Antibodies and intrabodies against huntingtin: production and screening of monoclonals and single-chain recombinant forms.

Antibodies can be extremely useful tools for the field of triplet repeats diseases. These reagents are important for localizing proteins in tissues and they can be used in the isolation and characterization of the components of protein complexes. In the context of huntingtin (Htt), antibodies can distinguish Htt with normal or an expanded polyglutamine (polyQ) repeats, and they can identify distinct conformations of Htt. Htt is the protein that, when mutated to contain an expanded polyQ motif, causes Huntington's disease (HD). Our group has produced monoclonal and recombinant single-chain antibodies (intrabodies) that can be used for these purposes and to perturb the function of Htt in living cells. Studies with anti-Htt intrabodies have led to identification of novel pathogenic epitopes. Moreover, some of the isolated intrabodies can reduce the neurotoxicity of mutant Htt in cell culture and animal models of HD. Thus, the production of antibodies and intrabodies has made a significant contribution to the understanding of HD pathogenesis and has introduced a novel strategy to treat this debilitating neurodegenerative disorder.