Bone marrow cells were isolated according to the procedure outlined in the Stem Cell Technologies Technical Manual version 3.1.1 (http://www.stemcell.com/) and as described in previous work [6 (link)]. Briefly, each mouse was euthanized and the femurs were sterilely harvested, then placed and held on ice in Hanks' Balanced Salt Solution (HBSS) from Lonza Walkersville, MD, and transported to the laboratory. Bone marrow cells were extracted from the femurs using a 25 gauge needle with a 1 cc syringe, filled with approximately 1 ml cold sterile medium which was used to flush through the femur several times to release cells into a cell culture dish containing RPMI medium supplemented with FBS. The cells solution was immediately transferred to a 15 ml culture tube and placed on ice until needed. Cells were washed by centrifugation at 4°C, 300 × g for 10 min and were resuspended in RPMI Medium for culturing. Cell recovery and viability was determined by manual counting or automated counting using the Nexcellom Cellometer 2000.