Adoptive Immunity to Intracellular Infection

Abstract

Cells of spleen and lymph node transferred specific immunity to Besnoitia jellisoni and Toxoplasma gondii, both obligate intracellular protozoa. Between isogeneic hamsters, direct transfer was effective. For allogeneic transfer it was necessary to use irradiated or tolerant hamsters as recipients. The bone marrow, thymus, liver and kidney cells of the immune donors were ineffective, as were lysed lymphoid cells, or intact lymphoid cells from immune donors that had been irradiated. Antiserum showed a slight protective effect, and increased the amount of immunity transferred by cells. Nevertheless, antibody did not appear to account for the transfer of immunity, as cell effects were dependent on cell survival and were not abolished by washing, trypsinization or treatment with rabbit-anti-hamster serum. Cells from heterospecifically immunized hamsters were ineffective by themselves and were not potentiated by specific antiserum. Both clinical immunity and transferable cellular immunity appeared after 3 weeks. Delayed hypersensitivity and antibody were already present on the 5th day of infection. Immunity to equine rhinopneumonitis virus infection could be transferred by both cells and antiserum, but not by lysed cells. Two types of immunity have been shown to be mediated by cells: anti-virus immunity which clears infection, and anti-protozoan immunity of the premunition type, sensitive to hypercorticism.