Title:  Antibodies specific for proteins having polyglutamine expansions

United States Patent:  6,291,652

Assignee:  The Regents of the University of California (Berkeley, CA)

Filed:  January 7, 2000

Antibodies, as well as binding fragments and mimetics thereof, that specifically bind to polyglutamine expansion containing proteins, e.g. mutant huntingtin protein, are provided. The subject binding agents, e.g. antibodies, fragments and mimetics thereof, etc., are characterized in that they bind to the target polyglutamine expansion containing protein in a manner that differs from the 1C2 antibody, e.g. in terms of affinity, avidity, and the like. Also provided are methods of screening compounds for polyglutamine expansion protein binding modulation activity, as well as pharmaceutical compositions of such agents. In addition, methods and devices for screening samples for the presence of polyglutamine expansion containing proteins, e.g. mutant huntingtin protein, are provided. Finally, nucleic acids encoding the subject antibodies and methods for their expression, including in therapeutic treatment protocols, are provided.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

Antibodies, as well as binding fragments and mimetics thereof (including intrabodies), that specifically bind to polyglutamine expansion containing proteins, e.g. mutant huntingtin protein, are provided. The subject binding agents, e.g. antibodies, fragments and mimetics thereof, etc., are characterized in that they bind to the polyglutamine expansion containing protein in a manner that differs from the 1C2 antibody, e.g. in terms of at least one of specificity, affinity and avidity. Also provided are methods of screening compounds for polyglutamine expansion protein binding modulation activity, as well as pharmaceutical compositions of such agents. In addition, methods and devices for screening samples for the presence of polyglutamine expansion containing proteins, e.g. mutant huntingtin protein, are provided. Finally, nucleic acids encoding the subject antibodies and methods for their expression, including in therapeutic treatment protocols, are provided.

Before the subject invention is further described, it is to be understood that the invention is not limited to the particular embodiments of the invention described below, as variations of the particular embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology employed is for the purpose of describing particular embodiments, and is not intended to be limiting. Instead, the scope of the present invention will be established by the appended claims.

In this specification and the appended claims, the singular forms "a," "an," and "the" include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs.

ANTIBODIES

As summarized above, antibodies that recognize proteins having polyglutamine expansions are provided. More specifically, antibody compositions containing one or more antibodies, usually a plurality of antibodies and more usually a large plurality of antibodies, which recognize proteins having polyglutamine expansions are provided. By "recognize" is meant that the antibodies bind to proteins having polyglutamine expansions. The subject antibodies are specific for proteins having polyglutamine expansions. As the subject antibodies are specific for proteins having polyglutamine expansions, they bind preferentially to polyglutamine expansion containing proteins, as compared to proteins that do not contain polyglutamine expansions. In many embodiments, the subject antibodies do not bind to any appreciable extent to proteins that do not contain a polyglutamine expansion.

The polyglutamine expansions of the proteins to which the antibodies of the subject invention bind are glutamine stretches of at least 35 glutamine residues, where the number of glutamine residues in the polyglutamine expansion domain of the proteins typically ranges from about 35 to 200, usually from about 35 to 175 and more usually from about 35 to 150. The polyglutamine expansion of the target protein may be a heteropolymer stretch or homopolymeric stretch. Where the polyglutamine expansion is a heteropolyglutamine expansion, the number of non-glutamine residues in the expansion is limited, where the number % of non-glutamine residues does not exceed about 10, usually does not exceed about 5 and more usually does not exceed about 3. In many embodiments, the polyglutamine expansion is a homopolyglutamine expansion, by which is meant that the polyglutamine expansion does not include any non-glutamine residues.

Generally, the polyglutamine expansion containing proteins recognized by the subject antibodies are proteins associated with disease conditions. Polyglutamine expansion containing proteins of interest that are associated with disease conditions include: mutant huntingtin protein, mutant androgen receptor and the like. The subject antibodies specifically recognize mutant huntingtin protein having a polyglutamine expansion of at least 35 residues in length, where the polyglutamine expansion typically ranges from about 35 to 200, usually from about 35 to 175 and more usually from about 35 to 150. As such, one embodiment of the subject invention provides antibodies that specifically recognize mutant huntingtin protein whose presence is associated with Huntington's disease.

The subject antibodies are further characterized in that they differ from the 1C2 antibody with respect to at least one of specificity, affinity and avidity for their target polyglutamine expansion containing protein, e.g. a mutant huntingtin protein having a polyglutamine expansion longer than about 35 glutamine residues in length. The 1C2 antibody is described in WO 97/17445. As the specificity of the subject antibodies differs from that of the 1C2 antibody, the subject antibodies do not bind to all of the same proteins to which the 1C2 antibody binds. For example, the 1C2 antibodies binds to the transcription factor, TATA-binding protein (TBP), in addition to mutant huntingtin protein, i.e. the 1C2 antibody cross-reacts with TBP as well as mutant huntingtin protein. In comparison to 1C2, the subject antibodies bind less with TBP, where the degree of decreased binding is at least about 2 fold, usually at least about 5 fold and more usually at least about 10 fold. As such, the specificity of the subject antibodies differs from the specificity of 1C2. In certain embodiments, the affinity of the subject antibodies for the target polyglutamine expansion containing protein, e.g. mutant huntingtin protein, differs from the affinity of 1C2 for the same protein, where the magnitude of the difference is typically at least about 2 fold, usually at least about 5 fold and more usually at least about 10 fold. The affinity of the subject antibodies for the polyglutamine expansion containing protein to which they specifically bind ranges from about 10⁷ to 10⁹ l/m usually from about 10⁸ to 10⁹ l/m. In certain embodiments, the avidity of the subject antibodies for a polyglutamine expansion containing protein differs from the avidity of the 1C2 antibody for the same protein. In these embodiments, the magnitude of the difference is typically at least about 2 fold, usually at least about 5 fold and more usually at least about 10 fold. As such, the subject antibodies differ from the 1C2 antibody with respect to at least one of specificity, affinity and avidity.

The subject antibody compositions may be polyclonal compositions, such that a heterogeneous population of antibodies differing by specificity is present in the composition, or monoclonal compositions, in which a homogeneous population of identical antibodies that have the same specificity for the target polyglutamine expansion containing protein are present. As such, both monoclonal and polyclonal antibodies are provided by the subject invention. In many preferred embodiments, the subject antibodies are monoclonal antibodies. Specific monoclonal antibodies of interest include: 1F11E5, 4H7H7, 3A2D3, 4F1B5, 3C4A6, 3B5H10, where hybridomas that produce these specific monoclonal antibodies are deposited with the American Type Culture Collection depository (10801 University Boulevard, Manassas, Va. 20110-2209) and have been assigned ATCC accession nos. PTA-2846, PTA-2847, PTA-2849, PTA-2851, PTA-2850, and PTA-2848, respectively.

Claim 1 of 22 Claims

What is claimed is:

1. A monoclonal antibody that recognizes a protein having a polyglutamine expansion, wherein the percentage of non-glutamine residues in said polyglutamine expansion does not exceed 10% and said antibody has greater mutant huntingtin protein binding affinity than a 1C2 monoclonal antibody.

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