Bone marrow chimeras
Recipient mice were 2–3-month-old B6 mice (CD45.1). Mice were irradiated with 7 Gy X-ray and then immediately injected intravenously (i.v.) with 5 × 106 BM cells from WT or CCR2 KO (CD45.2) under aseptic condition. Cells from WT or CCR2 KO mice were mixed with that of CD45.1 mice at a 1:1 ratio. One week before the radiation and 2 weeks after the injection, mice were given water with antibiotics (gentamicin and erythromycin). Eight weeks after the transfer and the sacrifice of the mice, FCM was performed.