Figure 1

B cells upregulate collagen secretion by dermal fibroblasts. Collagen release by dermal fibroblasts was determined by the Sircol collagen dye-binding assay in 3-day culture supernatants of NHDF or SScHDF cultured alone (white bars), cocultured with B cells (black bars), with PBMC (light gray bars), or recombinant TGF-β1 (5 ng/ml, dark gray bars). Data are expressed as the median of duplicate samples from independent experiments with B cells or PBMCs isolated from controls, NHDF from three different healthy individuals, and SScHDF from six different patients with SSc ± interquartile range. NS, not significant; ***P < 0.001.