Acid β-glucosidase insufficiency activates the C-X-C Motif Chemokine Ligand 9/CXCR3 axis leading to T cell mediated inflammation in Gaucher disease

Abstract

Abstract Gaucher disease (GD) is caused by GBA1 mutations that lead to decreased activity of lysosomal acid β-glucosidase and abnormal tissue accumulation of its substrate, glucosylceramide (GC). Monocyte lineage cells, e.g., macrophages (Mφs) and dendritic cells (DCs) are prominent disease effectors due to their massive accumulation of GC resulting in “Gaucher cells.” Interaction of Gaucher cells and T lymphocytes trigger massive secretion of IFNγ, TNFα, IL6, IL12p40, IL12p70, IL23, and IL17A/F, that leads to the tissue destruction in GD. The exact mechanisms that trigger excess tissue T cells recruitment in GD are still unclear. CXCR3+ T cells are enriched at inflammatory sites in patients with rheumatoid arthritis and multiple sclerosis. Using D409V/null (Gba19V/−) GD mouse model, this study uncovered the role of CXCR3 receptor and its C-X-C Motif Chemokine Ligand 9 (CXCL9) in induction of excess tissue recruitment of T cells in GD. Intracellular FACS staining of Mφs and DCs from Gba19V/− mice showed elevated amounts of CXCL9. CD4+ T and the CD8+ T cells purified from Gba19V/− mice showed increased amounts of CXCR3. Ex vivo and in vivo chemotaxis experiments, evaluated CXCL9’s recruitment of Gba19V/− T cells. Blockade of T-cell CXCL9 receptor using antibodies to CXCR3 caused marked reduction in their CXCL9-mediated chemotaxis in Gba19V/− mice. These data suggest that Gba1 defects and the resultant deficiency of acid β-glucosidase activate CXCL9-CXCR3 axis for enhanced tissue Tells recruitment of T cells in GD. Collectively, our results indicate a critical role for CXCR3 mediated T cell transmigration to sites of inflammation. Molecular targeting of CXCL9/CXCR3 axis may provide needed anti-inflammatory therapies in human patients with GD. Supported by Cincinnati Children’s Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA