Reduced level of CX3CR1 positive T-cells and monocytes in children with, newly diagnosed, Type 1 diabetes

Abstract

Abstract Background The chemokine CX3CL1 is associated with many autoimmune diseases. Type 1 diabetes (T1D) is an autoimmune disease characterized by an insufficient insulin production due to T-cells mediated destruction of pancreatic beta cells. CX3CL1/CX3CR1 plays an important role in recruitment and extravasation of T-cells and monocytes to the inflammatory site. Aim To investigate the role of CX3CL1 and its receptor CX3CR1 in children with T1D in acute phase (day 0), 10 days and 3 months after treatment compared to healthy subjects (HS). Methods Blood samples from children (range 2–18 years) with new onset type 1 diabetes (day 0 (n=14), day 10 (n=9) and 3 month (n=14)) and 24 age matched HS was collected. The concentrations of CX3CL1 in plasma (T1D day 0, day 10 and HS) was measured by ELISA. Receptor expression of CX3CR1 on monocytes and T-cells was analyzed by flow cytometry. Results The study showed significant higher concentrations of CX3CL1 in serum from T1D day 0 compared to HS (p<0.05) and T1D day 10 (p<0.01). No significant difference was observed between T1D at day 10 and HS. Furthermore, the level of CX3CR1 positive T-cells was significantly lower in T-cells from T1D day 0 compared to HS (p<0.003) and T1D 3 months (p<0.007). In addition, the amount CX3CR1 positive monocytes were significant lower in T1D day 0 compared to HS (p<0.003). Conclusion The low amount of CX3CR1 positive T-cells and monocytes in peripheral circulation in acute phase T1D, despite the high level of s-CX3CL1, indicate that the T-cells and monocytes might have transmigrated to the inflammatory site. This study indicates that CX3CL1/CX3CR1 axis could play a role in the pathogenesis of T1D.