EXPRESSION OF ANTI-DNA IMMUNOGLOBULIN TRANSGENES IN NON-AUTOIMMUNE MICE

SELF-REACTIVE B cells can be regulated by either deletion or inactivation 1. These manifestations of self-tolerance have been dramatically shown in transgenic mice in which the number of self-reactive cells has been artificially expanded 2,3. We have now extended these models to ask if B-cell tolerance as described for non-disease-associated antigens also operates for the targets of autoimmunity. The target we have chosen is DNA. Anti-DNA antibodies are diagnostic of certain autoimmune syndromes in humans and are a characteristic of the murine model of systemic autoimmunity, the MRI/Ipr mouse4. Antibodies to both single-stranded and double-stranded DNA have been implicated in disease 5,6. By generating anti-DNA transgenic mice, we have addressed the question of whether DNA-specific B cells are regulated in normal (non-autoimmune) mice. We indeed found that most transgenic B cells bind DNA, yet we failed to detect secreted anti-DNA. We suggest that as a consequence of their self-reactivity these B cells are developmentally arrested.