Fig. 1.

Ovariectomy increases IL-7 and IL-15 levels that are produced by bone marrow CD11c⁺ cells. (A) Increased IL-7 and IL-15 mRNA expression in OVX mice: BMCs from sham-operated and OVX mice were separated by magnetic beads into CD45-positive and CD45-negative populations using magnetic beads. RNA was isolated from each subset and expression of cytokines analyzed by qRT-PCR (SYBR green; ABI). The data is expressed as the fold difference between OVX and sham-surgery, after normalizing to GAPDH expression (data is from 5 mice/group with 3 technical replicates/mouse). (B) Identification of IL-7–expressing cells: BMCs from OVX or sham-operated from IL-7eCFP reporter mice were analyzed by flow cytometry. Although two cell populations were found to express CFP in the bone marrow, only the CD45+ CD11b + CD11c + population changed in ovariectomized mice. (C) IL-7–expressing cells co-express IL-15: expression of IL-15 was examined using Western blots in sorted BMC CD45 negative (lane 2), hematopoietic (CD45⁺), CD45⁺ CD11c⁺, CD45⁺CFP⁺, and CD45⁺CFP⁻ (lane 1) cells. Representative Western blot of four experiments. (D) OVX leads to increased IL-7⁺ IL-15⁺ and CD11c⁺ cells: increased CD11c⁺ cells are observed post-OVX (top left panel) in bone sections, as well as triple-positive CD11c⁺ IL-7⁺ and IL-15⁺ (bottom-left) cells, but not all CD11c⁺ cells express IL-7 and IL-15 concurrently as shown in representative photomicrographs (right panels; yellow arrows are DAPI, CD11c, and cytokine positive). BMC = bone marrow cell; CFP = cyan-fluorescent protein; OVX = ovariectomized.