Distribution of Virus-Like Particles in the Lymphatic Tissues of “Nonleukemic” CFW W Conventional Mice. ∗

Summary

A study was made on the “non-leukemic” conventional CFW_W mice which show a 29% incidence of spontaneous leukemia by 24 months of age. An estimate on the presence of virus particles in the thymus showed 61% with C type particles and 28% with A 2 particles. In addition, 22% of the spleens and 17% of the lymph nodes examined contained C type particles. The C type particles in the thymus were associated with epthelial cells while the A 2 particles were within lymphocytes. This particle concentration within certain cell types, as it may relate to sampling error, was discussed. The implication of the thymus as a source of virus was discussed, including the possible role of the thymic blood barrier and epithelial cells in the “release” of particles to other lymphatic tissues.