Figure 7.
Proposed model of IS-mediated immune dysfunction provoking endothelial damage in ESRD patients. IS, a key uremic toxin which is dramatically accumulated in patients with chronic renal dysfunction, induces secretion of TNF-α by human monocytes through the aryl hydrocarbon receptor (AhR). Upon stimulation with TNF-α, human endothelial cells predominantly produce CX3CL1, a specific chemokine ligand of CX3CR1, which is highly expressed on CD4+CD28− T cells. ESRD patients have a markedly higher frequency of circulating cytolytic CD4+CD28− T cells, which are significantly expanded under chronic exposure to TNF-α. These CD4+CD28−CX3CR1+ T cells are preferentially recruited by CX3CL1 and induce apoptosis of human endothelial cells upon TCR activation.