Effect of Anti-Lymphocyte Serum on Mouse Lymphoid Tissues in Vivo and in Vitro

Abstract

Heterologous antilymphocyte serum (ALS) and antilymphocyte globulin (ALG) are potent immunosuppressive agents, particularly in cell-mediated immunity and primary immune responses [1-3]. Their mode of action has been disputed, however, as well as the morphological changes seen in lymphoid tissues following treatment. Lymphocyte destruction and/or functional inactivation through a “blindfolding” mechanism or a “sterile” activation have been alternatively suggested as some of the possible mechanisms of action [1, 4-6]. These immunosuppressive agents have also shown specific effects on lymphocytesin vitro — i.e., cytotoxicity, leukoagglutination, mitogenic and blastogenic activity [7-10] — which have been extensively investigated both to clarify the mode of action of antilymphocyte sera and to develop in vitro methods to estimate their immunosuppressive effect in vivo [11-13]. Following these lines of research we became interested in possible modifications of some functions of lymphoid cells in vitro after ALS treatment.