B cells “transduced” with TAT-fusion proteins can induce tolerance and protect mice from diabetes and EAE

Antigen-immunoglobulin fusion protein expressing B cells have been shown as excellent tolerogenic antigen-presenting cells in multiple disease models. Using efficient protein transduction by fusion with a HIV TAT protein transduction domain, we herein tested the TAT-fusion protein transduced B cells for their effects in antigen-specific tolerance induction in two animal models, experimental autoimmune encephalomyelitis (EAE) and type 1 diabetes. We demonstrated that transfer of TAT-MOG35-55 (myelin oligodendrocyte glycoprotein)-Ig 'transduced B cells' 10 days after EAE induction significantly protected mice from disease. Similarly, the onset of disease was delayed when NOD mice received insulin specific TAT-B9-23-B cells. Surprisingly, no protection against EAE was observed in a prophylactic protocol when transduced B cells were given before disease induction. Moreover, TAT-ovalbumin transduced cells were tolerogenic in primed but not naïve mice. Our results suggest that TAT-fusion protein transduced B cells were tolerogenic in antigen primed recipients, a condition clinically relevant to autoimmune diseases.