Induction of ILT expression on nonprofessional antigen presenting cells: Clinical applications

Achieving tolerance toward solid organ allografts remains challenging. Nonprofessional antigen-presenting cells, mainly endothelial cells, representing the first barrier between the donor organ and the recipient immune system represent a promising platform to induce tolerance towards allografts without compromising the recipient's immune system. Expression of ILT3 and ILT4, two members of the immunoglobulin-like transcript (ILT) family, has been demonstrated in endothelial cells in vitro and in vivo resulting in modulated endothelium-dependent T-cell activation. We here review mechanisms and effects of ILT3/ILT4 upregulation on endothelial cells and their potential significance in solid organ transplantation.