CX3CL1 and endothelial dysfunction: However, here we show that IL-15 that is elaborated by endothelium promotes further activation and recruitment of T cells, triggering the antigen-independent release of TNF, which then perpetuates subendothelial inflammation in a feed-forward manner to further promote endothelial dysfunction, CX3CL1 release, and more T cell infiltration (Fig 7).