Fig. 8

Glial cells promote survival and proliferation of CD19⁺ B cells. a IFN-γ treatment stimulates BAFF production by primary murine astrocytes. Astrocyte and microglial cell cultures were stimulated with MCMV or the indicated pro-inflammatory cytokine (i.e., TNF-α and IL-6, 20 ng/ml; IL-1β and IFN-γ, 10 ng/ml; IFN-α and IFN-β, 200 U/ml). BAFF levels in the culture supernatants were assessed at 48 h post-stimulation using ELISA. Pooled data (mean ± SEM) presented are derived from four independent experiments. b CD19⁺ B cells obtained from MCMV-primed β-actin-luciferase transgenic mice were cultured in the presence (closed circles) or absence (open circles) of primary murine astrocytes obtained from wild-type animals at a ratio of 10:1. Cultures were maintained for 0, 1, 4, and 7 days post-reconstitution, and B cell survival was assessed via luminescence. Data are presented as mean RLU (relative light units) ± SD from triplicate samples and are representative of two independent experiments. c Enhanced proliferation of B cells (CD19 gated) during co-culture with primary astrocytes was detected following staining with anti-Ki67-APC Abs and flow cytometry at 1 and 4 days post-reconstitution. Histograms shown are representative of two independent experiments