Reactivation in Vitro of Immunocompetence in Irradiated Mouse Spleen

Abstract

The restoration of immunological competence to irradiated adult mouse spleen was studied using an in vitro assay system. Competence of the spleen to evoke a graft versus host reaction in vitro was lost upon sublethal irradiation (550 R). Regeneration of immune competence occurred when such spleens were grown for 2–3 days in the presence of thymus tissue, but not when grown in the presence of a variety of other tissues. This thymic activity was demonstrated to occur across an intervening Millipore filter barrier. When lethal doses of irradiation were used, reactivation of immune competence did not occur unless both thymus and bone marrow were present. In this experimental situation the bone marrow appeared to supply the immunocompetent cells.

Role of the Thymus in the Development of Immunocompetence of Embryonic Liver Cells in Vitro

“…The assay for assessment of a gvh reaction was performed as described previously (3,4). Paired explants of neonatal F1-hybrid spleen fragments were placed in a double filter well assembly; appropriate test cells were then added.…”

Maturation of Hemolysin-Producing Cell Clones

“…Could it not be possible that the interaction between the marrow cell and thymus cell occurs at the level of the differentiation of the PPFC? For example the thymus cells may induce the differentiation of bone marrow stem cells into specific immunocompetent cells (22,26,27). This induction may or may not require the presence of antigen.…”

“…There is no question but that cell-cell interactions play a role in in vivo (16)(17)(18) and in vitro (5,8,15,(19)(20)(21)(22) antibody-producing systems. At least a two cell interaction is required in the transfer system first described by Claman et al (16).…”

The Enhancing Effect of Bone Marrow Cells on the Primary Immune Response of the Isolated Perfused Spleen

“…Globerson and Auerbach (1) reported that both thymus and bone marrow ceils were necessary to restore the ability of spleen fragments from lethally irradiated mice to initiate a graftvs.-host reaction in vitro. Claman et al (2) presented evidence that a mixture of thymus and bone marrow cells produced far more hemolytic antibody-forming cells in irradiated recipients than either cell type alone.…”

“…I n initial experiments, however, the yield of antibody-forming cells from the isolated perfused spleen alone has been low. 1 The present studies were done to determine whether this response could be enhanced by addition of bone marrow or peripheral blood cells to this system and to assess the role of various cellular components in the immune response. It has been shown that addition of bone marrow or peripheral blood lymphocytes to the medium perfusing the isolated spleen increases the number of antibody-forming cells produced after primary antigenic stimulation in vitro.…”