Viral Etiology of Mouse Leukemia

Abstract

Publisher Summary This chapter reviews the principal experimental findings referring to the viral etiology of mouse leukemia that have been accumulated during the preceding decade. Leukemia is a relatively rare disease in mice. Although exact data are not available, it is apparent that the natural incidence of spontaneous leukemia in a mixed population of mice is relatively low. However, figures are available only for mice of certain inbred strains. One of the principal factors responsible for the development of spontaneous leukemia in mice was genetic, and thus inherited from one generation to another. Among the nongenetic factors recognized to influence the incidence of spontaneous leukemia in mice were estrogenic hormones, removal of thymus, and restriction of caloric food intake. A relatively high incidence of leukemia or allied neoplasms can be induced with hormones, carcinogenic chemicals, or by total-body X-ray irradiation in mice of various strains, which, under normal conditions of life, remain essentially free from this disease when undisturbed. Transmission of spontaneous lymphatic mouse leukemia by filtrates succeeded when filtrates prepared from Ak mice with spontaneous lymphatic leukemia were inoculated into newborn mice of the low leukemic C3H strain. The chapter also discusses the natural epidemiology of the leukemic virus in mice. The inoculation of cell-free Ak leukemic extracts into newborn mice of the Ak strain greatly accelerated the development of spontaneous leukemia in such animals. The leukemic agent is a submicroscopic spherical particle which readily passes bacteria-tight filters. The leukemic virus was found to be relatively sensitive to moderate heating.