Generation of Bone Marrow Chimera (BMC) Mice

Ahr^+/− and Ahr^−/− mice were 6 weeks of age on the day of irradiation and 8 weeks of age for the CS exposures. CD45.2 recipient mice were treated with 2.5 mL of enrofloxacin (Baytril) per 250 ml of drinking water. After 3 days, mice were irradiated using X-RAD smart irradiator (9 Gy, 225 kVp, 13 mA, 526 s, whole body). The mice were then left for 16 hours, at which time bone marrow from CD45.1 donor mice were collected, resuspend in PBS, filtered and counted. The concentration was adjusted to 20 × 10⁶ cells/mL in order to deliver 4 × 10⁶ cells in 200 μl of PBS/mouse intravenous to the irradiated mouse. Mice were kept on antibiotics for 2 weeks, after which, chimeric mice were exposed to air or CS for 3 days and BAL cells analyzed. To verify the level of chimerism, bone marrow cells were isolated from AhR-KO^AhR and the control AhR-KO^ko mice following the last CS exposure. Bone marrow cells were stained with antibodies against C45.1 and CD45.2 followed by analysis via flow cytometry.