Immunologic Competence and Induction of Neoplasms by Polyoma Virus

Abstract

Summary

Thymectomy at 3 days of age in several inbred strains of mice and in an F₁ hybrid resulted in a strikingly increased frequency of neoplasms following infection with polyoma virus. Age susceptibility was extended to at least 30 days of age in highly resistant C57BL mice. The usual stigmata associated with thymectomy at birth were not found in the 3-day thymectomized mice. Nonetheless the methods used to restore immunologically deficient thymectomized neonates were also effective in restoring the capacity to resist polyoma virus tumor induction: adult syngeneic spleen cells, thymus tissue in Millipore diffusion chambers and syngeneic thymus grafts. Growth curves of polyoma virus in kidney, salivary glands and liver were quite similar in thymectomized and intact litter mates. Hemagglutination-inhibition antibodies determined periodically up to 30 days after infection were also similar in both groups. These results are discussed in terms of a concept involving virus-specific “tumor” antigens and the immunologic status of the animal.