抄録
In order to induce suppressor cells antigen pulsed J774 or P388D1 cells were intravenously injected to BALB/c mice. J774 and P388D1 cells are macrophage like cell lines originated from BALB/c and DBA/2 mice, respectively. However, it is considered that neither cell has Ia antigen on its cell surface.
In preparing antigen pulsed cells they were incubated with antigen and Mitomycin C for a short period prior to the administration to BALB/c mice (first recipient mice). Various days after the injection of antigen pulsed cells spleen cells of the first recipient mice were transferred to the other BALB/c mice (second recipient mice) and they were immunized with the same antigen as pulsed on the cells, simultaneously. To test the suppressor cell function, IgE antibody levels of the second recipients were measured with PCA titers.
Antigen specific suppressor cells were induced by antigen pulsed J774 cells, but not by antigen pulsed P388D1 cells. The activity of these suppressor cells depended on the number of injected antigen pulsed J774 cells. However, the suppressor cells were also induced in spleen cells of the first recipient mice immunized with the same antigen as pulsed on P388D1 cells 10 days after the injection of these cells.
J774 cells irradiated with UV light before pulsing of antigen lost the activity inducing suppressor cells. Factors released from J774 cells had higher potential to induce cytotoxic T cell (CTL) than those released from P388D1 cells. Considering these results in my experiment and data of these papers two signals are necessary to induce suppressor cells. The first signal may be the stimulation of lymphocytes by the antigen itself pulsed to la- macrophages and the second may be the factors released from these macrophages.
