The bidirectional crosstalk between B and T cells is crucial to for the evolution of pathogenic autoantibodies. Evidence suggests that IFN-γ and retinoic acid (RA) play a significant role as regulators of this interaction. A02 will investigate the molecular mechanisms of the interaction between B and T cells in the evolution of pathogenic autoantibodies using pemphigoid diseases as prototypical example. Herein, A02 will first focus on the role of IFN-γ and RA in this interaction. The final aim of A02 is to develop new strategies treating autoimmune diseases by targeting the evolution of pathogenic autoantibodies.