CD4⁺ T cells are required for the DC-to-OCL differentiation in oc/oc mice. (A) Flow cytometric analysis of the mesenteric lymph nodes and the spleen of control oc/oc mice and CD4-depleted and DC-injected oc/oc mice. (B) Representative radiography of the femur and tibia of control oc/oc mice and CD4-depleted and DC-injected oc/oc mice. (C) The expression of Rank-l and M-csf was analyzed by real-time RT-PCR in the bone marrow of normal mice, control oc/oc mice, and CD4-depleted and DC-injected oc/oc. The results are the mean plus or minus SD of 3 or 4 mice in each group. All results are representative of 2 independent experiments. (D) Real-time RT-PCR analysis of CD4⁺ T cells or stromal cells purified from the bone marrow of +/+ and oc/oc mice. The results are the mean plus or minus SD of 6 or 7 mice in each group.