Engagement of IL-1 receptor accessory protein (IL-1RAcP) with the monoclonal antibody AY19 provides co-activating signals and prolongs the CD2-induced proliferation of peripheral blood lymphocytes

► We report the functional characterization of a new anti-IL-1RAcP mAb, AY19. ► AY19 mAb allows the detection of IL-1RAcP on T, B and NK lymphocytes and on monocytes. ► IL-1RAcP engagement with AY19 mAb enhances the PMA-induced proliferation of PBMC. ► The CD2-mediated proliferation of PBMC is prolonged upon IL-1RAcP targeting with AY19. ► AY19 mAb allows the generation of co-activating signals in lymphocytes.