Joseph R. and Lynn C. Reynolds Professor Johns Hopkins University, United States
Lyme disease is the most widespread tick-borne disease in North America and is caused by the bacteria Borrelia burgdorferi (Bb). Roughly 10–15% of infections result in Bb dissemination to the brain which causes neuroborreliosis, a disease with symptoms including headaches, facial palsy, and long-term cognitive impairment. Though there are many in vivo and in vitro studies of Bb dissemination, they largely focus on assessing Bb transmigration at key time points rather than the actual process of extravasation, which is an inherently complex and dynamic interaction. Here, we use a 3D tissue-engineered microvessel model and perfuse fluorescently labeled Bb to model dissemination in generic (induced Endothelial Cell, iEC) and brain specific (induced Brain Microvascular Endothelial Cell, iBMEC) microvessels. Using high resolution confocal microscopy, we acquire time-lapses in real-time to record Bb-microvessel interactions. With this model, we find that Bb readily interact with iEC microvessels, but infrequently adhere and extravasate from iBMEC microvessels. Inflammation increases the interaction frequency in iECs, but not in iBMECs. Furthermore, three hours of Bb perfusion is not sufficient for significant endothelial activation, though it disrupts iEC barrier function. These findings provide a further understanding of the dynamics and mechanics of Bb adhesion and extravasation during dissemination.
