Failure of Thymopoietin, Ubiquitin and Synthetic Serum Thymic Factor to Restore Immunocompetence in T-Cell Deficient Mice

Abstract Thymopoietin, ubiquitin, and serum thymic factor, all of which induce T cell markers on lymphocytes, have been evaluated for their capacity to induce thymus-de-pendent activities in vivo. Multiple treatments over a period of weeks failed to restore either resistance to line lb leukemia or responses to T cell mitogens in T cell-deficient C58 mice. The findings suggest that these substances are ineffective in inducing thymus-dependent im-munocompetence that is meaningful in the intact animal.