Engineered biomaterial immunological niches as a surrogate for diseased tissue in chronic progressive EAE

We use a subcutaneous biomaterial implant as a surrogate for sampling immune cells phenotypes in murine chronic EAE. These implants are microporous polycaprolactone scaffolds that form immunological niches that get vascularized and capture both innate and adaptive immune cells. These niches can be minimally invasively biopsied, allowing for multiple samples to be collected from the same mouse at various timepoints in disease: presymptomatic (Day 7) and early state disease (Day 9). This study investigates immune dynamics over time in subclinical and early stage chronic progressive EAE at a distal biomaterial-based immunological niche. Overall design: Following subcutaneous implant of PCL microporous scaffolds, C57/B6J mice were given an adoptive transfer (AT) of MOG-reactive cells to induce chronic EAE or OVA-reactive cells as a healthy control. Scaffolds were explanted 7 (pre-symptomatic) and 9 days (early-stage disease; symptomatic) after AT and analyzed using scRNAseq.