Title:  NANBV diagnostics and vaccines

United States Patent:  6,346,375

Assignee:  Chiron Corporation (Emeryville, CA)

Filed:  March 14, 1995

We have discovered epitopes of the HCV viral proteins which are immunoreactive with immune serum. The epitopes are useful in immunodiagnostic assays and as immunogens.

DISCLOSURE OF THE INVENTION

The invention pertains to the isolation and characterization of a newly discovered etiologic agent of NANBH, hepatitis C virus (HCV), its nucleotide sequences, its protein sequences and resulting polynucleotides, polypeptides and antibodies derived therefrom. The inventions described herein were made possible by the discovery of cDNA replicas isolated by a technique which included a novel step of screening expression products from cDNA libraries created from a particulate agent in infected tissue with sera from patients with NANBH to detect newly synthesized antigens derived from the genome of the heretofore unisolated and uncharacterized viral agent, and of selecting clones which produced products which reacted immunologically only with sera from infected individuals as compared to non-infected individuals.

Studies of the nature of the genome of the HCV, utilizing probes derived from the HCV cDNA, as well as sequence information contained within the HCV cDNA, are suggestive that HCV is a positive-stranded RNA virus which appears to be distantly related to the flaviviridae family, and to the pestiviruses.

Portions of the cDNA sequences derived from HCV are useful as probes to diagnose the presence of virus in samples, and to isolate naturally occurring variants of the virus. These cDNAs also make available polypeptide sequences of HCV antigens encoded within the HCV genome(s) and permits the production of polypeptides which are useful as standards or reagents in diagnostic tests and/or as components of vaccines. Antibodies, including for example both polyclonal and monoclonal, directed against HCV epitopes contained within these polypeptide sequences are also useful for diagnostic tests, as therapeutic agents, for screening of antiviral agents, and for the isolation of the NANBV agent from which these cDNAs derive. In addition, by utilizing probes derived from these cDNAs it is possible to isolate and sequence other portions of the HCV genome, thus giving rise to additional probes and polypeptides which are useful in the diagnosis and/or treatment, both prophylactic and therapeutic, of NANBH.

Accordingly with respect to polynucleotides, some aspects of the invention are: a purified HCV polynucleotide; a recombinant HCV polynucleotide; a recombinant polynucleotide comprising a sequence derived from an HCV genome or from HCV cDNA; a recombinant polynucleotide encoding an epitope of HCV; a recombinant vector containing any of the above recombinant polynucleotides, and a host cell transformed with any of these vectors.

Other aspects of the invention are: a recombinant expression system comprising an open reading frame (ORF) of DNA derived from an HCV genome or from HCV cDNA, wherein the ORF is operably linked to a control sequence compatible with a desired host, a cell transformed with the recombinant expression system, and a polypeptide produced by the transformed cell.

Still other aspects of the invention are: purified HCV, a preparation of polypeptides from the purified HCV; a purified HCV polypeptide; a purified polypeptide comprising an epitope which is immunologically identifiable with an epitope contained in HCV.

Included aspects of the invention are a recombinant HCV polypeptide; a recombinant polypeptide comprised of a sequence derived from an HCV genome or from HCV cDNA; a recombinant polypeptide comprised of an HCV epitope; and a fusion polypeptide comprised of an HCV polypeptide.

Also included in the invention are a monoclonal antibody directed against an HCV epitope; and a purified preparation of polyclonal antibodies directed against an HCV epitope; and an anti-idiotype antibody comprising a region which mimics an HCV epitope.

Another aspect of the invention is a particle which is immunogenic against HCV infection comprising a non-HCV polypeptide having an amino acid sequence capable of forming a particle when said sequence is produced in a eukaryotic host, and an HCV epitope.

Still another aspect of the invention is a polynucleotide probe for HCV.

Aspects of the invention which pertain to kits are those for: analyzing samples for the presence of polynucleotides derived from HCV comprising a polynucleotide probe containing a nucleotide sequence from HCV of about 8 or more nucleotides, in a suitable container; analyzing samples for the presence of an HCV antigen comprising an antibody directed against the HCV antigen to be detected, in a suitable container; analyzing samples for the presence of an antibodies directed against an HCV antigen comprising a polypeptide containing an HCV epitope present in the HCV antigen, in a suitable container.

Other aspects of the invention are: a polypeptide comprising an HCV epitope, attached to a solid substrate; and an antibody to an HCV epitope, attached to a solid substrate.

Still other aspects of the invention are: a method for producing a polypeptide containing an HCV epitope comprising incubating host cells transformed with an expression vector containing a sequence encoding a polypeptide containing an HCV epitope under conditions which allow expression of said polypeptide; and a polypeptide containing an HCV epitope produced by this method.

The invention also includes a method for detecting HCV nucleic acids in a sample comprising reacting nucleic acids of the sample with a probe for an HCV polynucleotide under conditions which allow the formation of a polynucleotide duplex between the probe and the HCV nucleic acid from the sample; and detecting a polynucleotide duplex which contains the probe.

Still other aspects are also included in the invention. These include an immunoassay for detecting an HCV antigen comprising incubating a sample suspected of containing an HCV antigen with a probe antibody directed against the HCV antigen to be detected under conditions which allow the formation of an antigen-antibody complex; and detecting an antigen-antibody complex containing the probe antibody. An immunoassay for detecting antibodies directed against an HCV antigen comprising incubating a sample suspected of containing anti-HCV antibodies with a probe polypeptide which contains an epitope of the HCV, under conditions which allow the formation of an antibody-antigen complex; and detecting the antibody-antigen complex containing the probe antigen.

Also included in the invention are vaccines for treatment of HCV infection comprising an immunogenic peptide containing an HCV epitope, or an inactivated preparation of HCV, or an attenuated preparation of HCV.

Another aspect of the invention is a tissue culture grown cell infected with HCV.

Yet another aspect of the invention is a method for producing antibodies to HCV comprising administering to an individual an isolated immunogenic polypeptide containing an HCV epitope in an amount sufficient to produce an immune response.

Claim 1 of 9 Claims

What is claimed is:

1. An octamer polypeptide immunoreactive with an HCV antibody, wherein the octamer has the amino acid sequence shown at positions 2280 to 2287 (AA2280-AA2287) as set forth in FIG. 72 (SEQ ID NOS:137-138).

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