FIGURE 5.

Activity of BAFF-APRIL heteromers on BAFFR-, BCMA-, and TACI-specific reporter cell lines. Clones of Jurkat cells stably transduced with the chimeric receptors hBAFFR:Fas, hBCMA:Fas, or hTACI:Fas were exposed to titrated amounts of the indicated single-chain BAFF-APRIL heteromers which, upon binding, can activate the surrogate intracellular Fas apoptotic pathway that leads to cell death. A, effect of FLAG-tagged single-chain ligands cross-linked with a fixed amount of anti-FLAG antibody on the indicated reporter cell lines. B, same as A, but with Fc-tagged single-chain ligands in the absence of cross-linkers. C, same as A, but with untagged single-chain heteromers (and FLAG-BBB without anti-FLAG), all in the absence of cross-linker. Data shown in A–C are representative of at least two experiments with comparable results.