The transcription factor RFX5 coordinates antigen-presenting function and resistance to nutrient stress in synovial macrophages. Nature metabolism Hu, Z., Zhao, T. V., Huang, T., Ohtsuki, S., Jin, K., Goronzy, I. N., Wu, B., Abdel, M. P., Bettencourt, J. W., Berry, G. J., Goronzy, J. J., Weyand, C. M. 2022


Tissue macrophages (M?) are essential effector cells in rheumatoid arthritis (RA), contributing to autoimmune tissue inflammation through diverse effector functions. Their arthritogenic potential depends on their proficiency to survive in the glucose-depleted environment of the inflamed joint. Here, we identify a mechanism that links metabolic adaptation to nutrient stress with the efficacy of tissue M? to activate adaptive immunity by presenting antigen to tissue-invading T cells. Specifically, M? populating the rheumatoid joint produce and respond to the small cytokine CCL18, which protects against cell death induced by glucose withdrawal. Mechanistically, CCL18 induces the transcription factor RFX5 that selectively upregulates glutamate dehydrogenase 1 (GLUD1), thus enabling glutamate utilization to support energy production. In parallel, RFX5 enhances surface expression of HLA-DR molecules, promoting M?-dependent expansion of antigen-specific T cells. These data place CCL18 at the top of a RFX5-GLUD1 survival pathway and couple adaptability to nutrient conditions in the tissue environment to antigen-presenting function in autoimmune tissue inflammation.

View details for DOI 10.1038/s42255-022-00585-x

View details for PubMedID 35739396