Prions are the causative agents of some rapidly progressive neurodegenerative diseases known as transmissible spongiform encephalopathies or prion diseases. These are infectious isoforms of a host-encoded cellular protein known as prion protein. Prion diseases affect humans and animals and are uniformly fatal in nature. [1]Structure of PrionsPrions are small infectious particles composed of abnormally folded proteins that cause progressive neurodegenerative conditions. [2] Prions: the term was coined in 1982 by Stanley B. Prusiner, who was among others who postulated their existence. A prion particle is composed of one or more amyloid fibers or oligomers, which are further composed of prion proteins. [2] Research shows that prions are resistant to heat, radiation, and chemical action.[3] In 1995, researchers Byron Caughey of the National Institute of Allergy and Infectious Diseases and Peter Lansbury of Brigham and Women's Hospital discovered an analogy of Vonnegut's ice-nine and prion structure. [2] The infectious particles that spread prion disease: Scrapie consisted of highly stable crystals of a normally harmless material found in the brains of sheep. [2] Crystalline clumps of this misfolded version of the protein convince other molecules of the same protein to fold into the aberrant conformation. The process continues until virtually all of the protein in a cell or tissue has been converted into prions. [2,3] Prion proteins have the ability to recruit other proteins of the same sequence as they grow into a well-organized lattice structure. When a new monomer arrives, it binds to the fibril and takes on the exact shape of its neighbor. The fibrils can eventually clump together to...... middle of paper ...... a particular protein, called MAVS, which is critical to our innate ability to fight some viral infections, acquires a self-perpetuating fibrillar shape in cells that have been infected by the virus and amplifies the cellular alarm signal. [7] This ultimately induces the production of interferons that recruit macrophages to fight the infection. [7]Prions: still a mystery Associated with numerous neurological diseases, prions or misfolded proteins can also play a decisive role in normal cellular functioning. [2] Much research has been conducted on prion biology, but many questions still remain unanswered, such as how PrPC is converted to PrPSc; how prions move from one host to another; how the symptoms of the disease emerge; normal physiological functions of PrP. [6] Future studies on the prion protein will pave the way for the treatment of other neurodegenerative disorders as well.