Virologist D. Carleton Gajdusek, who was awarded the 1976 Nobel Prize in medicine for unraveling the nature of the prion disease Kuru, has died, as reported by the New York Times.
Gajdusek’s work on Kuru, a fatal encephalopathy found in the Fore people of New Guinea, proved that human transmissible spongiform encephalopathies (TSEs) could be transmitted among humans. This group of rare, slow diseases now includes Creutzfeldt-Jakob disease, Gerstmann-Straussler syndrome in humans, as well as bovine spongiform encephalopathy (BSE, or mad cow disease) and scrapie in sheep and goats. These disorders are rare, but always fatal. Gajdusek’s contribution was to understand that the fatal encephalopathy affecting the Fore people was spread among women and children by ritual cannibalism of the brains of deceased relatives. The disease stopped when cannibalism was discontinued.
Subsequent work by others showed that the infectious agents of TSEs are highly unconventional because they lack nucleic acid genomes. Stanley Prusiner called the agent of scrapie a ‘prion’ and suggested that an misfolded form of the protein causes the fatal encephalopathy. The genomes of many animals, including humans, carry a gene called prnp (encoding the PrP protein) which is essential for the pathogenesis of TSEs. In the simplest case, the misfolded PrP protein (PrPsc) converts normal PrP protein to more copies of the pathogenic form. The altered protein may be acquired by infection, by inheritance of the prnp gene with an autosomal mutation, or sporadically. It is believed that Kuru was established in the small Fore population when the brain of an individual with sporadic CJD was eaten.
I met Dr. Gajdusek briefly in the 1980s when he presented a seminar at Columbia. We were in a room alone for about 5 minutes, awaiting the arrival of other participants in the post-seminar dinner. In that short time it became clear that he was extremely intelligent, but not at all interested in my work on poliovirus, much to my disappointment.