus having any alteration or disruption of the glycoprotein gene, and/or expressing a poorly functional or nonfunctional glycoprotein, or combinations thereof.

In the examples that follow, recombinant VSVs are generated which lack a functional envelope glycoprotein G or corresponding gene and express instead at least one receptor or coreceptor of an HIV virus. In preferred embodiments, the G gene is deleted, but any mutation of the gene that alters the host range specificity of VSV or otherwise eliminates the function of the G protein can be employed.

A gene for a foreign polypeptide such as one that binds to mammalian cells infected with a pathogenic virus is then inserted and/or added to the genome of the recombinant rhabdovirus. As summarized above, in many typical embodiments, the added gene is a receptor recognized by a virus glycoprotein and that is present on the surface of mammalian cells. However, recombinant rhabdoviruses engineered to kill other cells, e.g., cancer cells, are encompassed by the invention. In these embodiments, genes for specific antibodies and a membrane fusion protein are typically incorporated into rhabdoviruses lacking the a functional glycoprotein gene.

The invention thus provides medical or veterinary methods for treating a patient (human being or animal) infected with a pathogenic mammalian virus by administration to the patient of an effective amount of a replication-competent recombinant vesicular stomatitis virus which lacks a functional G glycoprotein gene and displays a receptor of the pathogenic virus in its coat in a manner sufficient to target cells infected with the pathogenic virus. An example wherein the pathogenic, membrane-enveloped virus is HIV and the envelope proteins added to the VSV are an HIV receptor and a specific coreceptor is given in the Examples section hereafter. In that illustration, a T cell tropic HIV is employed, but recombinant VSVs of the invention can been engineered to express coreceptors of other HIV strains. Other embodiments express a receptor and not a coreceptor, and some recombinant VSVs of the invention express more than one HIV coreceptor.

In the practice of a preferred embodiment of the invention, a patient infected with HIV is treated by administering to the patient an effective amount of a replication-competent recombinant vesicular stomatitis virus which lacks a functional glycoprotein G gene and expresses at least one HIV receptor such as CD4 and at least one HIV coreceptor such as CXCR4, CCR5, CCR3, and/or mixtures thereof. An exemplary construct is VSV.DELTA.G-CC4 described hereafter and illustrated in FIG. 1.

Administration of a recombinant rhabdovirus of the invention to a person or other mammal can be via any local or systemic method known by skilled workers, but is preferably systemic. Systemic administration includes intravenous, intramuscular, or intradermal administration by sterile injections, parenteral administration, and the like, typically in combination with a pharmaceutically acceptable carrier and/or other adjuvant or adjunct compound that maintains viability of the recombinant VSV virus or other rhabdovirus, or enhances its effect. Combinations of therapies may also be employed.

The amount of recombinant rhabdovirus necessary to bring about therapeutic treatment is not fixed per se, and necessarily depends upon the severity or the extent of disease. Administration is facilitated and, in some cases additional therapeutic effects are provided by, the carrier. When a carrier is employed, it is necessary that it be inert in the sense of not inactivating the recombinant VSV or other rhabdovirus and in the sense of not bringing about any adverse effect to the patient to which it is administered. In most situations, doses are dependent upon the extent of the patient's disease, the age, weight, and clinical condition of the patient to be treated, the potency of the recombinant virus, the adjuvants or adjunct compounds (if any) employed, and the concentrations of recombinant rhabdovirus and other ingredients which are typically put together in association with a pharmaceutically acceptable carrier. Most preferably, administration of the recombinant rhabdoviruses of the invention reduces the diseased cells in the patient so signficantly that they are barely detectable or undectable.

It is an advantage of the invention that preferred recombinant VSVs which incorporate the receptor of one virus in the coat of another kill cells infected with the other virus rapidly and thus control infection. It is a further advantage of the invention that recombinant VSVs or other rhabdoviruses of the invention are genetically engineered to specific targets, and kill only infected or pathogenic cells.
 

Claim 1 of 9 Claims

1. A replication-competent recombinant rhabdovirus whose genome lacks a functional rhabdoviral glycoprotein G gene and encodes at least one foreign polypeptide such that the foreign polypeptide is expressed in the viral envelope of said recombinant rhabdovirus.

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