Development of immunological responsiveness and resistance to infection with Treponema pallidum in rabbits given immune lymphocyte preparations.

Three groups of normal rabbits were administered: 1. viable lymphocytic cells; 2. lysates of lymphocytes obtained by freezing and thawing, and 3. low molecular weight dialyzable transfer factor (TF). The lymphocytes were derived from peripheral blood, lymph nodes, and spleens of rabbits: 1. cured of longlasting syphilitic infection by penicillin treatment, and 2. immunized with nonviable T. pallidum, exhibiting a good reactivity by tests for humoral and cell-mediated responses. All the three lymphocyte preparations were found to be able to transfer cell-mediated response as measured by the Macrophage Migration Inhibition Test (MMI) and the Skin Test for Delayed Hypersenitivity to Treponemal Antigens (SDH), from a reactive donor to the nonreactive recipient rabbit; the intensity of the response found in the recipient was roughly the same as in the donor. None of the lymphocyte preparations transferred humoral response, as measured by the TPI and VDRL tests. Only whole lymphocytic cells were found to be able to confer a stat of resistance to infection with T. pallidum on normal recipients.