Fig. 5

IVIG treatment induces myelin gene and protein expression. Differentiation competent Schwann cells respond to IVIG interaction by increasing their myelin gene (a–h) and protein expression (i–l). Two days after differentiation was initiated, 20mg/ml dialysed IVIG and control buffer (ctrl) were added to the culture medium. Treatment of differentiating (diff.) and non-differentiating (non-diff.) cells was pursued for 7 days, with one medium change at day 4. a–h Quantitative RT-PCR revealed significant upregulation of most myelin genes after 7 days stimulation with IVIG (gray bars) or control buffer (black bars). i–j Western blot analysis confirmed increased P0 (i, j) and MBP (k, l) protein expression after 7-day stimulation of differentiating and non-differentiating Schwann cells. i, k representative Western-blots, j, l corresponding Odyssey quantifications. Protein molecular weights are indicated in kDa (kilodalton). m–o Quantification of in vitro myelination revealed a significant increase of MBP positive internodes (red) after 7 days IVIG treatment (o); β-tubulin staining (β-tub) is visualized in green. m, n Representative photographs of myelinating neuron/glia cocultures treated with either control buffer (m) or IVIG (n). GAPDH was used as normalization control in all experiments. t test (ns, not significant, *p < 0.05, **p < 0.01, ***p < 0.001). Error bars represent SEM. Scale bar, 100 μm. n = 10 for a, n = 8 for b, n = 4 for c, n = 7 for d, e, n = 5 for f, h, n = 3 for g, n = 5 for i–j, k–l, n = 9 for m–o