Figure 5.

Heteromer formation with signalling-incompetent TRAILR2 or Fas has a negative impact on CD40 signalling. (a) NF-κB luciferase assay in 293T cells transiently transfected with 0.5 ng of CD40, 1 ng of CD40L (left panel) or with 0.5 ng of TACI, 1 ng of BAFF (right panel) and increasing amounts of GPI-anchored CD40, TRAILR2, Fas or TACI. One out of three independent assays with similar results is shown. (b) Flow cytometry analysis of TRAILR2-GPI, CD40 full-length and TACI full-length surface expression. (c) Left: surface expression levels of CD40 full-length, CD40-GPI and CD40 full-length in the presence of TRAILR2, detected by staining with Flag-CD40L. Right, surface expression levels of CD40-GPI and TRAILR2-GPI, detected by staining with an anti-TRAILR3 mAb recognizing the GPI-proximal region of the fusion receptors. MFI, mean of fluorescence intensity. (d) NF-κB luciferase assay in 293T cells transiently transfected with 0.5 ng of CD40, 1 ng of CD40L and increasing amounts of GPI-anchored Fas, Fas-ΔCRD1, CD40 and TACI. One out of two independent assays with similar results is shown. (e) Flow cytometry analysis of Fas and Fas-ΔCRD1 surface expression