Enhancing effect of bacterial endotoxins on bone marrow cells in the immune response to SRBC.

The synergistic involvement of bone marrow (B) cells and thymus (T) cells in the immune response to sheep erythrocytes (SRBC) has been well established. Injection of both cell types into irradiated mice challenged with SRBC results in far greater than additive numbers of antibody-producing cells (1–3). An interpretation of these findings is that following the interaction of the T cell, the B cell and antigen, the B cell proliferates and differentiates into the antibody-forming cell (4). When the antibody response is augmented by bacterial endotoxins, the number of antibody-forming cells in the spleen is increased (5, 6). Thus the enhanced antibody response could be a result of increased proliferation of T cells, B cells or both. Recipient BDF1 mice were irradiated by whole body exposure to 1000 R from a 60CO source. B cells from donor BDF1 mice were flushed from femurs and tibias by using Hank's balanced salt solution (BSS). T cells were teased in BSS.