CRISPRa engineered Elite macrophages enable adoptive cell therapy for rheumatoid arthritis

Abstract

<p>Rheumatoid arthritis (RA) is a poly-articular systemic autoimmune disorder characterized by infiltration of immune cells, synovial hyperplasia and joint destruction. Macrophages (M��s) can polarize into either pro-inflammatory M1 or anti-inflammatory M2 phenotype in response to different environmental signals. In RA, M��s are prone to polarize into the M1 phenotype. Reprogramming M��s has shown promise in treating diseases, <i>e.g.</i>, the chimeric antigen receptor-M�� (CAR-M)-based adoptive immunotherapy. Interleukin-10 (IL-10) is one of the pivotal factors for M2 polarization. Clustered regularly interspaced short palindromic repeats-based transcriptional activation (CRISPRa) harnesses the native machinery in cells to enable a quick and efficient increase of endogenous gene expression. Here, we combined a CRISPRa system with adoptive cell therapy to construct engineered lastingly interleukin-ten (IL-10) expressed M��s (Elite M��s). The Elite M��s possessed powerful anti-inflammatory capability and represented a pre-activated state of M2 M��s <i>in vitro</i>. The Elite M��s were more susceptible to an M2 inducer while resistant to M1 inducers. The Elite M��s displayed enhanced chemotactic characteristics, leading to accumulated <i>in vivo</i> distribution at inflamed sites. Systemic administration of the Elite M��s relieved inflammation, synovial hyperplasia and joint destruction in mouse models of RA. The Elite M��s constructed by CRISPRa hold promise for addressing the current unmet medical need in RA.</p>