HIGHLY RESTRICTED HUMAN T-CELL REPERTOIRE IN PERIPHERAL-BLOOD AND TISSUE-INFILTRATING LYMPHOCYTES IN OMENNS-SYNDROME

Omenn's syndrome is an inherited human combined immunodeficiency condi tion characterized by the presence of a large population of activated and tissue-infiltrating T cells. Analysis of the TCRB repertoire revea led a highly restricted TCRBV usage in three patients. More strikingly , T cell clones from the three patients expressed TCRB chains with VDJ junction similarities, suggesting a common antigenic specificity. Ana lysis of the TCRA repertoire in one patient also revealed a restricted TCRAV usage. Finally, analysis of the TCRBV repertoire of tissue-infi ltrating T cells in one patient suggested nonrandom tissue migration, These results suggest that the oligoclonal expansion of T cells observ ed in Omenn's syndrome could be the consequence of autoimmune prolifer ation generated by a profound defect in lymphocyte development.