APRIL and TALL-I and receptors BCMA and TACI: system for regulating humoral immunity.
Yu G,
Boone T,
Delaney J,
Hawkins N,
Kelley M,
Ramakrishnan M,
McCabe S,
Qiu WR,
Kornuc M,
Xia XZ,
Guo J,
Stolina M,
Boyle WJ,
Sarosi I,
Hsu H,
Senaldi G,
Theill LE.
Department of Inflammation, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320-1799, USA.
We report that the tumor neurosis factor homolog APRIL (a proliferation-inducing ligand) stimulates in vitro proliferation of primary B and T cells and increases spleen weight due to accumulation of B cells in vivo. APRIL functions via binding to BCMA (B cell maturation antigen) and TACI (transmembrane activator and CAML-interactor) and competes with TALL-I (also called BLyS or BAFF) for receptor binding. Soluble BCMA and TACI specifically prevent binding of APRIL and block APRIL-stimulated proliferation of primary B cells. BCMA-Fc also inhibits production of antibodies against keyhole limpet hemocyanin and Pneumovax in mice, indicating that APRIL and/or TALL-I signaling via BCMA and/or TACI are required for generation of humoral immunity. Thus, APRIL-TALL-I and BCMA-TACI form a two ligands-two receptors pathway involved in stimulation of B and T cell function.
PMID: 10973284 [PubMed - indexed for MEDLINE]