Fig. 4
Aging increases the frequency of GM-CSF+ cells within CD4+ T lymphocytes infiltrating the spinal cord of AO rats immunized for EAE. (Panel a) Overlaid flow cytometry histograms show GM-CSF expression in CD4+ T cells isolated on the 16th d.p.i. using MACS (described in detail in the section Methods) from spinal cords of (left) young and (right) aged rats. In the overlaid flow cytometry histograms left histograms (thin grey line) represent nonspecific binding of secondary antibody. Flow cytometry dot plots show IFN-γ vs IL-17 staining of GM-CSF+ CD4+ T cells retrieved from spinal cords of (left) young and (right) aged rats on the 16th d.p.i. Numbers in the flow cytometry profiles represent the percentage of cells in the indicated region. (Panel b) Bar graphs indicate the fold change in expression of mRNAs for GM-CSF and IL-3 in freshly isolated (Fresh) and PMA- and ionomycin-stimulated (PMA + iono) mononuclear spinal cord cells from aged relative to young rats on the 16th d.p.i. as determined by RT-qPCR. (Panel c) Bar graphs indicate the fold change in expression of mRNAs for IL-1β and IL-23/p19 in spinal cord mononuclear cells and IL-7 in spinal cord tissue from aged relative to young rats on the 16th d.p.i. as determined by RT-qPCR. Data are normalized to β-actin (ACTB). All results are presented as means ± SEM (n = 9/group). The data, except for GM-CSF, are representative of one of two experiments with similar results. *p < 0.05; **p < 0.01; ***p < 0.001