Ly-1 (CD5), a membrane glycoprotein of mouse T lymphocytes and a subset of B cells, is a natural ligand of the B cell surface protein Lyb-2 (CD72).

• DOI: 10.4049/jimmunol.148.6.1630
• Publication Date: 2022-12-31T09:40:14Z
• Authors: W Luo; H Van de Velde; I von Hoegen; J R Parnes; K Thielemans
• Keywords: CD5; Cell surface receptor

CD5 is a 67-kDa glycoprotein expressed on the cell surface membrane of all T lymphocytes and small proportion B lymphocytes. The physiologic role this Ag still unknown. Structural functional studies suggest that it might act as receptor for positive signal. CD5-specific mAb augment CD3- or mitogen-induced proliferation, IL-2 secretion, IL-2R expression induce rise in intracellular [Ca2+]. In report, we describe purification mouse protein (mCD5) its use probe to search ligand CD5. We demonstrate mCD5 specifically interacts with differentiation CD72/Lyb-2. Three serologically defined allelic forms CD72/Lyb-2 can interact mCD5. further show human CD72/Lyb-2, similarly, These may have major implications mechanisms T-B communication.