Immunochemi'cal Differences between Glucocorticoid Receptors from Corticoid-sensitive and -resistant Malignant Lymphocytes1

We have explored the possibility of using antibodies against purified rat liver glucocorticoid receptors to study the immunochemical properties of glucocorticoid receptors from murine and human malignant lymphocytes. For this purpose, purified immune ¡mmunoglobulin G was covalently linked to Sepharose CL-4B. We then examined the ability of the affinity gel to recognize cytosolic [3H]triamcinolone acetonide-receptor com plexes from the corticoid-sensitive (CS) and -resistant strains of mouse lymphoma P1 798, from CS lymphocytes of patients with chronic lymphatic leukemia, and from a CS clone of human leukemic lymphoblasts in tissue culture (CH6). Mouse thymus was used as a source of glucocorticoid receptor from normal CS lymphocytes. Whereas the ¡mmunoaffinity column retained 70 to 84% of the 58to 62-Â (Stokes radius) [3H]triamcinolone acetonide-receptor complexes characteristic of the CS mouse and human lymphocytes, it failed to recognize the 27to 28-À (Stokes radius) glucocorticoid receptor present in corticoid-resistant mouse lymphoma P1 798 cells. Therefore, under appropriate experimental conditions, it was possible to demonstrate cross-reactivity between the antiserum against rat liver glucocorticoid receptor and the 58to 62-Ä (Stokes radius) glucocorticoid receptor from species as diverse as mouse and humans.