A proliferation-inducing ligand

A proliferation-inducing ligand (APRIL), also known as TNFSF13, is a member of the tumor necrosis factor (TNF) superfamily. It is a protein that in humans is encoded by the TNFSF13 gene. APRIL plays a crucial role in the regulation of immune system and lymphoid tissue development.

Function

APRIL is a cytokine that belongs to the tumor necrosis factor family. It is involved in the stimulation of B cells proliferation and immunoglobulin production. The protein is primarily produced by macrophages and to a lesser extent by T cells. It is highly expressed in tumors of diverse origins and is implicated in the regulation of tumor cell growth.

Structure

APRIL is a type II transmembrane protein, which means it is anchored in the cell membrane with its N-terminus inside the cell and its C-terminus outside. The extracellular portion of APRIL can be cleaved off and secreted as a soluble molecule. The protein is composed of a TNF homology domain (THD) and a unique C-terminal extension.

Clinical significance

APRIL has been implicated in various diseases, including autoimmune diseases, cancer, and infectious diseases. In autoimmune diseases, APRIL is often overexpressed, leading to excessive B cell activation and autoantibody production. In cancer, APRIL can promote tumor growth and survival by stimulating cell proliferation and inhibiting apoptosis. In infectious diseases, APRIL can enhance the immune response to pathogens by promoting B cell activation and antibody production.

See also

• B cell activating factor
• Tumor necrosis factor superfamily