Persistence of Viruses of Kuru and Creutzfeldt-Jakob Disease in Tissue Cultures of Brain Cells

THE viruses of the two spongiform viral encephalopathies of man, kuru and Creutzfeldt-Jakob disease, have been maintained in vitro in tissue cultures of brain cells for periods of more than 70 days and more than 250 days, respectively. Infectivity of long-maintained explant cultures of small brain fragments (and of trypsinized layers of brain cells) has been demonstrated by the transmission of the respective diseases to chimpanzees using combined intracerebral and peripheral inoculation of the frozen and thawed cultivated cells scraped from the cultivation surface into the culture medium 1,2 . Kuru was transmitted using an inoculum prepared from pooled brain cells from three chimpanzees with experimental kuru in third passage which were maintained as primary brain explants for 70, 215, and 238 days, respectively. Creutzfeldt-Jakob (C-J) disease was transmitted to two chimpanzees using inocula prepared from, respectively, brain cells grown in vitro for more than 8.5 months from a human patient and brain cells grown in vitro for 1 month from a chimpanzee with second passage of experimental C-J disease. Details of the inoculation and transmission are presented below. The techniques of explant cultivation of brain cells have been described previously 3 .