[Nature of the target cells in bone marrow B-suppressor action studied on a simplified model of suppression activity registration].

The addition of bone marrow cells to spleen cells and lymph node cells stimulates by mitogents, but not to fibroblast-like cells, leads to a significant reduction of DNA synthesis in mixed cultures in vitro. The suppression effects appears only in two days and the suppressor cell activity is the stronger, the intensive is the target cell proliferation. It is shown that intact bone marrow cells can suppress the lipopolysaccharide-activated bone marrow cell proliferation in vitro. A conclusion may be draw that cells of the lymphoid system serve as target cells for the bone marrow suppressor cells, and the role of these lymphoid system cells is to control immunogenesis processes by suppressing the target cell proliferation activity in the bone marrow.