L-asparaginase induced immunosuppression: inhibition of bone marrow derived antibody precursor cells.

The cooperation between bone marrow and thymus cells in restoring the hemolytic antibody response to sheep erythrocytes in immunosuppressed recipients was markedly inhibited when donor mice were treated with L-asparaginase, a known inhibitor of lymphocyte function. The marrow cell population was shown to be a major target for the immunosuppressive activity of asparaginase, since thymus cells from enzyme-treated animals interacted with marrow cells from normal animals to generate immunocompetent cells.