APRIL

APRIL(CD256) is the acronym for "A proliferation inducing ligand" also known as "Tumor necrosis factor ligand superfamily member 13" or TNFSF13. APRIL is a ligand of the TNF family. The coding gene(TNFSF13 gene) is located on chromosome 17p13.1. In the "cluster of differentiation" terminology, APRIL is listed as CD256.

APRIL interacts with the receptors BCMA and TACI as well as with proteoglycans of the cell membrane (Treml et al. 2008). In vitro experiments suggest that this protein can induce apoptosis through its interaction with other TNF receptor family proteins. Alternative splicing results in several transcript variants.

APRIL and BAFF are produced in various hematopoietic and nonhematopoietic cell lines. In particular, myeloid cells produce large amounts of BAFF, and cell types that produce BAFF and APRIL include monocytes, macrophages, dendritic cells (DCs), neutrophils, mast cells, eosinophils, and astrocytes.

APRIL has also been detected in tumor tissues. It has also been shown that APRIL increases the number of B lymphocytes circulating in the periphery and has a suppressive effect on the T cell-triggered immune response (Castigli et al. 2004).

Diseases associated with TNFSF13 include brain glioblastoma multiforme and rheumatoid arthritis. Related signaling pathways include PEDF induced signaling and TRAF pathway. An important paralog of this gene is TNFSF12-TNFSF13.

1. Aggarwal BB (2003). Signalling pathways of the TNF superfamily: a double- edged sword. Nat Rev Immunol3: 745-756
2. Bannish G et al (2001) Ligand-dependent signaling functions for the B lymphocyte antigen receptor and their role in positive selection during B lymphopoiesis. J Exp Med 194:1583-1596.
3. Baert L et al (2018) The role of APRIL - A proliferation inducing ligand - In autoimmune diseases and expectations from its targeting. J Autoimmun 95:179-190
4. Castigli E et al (2004) Impaired IgA class switching in APRIL- deficient mice. Proc Natl Acad Sci USA 101: 3903-3908
5. Treml JF et al (2008) The BLyS Family: Toward a Molecular understanding of B Cell Homeostasis. Cell Biochem Biophys 53: 1-16.