ABSTRACT
Immunomodulatory action of nuclear proteins derived from spleen and brain of immunized rats was found in ConA-stimulated mouse spleen lymphocyte cultures. In vitro experiments on 32P- or Dig-labeled promoter-enhancer region (-548 bp) of the human interleukin-2 (IL-2) gene showed specific DNA-nuclear protein complex formation for spleen (6-14 kD) and brain (21 kD) proteins. The functional influence of these trans-factors on the IL-2 promoter region was studied in the model system of Jurkat cells with the firefly luciferase (Luc) reporter gene. The spleen and brain proteins were shown to influence the membrane surface properties of thymic and spleen cells as revealed in a two-phase aqueous system. We conclude that both spleen and brain from immunized rats contain certain protein trans-factors which can be active in T cells and display a common mode of regulatory action the level of IL-2 gene.
