Persistent Infection of Human Carcinoma and Primary Chick Embryo Cell Cultures with Simian Virus 40

Abstract

Summary

Continued multiplication of SV-40 has been demonstrated in 2 continuous lines of human cancer cells, in HeLa for approximately 8 months and in HEp-2 cells for a period of 6 months. Infection of the HeLa cells and to a lesser extent the HEp-2 cells was accompanied by changes in the gross appearance of the cultures depending upon the concentration of SV-40 in the inocula. The concentration of SV-40 in the fluid from the human cell cultures was high and neoplasms were induced in hamsters by fluid from 2 different cultures. SV-40 was also shed into the nutrient fluid of CE cultures kept for 6 months. The infectivity titers were low as determined in CMK and hamsters injected with fluid from a 91-day-old infected CE culture failed to develop neoplasms within a 160-day period. It was determined that approximately 10^5.5 ID₅₀ virus was necessary to induce neoplasms in hamsters within a period of 215 days.