Cells Involved in the Immune Response

Abstract

Bone marrow cells obtained from normal adult rabbits responded with blastogenesis and triated thymidine incorporation when incubated with various protein antigens in vitro. Cell suspensions from normal lymph node, spleen or thymus did not respond. However, cell suspensions from rabbits immunized to human serum albumin [HSA] displayed an opposite behavior in that the bone marrow cells did not respond to HSA while spleen and lymph node cell suspensions responded markedly. Thymus cells did not respond. The reactivity of bone marrow cells toward other antigens was not affected by the prior administration of HSA. The bone marrow supplies the immuno-competent cells to the lymphoid tissues following the administration of antigen; bone marrow cells, unlike lymph node, spleen and thymus cells, appear capable of initiating a primary immune response in vitro.