Single cell level characterization of immune cells in 10-week-old C57BL/6 knee joints and femur bone marrow

Post-traumatic Osteoarthritis (PTOA) occurs in about half of individuals who sustained articular injuries including tibial plateau fracture, meniscus tear, or an anterior cruciate ligament (ACL) rupture. We utilize a noninvasive tibial compression injury (TCI) model that can closely replicate the anterior cruciate ligament rupture in patients, which reliably initiates PTOA development. In other studies we utilize single-cell RNA sequencing to temporally explore differences in immune cell infiltration following injury. Although extreme care is taken during immune cell isolation to prevent contamination from bone marrow, we also wanted to rule out the possibility of contamination from bone marrow immune cells in our knee joint samples. Therefore, we proceeded to compare the neutrophil populations from uninjured joint (joint) to bone marrow (marrow) to identify the similarities and differences between these populations. Right knee joints and bone marrow obtianed from Femur/Tibial bones of 10-week-old C57BL/6 mice were collected and immune (Cd45+) cells were analyzed using scRNA-seq.