Evidence for Cell-Mediated Immunity and Specific Suppressor T Lymphocyte Dysfunction in Graves’ Disease and Diabetes Mellitus*

Migration inhibition of purified peripheral T lymphocytes in response to pancreatic islet cell antigen or thyroid antigen was used to study cell-mediated immune mechanisms in patients with diabetes mellitus (IDDM) and Graves' disease (GD). In response to islet cell antigen, T lymphocytes of subjects with IDDM for less than 3 yr exhibited migration inhibition, whereas those of normal subjects, noninsulin dependent diabetics, and subjects with IDDM for longer than 3 yr did not. Admixture of T lymphocytes from normal subjects with T lymphocytes from patients with IDDM for less than 3 yr substantially ameliorated the migration inhibition of the IDDM subjects to islet cell antigen. Migration of T lymphocytes from GD subjects was markedly inhibited by thyroid antigen and marginally inhibited by islet cell antigen. Admixture of GD T lymphocytes significantly ameliorated the migration inhibition of IDDM T lymphocytes to islet cell antigen, despite sensitization to thyroid antigen of the GD T lymphocytes. We conclude: 1) sensitization to islet cell antigen in IDDM of recent onset is confirmed; 2) the ability of normal and GD T lymphocytes to ameliorate the migration inhibition of IDDM T lymphocytes strongly suggests correction of deficient suppressor T lymphocyte function; 3) the ability of GD T lymphocytes to ameliorate migration inhibition of IDDM T lymphocytes to islet cell antigen is evidence for an antigen-specific rather than a generalized suppressor T lymphocyte defect in GD; and 4) similarly, the normalization of migration index of GD T lymphocytes in response to thyroid antigen by those IDDM T lymphocytes not sensitized to thyroid antigen is again evidence for an antigen-specific and not a generalized suppressor T lymphocyte defect in IDDM.