Figure 6

Neuroimmunomodulation following IVIg treatment. (A) Brain sections of 12-month-old female 3xTg-AD mice (3-month treatment with IVIg or ctrl) were stained and imaged with fluorescence. Iba1 (microglial cells, red), human APP/Aβ (6E10 antibody, green), DAPI (blue). Sections shown are from the subiculum of the hippocampal formation. Blue, DAPI. Scale bar = 35 μm. Right: graph of the area occupied by Iba1 staining in amyloid plaques (n = 4 per group). Student t-test. P = 0.94. (B) Multiplex ELISA was used to quantify the cytokine levels in the parietotemporal cortex of 12-month-old mice (3-month treatment). The values were normalized to IL-10 concentrations (n = 7 to 8 NonTg, n = 10 to 12 ctrl and n = 12 to 13 IVIg animals per group). Data were analyzed using a Kruskal–Wallis test followed by Dunn’s multiple comparison test. *P <0.05, **P <0.01, ***P <0.001 versus NonTg group; ^## P <0.01 versus 3xTg-AD control group. (C) Inflammation markers and (D) fractalkine pathway in the cortex of mice treated with IVIg. One-way ANOVA with Tukey’s multiple comparison test. *P <0.05 versus NonTg group; ^# P <0.05 versus 3xTg-AD control group. (C,D) Immunoblot analyses. Left panels: mice treated from 9 to 12 months (n = 8 NonTg, n = 12 ctrl and n = 13 IVIg animals per group). Right panels: mice treated from 13 to 16 months (n = 7 to 8 NonTg, n = 12 to 13 ctrl and n = 13 to 14 IVIg animals per group). 3xTg-AD, triple-transgenic mouse model of Alzheimer’s disease; APP, amyloid precursor protein; ctrl, control (vehicle); DAPI, 4′, 6-diamidino-2-phenylindole; ELISA, enzyme-linked immunosorbent assay; GFAP, glial fibrillary acidic protein; GM-CSF, granulocyte-macrophage colony-stimulating factor; Iba1, ionized calcium-binding adaptor molecule 1; IL, interleukin; IVIg, human intravenous immunoglobulin; MCP-1, monocyte chemoattractant protein-1; NF-κb, nuclear factor-kappa B; NonTg, non-transgenic.