Prions are the causative agents of a few rapidly progressive neurodegenerative diseases known as transmissible spongiform encephalopathies or prion diseases. These are infectious isoforms of a host-encoded cellular protein known as the prion protein. Prion diseases affect humans and animals and are uniformly fatal. [1]Structure of prionsPrions are small infectious particles composed of abnormally folded proteins that cause progressive neurodegenerative diseases. [2] Pray – the term was coined in 1982 by Stanley B. Prusiner, who was among others to postulate their existence. A prion particle is composed of one or more amyloid or oligomeric fibers, which are further composed of prion proteins. [2] Research shows that prions are resistant to heat, radiation and chemical action. [3] In 1995, investigators 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 the structure of prions. [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] Crystal clusters of this misfolded version of the protein cause other molecules of the same protein to fold into the aberrant conformation. The process continues until virtually all proteins in a cell or tissue are converted to prions. [2,3] Prion proteins have the ability to recruit other proteins of the same sequence as they develop into a well-organized network structure. When a new monomer arrives, it binds to the fibril and takes the exact shape of its neighbor. The fibrils can eventually bundle together to...... middle of paper ...... The particular protein, called MAVS, which is key to our innate ability to fight certain viral infections, acquires a self-sustaining fibrillar form in virus-infected cells and amplifies the cellular alarm signal. [7] This ultimately induces the production of interferons which recruit macrophages to fight the infection. [7] Prions: still a mystery Associated with many neurological diseases, prions or misfolded proteins can also play a determining role in normal cellular functioning. [2] Much research has been conducted on prion biology, but many questions remain unanswered, such as how PrPC is converted to PrPSc; how prions move from one host to another; how they bring out the symptoms of the disease; normal physiological functions of PrP. [6] Future studies of the prion protein will also pave the way for the treatment of other neurodegenerative disorders..