T-CELL SUPPRESSION OF IMMUNOGLOBULIN-SYNTHESIS IN ATAXIA TELANGIECTASIA - RESTRICTION OF SUPPRESSOR ACTIVITY TO B-CELLS FROM UNRELATED DONORS

Ataxia telangiectasia is a genetically transmitted disorder, characterized by progressive neurologic dysfunction, superficial telangiectasia and abnormalities of cellular and humoral immunity. A 13-yr-old female with this disorder, whose peripheral T cells were found deficient in their ability to collaborate with B cells from unrelated normal individuals, but not from each of her parents and her sisters upon coculturing in the presence of pokeweed mitogen (PWM), was studied. The patient''s T cells (Tp) suppressed the Ig production by PWM-stimulated peripheral blood lymphocytes (PBL) from allogeneic normal individuals but not from her parents. Irradiated T cells from this patient could collaborate to produce Ig with allogeneic B cells. HLA studies revealed that PWM-induced Ig production by PBL from the relatives was not suppressed by Tp irrespective of HLA phenotype of the donor. Evidently, the TP subpopulation has both a genetically unrestricted helper and a genetically restricted suppressor, a hitherto unreported phenomenon.