Augmented T cell function leading to host damage in autoimmunity is supported by metabolic dysregulation, making targeting immunometabolism an attractive therapeutic avenue. Canagliflozin, a type 2 diabetes drug, is a sodium glucose co-transporter 2 (SGLT2) inhibitor with known off-target effects on glutamate dehydrogenase and complex I. However, the effects of SGLT2 inhibitors on human T cell function have not been extensively explored. Here, we show that canagliflozin-treated T cells are compromised in their ability to activate, proliferate, and initiate effector functions. Canagliflozin inhibits T cell receptor signaling, impacting on ERK and mTORC1 activity, concomitantly associated with reduced c-Myc. Compromised c-Myc levels were encapsulated by a failure to engage translational machinery resulting in impaired metabolic protein and solute carrier production among others. Importantly, canagliflozin-treated T cells derived from patients with autoimmune disorders impaired their effector function. Taken together, our work highlights a potential therapeutic avenue for repurposing canagliflozin as an intervention for T cell-mediated autoimmunity.

Immune-mediated inflammatory diseases (IMIDs) are commonly associated with complex coexisting conditions, and cardiovascular comorbidities are a common cause of mortality in systemic inflammation. Experimental models of disease provide an opportunity to dissect inflammatory mechanisms that promote damage to vascular tissues affected by comorbidity. Here, we describe methods to recover the thoracic aorta from mice during experimental inflammatory arthritis and assess vascular constriction responses by isometric tension myography. To complement the assessment of functional changes in the vasculature during inflammatory arthritis, we also outline a method to characterize vascular inflammation by immunohistochemistry.

Abstract Background/Aims Interleukin-27 (IL-27) regulates adaptive immune responses and is critical for the timely resolution of inflammation to restore tissue homeostasis. Studies have highlighted roles for IL-27 in limiting immune cell effector function, stromal cell responses and erosive joint pathology in clinical rheumatoid arthritis and experimental models of the disease. In the murine antigen-induced arthritis (AIA) model, IL-27 receptor-deficient (Il27ra-/-) mice develop severe synovitis associated with increased infiltration of synovial CD4+ T cells, development of synovial ectopic lymphoid-like structures and exacerbated cartilage and bone erosion. Similarly, mice with collagen-induced arthritis (CIA) administered IL-27 show improved joint pathology and reduced serum IFN-γ and IL-17 levels. Identifying mechanisms by which IL-27 regulates arthritis progression is key to understanding its therapeutic potential. Using RNA-sequencing of synovial tissue and joint-infiltrating CD4+ T cells we reveal that IL-27 regulates the magnitude of synovitis and genes in CD4+ T cells central to neutrophil recruitment. Methods Antigen-induced arthritis (AIA) was established in Il27ra-/- and wild-type control mice. RNA-sequencing was performed on whole synovial tissue and joint-infiltrating CD4+ T cells during the peak of joint inflammation and during the resolution of synovitis. Differentially expressed genes were interrogated by molecular pathway analysis and gene set enrichment analysis. CD4+ T cell culture assays, qPCR and ELISA were used to test and validate genes under IL-27 regulation. Results RNA-sequencing of whole synovial tissue revealed that pathways relating to CD4+ T cell and Th17 biology were significantly overrepresented in Il27ra-/- mice with AIA, consistent with a pathogenic role for these cells in inflammatory arthritis. Genes associated with neutrophil effector function (e.g. Elane, Padi4, Prtn3) and recruitment (e.g. Cxcl1, Cxcr2) were also highly expressed in Il27ra-/- synovium and was reflected in the increased number of Ly6G+CD11b+ neutrophils recovered from the joints of Il27ra-/- mice. In contrast to the transcriptomic analysis of inflamed synovial tissue, surprisingly RNA-sequencing of joint-infiltrating CD4+ T cells revealed that the expression of signature Th17 genes (e.g. Il17a, Il17f, Rorc) was comparable between WT and Il27ra-/- T cells. This implies that IL-27 predominantly regulates the magnitude of the joint CD4+ T cell infiltrate more than the effector characteristics of the infiltrating T cells. Differential gene expression analysis revealed heightened Cxcl1 expression in both whole synovial tissue and joint-infiltrating CD4+ T cells recovered from Il27ra-/- mice with AIA. CD4+ T cell differentiation cultures confirmed upregulation of Cxcl1 following T cell receptor activation and under Th1 polarizing conditions. Here, IL-27 suppressed the expression of CXCL1 at the mRNA and protein level. Conclusion Together, our data reveals a role for IL-27 in limiting CXCL1 expression in activated and joint-infiltrating CD4+ T cells, highlighting a novel mechanism by which IL-27 may integrate innate and adaptive arms of the immune response to regulate arthritis progression. Disclosure I. Burridge: None. S. Eastham: None. D.G. Hill: None. R. Andrews: None. B. Szomolay: None. N. Williams: None. S.A. Jones: None. G.W. Jones: None.