Abstract
Summary
The response of 1-day-old peritoneal macrophage cultures to inoculation with a standard dose of LDH virus, 106 ID50/ml, was consistent in all experiments; peak virus infectivity up to 109 ID50/ml was reached by 3 days followed by a decline to below the ID50 within 21 days. Cultures were not infected by doses of virus containing less than 103 ID50/ml. Since lymphocytes were shown not to be involved in the replicative process, and interferon could not be detected in the supernatant fluids of infected cultures, it is suggested that the decline in virus infectivity might be due to the combined effect of the exhaustion of a small number of susceptible cells and an age-dependent decrease in susceptibility of macrophage cultures.
The author expresses his appreciation to Dr. J⊘rgen Fogh, Sloan Kettering Institute for Cancer Research, Rye, New York, for use of his tissue culture facilities, and Dr. M. H. Salaman and Dr. C. Chester Stock for support and counsel. This work was partly supported by a block grant from the British Empire Cancer Campaign and by NCI Grant CA08748.
Get full access to this article
View all access options for this article.