The subject invention concerns materials and methods for treating neurodegenerative diseases and conditions associated with aggregation of the microtubule-associated protein tau. A method of the invention comprises administering an effective amount of a heat shock protein 27 (Hsp27), or a biologically-active fragment or variant thereof, or a polynucleotide encoding the same, to a person or animal in need of treatment. In one embodiment, a heat shock protein 27 (Hsp27), or a biologically-active fragment or variant thereof, is contacted with or provided to a target cell. The target cell can be a neuron. In a specific embodiment, an Hsp27 is delivered to the target cell via a polynucleotide encoding an Hsp27 protein, or a biologically-active fragment or variant thereof. In one embodiment, a method of the invention comprises injecting (e.g., via stereotaxic injection) a polynucleotide expression construct of the invention comprising a polynucleotide encoding an Hsp27 protein directly into neural tissue of a person or animal. The subject invention also concerns compositions comprising i) a heat shock protein 27, or a biologically-active fragment or variant thereof, and/or ii) a polynucleotide encoding an Hsp27, or a biologically-active fragment or variant thereof. The polynucleotide can be an expression construct that provides for expression of an Hsp27 in a target cell.Cette invention concerne des matériaux et des méthodes pour traiter les maladies et les affections neurodégénératives dues à l'agrégation de la protéine tau associée à des microtubules. Une méthode selon l'invention comprend l'administration d'une quantité efficace d'une protéine de choc thermique 27 (Hsp27), ou d'un fragment ou variant biologiquement actif de celle-ci, ou d'un polynucléotide codant pour celle-ci, à une personne ou un animal ayant besoin d'être traité. Dans un mode de réalisation, une protéine de choc thermique 27 (Hsp27), ou un fragment ou variant biologiquement actif de celle-ci, est mi
