Murine transfer factors: dose-response relationships and routes of administration.

Transfer factors are protein immunomodulators that transfer the ability to express cell-mediated immunity from immunized donors to nonimmune recipients. The effects are antigen-specific. The experiments described in this report are a comparison of the relationship of the route of administration of various transfer factors to the magnitude of the delayed hypersensitivity responses (footpad swelling) to the corresponding antigen in the recipients. Three doses of each of four affinity-purified transfer factor preparations were studied. There were no significant differences in the footpad responses by recipients of either oral or subcutaneous transfer factor. These results support proposals for oral administration of transfer factors in clinical trials.