Adherence of PBMCs is greater in endothelial cells activated by high-responder coculture supernatants in contrast to those from low responders. (A) The micrograph panels created using phase contrast show the different levels of PBMC adherence associated with high- versus low-responder donor conditioned coculture medium. Many PBMCs have bound to the endothelial cells and are visible as small, bright, rounded refractile cells against the endothelial monolayer in the left panel compared with low-responder donor cocultures (center) and negative control (right). For image information, see Document S1 (available on the Blood website; see the Supplemental Materials link at the top of the online article. (B) PBMC adherence is higher for endothelial cells activated by high-responder coculture supernatants in contrast to those from low responders and resting AECs. For each sample, 3 microscope fields were counted for the number of bound PBMCs per field and are shown as the mean (± SD).