A Study of Tumor Allograft Sensitized Lymph Nodes in Mice

Abstract

Abstract The immunoglobulin synthesis by immune lymph node cells, which in vivo have been shown to transfer adoptively accelerated tumor allograft rejection and enhancement, was studied by in vitro techniques. Autoradiographs of tissue culture supernatants showed that lymph node cells that were sensitized for 5 days and were capable of mediating rejection immunity were producing peak amounts of IgM and increased amounts of 7Sγ2, but there was no increase in 7Sγ1 immunoglobulin when compared to unsensitized nodes. The autoradiographs of lymph node cells sensitized for 14 days, which in vivo transferred enhancement activity, showed that these cells synthesized maximal amounts of 7Sγ2 and 7Sγ1 immunoglobulins, but decreased amounts of IgM when compared to 5-day immune cells. There were no consistent differences in the synthesis of IgA by normal or immune lymph node cells. Fluorescent antibody studies confirmed the results of the tissue culture experiments and extended these findings by localizing the site of immunoglobulin production within the node to the hilar and medullary cord areas. While antisera specific for all immunoglobulin classes stained the mature germinal centers of 14-day nodes, the quality of the staining reaction suggested entrapment of immunoglobulin in these cortical areas rather than active synthesis. Concomitant with the development of transferable biologic activities and immunoglobulin synthesis by the allograft sensitized lymph node cells was the appearance of many large, immature blastoid cells within the node. A correlation of immunoglobulin synthesis by immune lymph node cells in vitro with accelerated rejection immunity and enhancement activity mediated in vivo is presented.