Tofacitinib, an oral janus kinase inhibitor, induces CD86<sup>- </sup>MHC II<sup>+ </sup>macrophages

Tofacitinib (TOF) is an oral janus kinase (JAK) inhibitor for the treatment of rheumatoid arthritis, and has similar efficacy compared to biologic disease-modifying antirheumatic drugs. By inhibiting JAKs, TOF may modulate leukocyte development and activation at inflammatory sites. Major histocompatibility complex class II (MHC II) and B7 (CD80/CD86) co-stimulatory molecules expressed on macrophages play a crucial role in T cell activation. Although macrophages are critically involved in the pathogenesis of rheumatoid arthritis, the influence of TOF on macrophage functions remains to be investigated. In this study, to clarify the effect of TOF on macrophage activation, we focus on the expression of MHC II and CD86.