# Immunomodulation by allograft endothelial cells

## TL;DR

This review explores how endothelial cells in transplanted tissues influence immune responses and promote graft survival.

## Contribution

The paper introduces the novel concept that endothelial cell phenotypes drive immunoregulation in transplanted tissues.

## Key findings

- Endothelial cell phenotypes affect graft alloantigenicity and immunoregulation.
- Long-term graft survival depends on immune-endothelial interactions in the tissue microenvironment.
- Post-transplant immunoregulation may evolve based on graft-specific endothelial characteristics.

## Abstract

It is increasingly appreciated that the expression of immunoregulatory molecules within tumors have potential to shape a microenvironment that promotes local immunoevasion and immunoregulation. However, little is known about tissue-intrinsic immunomodulatory mechanisms following transplantation. We propose that differences in the phenotype of microvascular endothelial cells impact the alloantigenicity of the graft and its potential to promote immunoregulation following transplantation. We focus this review on the concept that graft-dependent immunoregulation may evolve post-transplantation, and that it is dependent on the phenotype of select subsets of intragraft endothelial cells. We also discuss evidence that long-term graft survival is critically dependent on adaptive interactions among immune cells and endothelial cells within the transplanted tissue microenvironment.