B-lymphocyte stimulator and A proliferation-inducing ligand (BLyS (BAFF) and APRIL)

BLyS (BAFF, TNFSF13B) and APRIL (TNFSF13) are closely related cytokines of the tumor necrosis factor ligand superfamily. Both are produced predominantly by myeloid-lineage cells, but also by B and T cells. BLyS and APRIL are critical for B cell maturation, survival, and differentiation, largely via binding to receptors BCMA, TACI, and (for BLyS only) BAFF-R. They exist as homotrimers, can form biologically active heterotrimers, and are involved in signaling pathways that promote B cell proliferation and inhibit apoptosis. Dysregulated BLyS/APRIL signaling is implicated in autoimmunity (notably SLE and RA) and B cell-related malignancies. Therapeutic antagonists—mainly monoclonal antibodies and fusion proteins—target these molecules to modulate immune response.

Other names

BAFFB-cell activating factorTumor necrosis factor ligand superfamily member 13B (TNFSF13B)TALL-1THANKzTNF4Tumor necrosis factor ligand superfamily member 13 (TNFSF13)CD256TALL-2TRDL-1

Neutralization (fusion proteins/antibodies block receptor-ligand interactions, inhibit downstream survival/proliferation of B cells) Receptor blockade (prevent binding of cytokines to BCMA, TACI, or BAFF-R)