Modulates B-cell activation responses. Signaling could be triggered by the binding of a lectin-like ligand to the CD24 carbohydrates, and transduced by the release of second messengers derived from the GPI-anchor. Promotes AG-dependent proliferation of B-cells, and prevents their terminal differentiation into antibody-forming cells.
B-cells. Expressed in a number of B-cell lines including P32/SH and Namalwa. Expressed in erythroleukemia cell and small cell lung carcinoma cell lines. Also expressed on the surface of T-cells.
Involvement in disease
Genetic variations in CD24 are associated with susceptibility to multiple sclerosis (MS) [MIM:126200]. A multifactorial, inflammatory, demyelinating disease of the central nervous system. Sclerotic lesions are characterized by perivascular infiltration of monocytes and lymphocytes and appear as indurated areas in pathologic specimens (sclerosis in plaques). The pathological mechanism is regarded as an autoimmune attack of the myelin sheat, mediated by both cellular and humoral immunity. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia and bladder dysfunction. Genetic and environmental factors influence susceptibility to the disease. Note=Polymorphisms in CD24 may act as a genetic modifier for susceptibility and progression of MS in some populations, perhaps by affecting the efficiency of CD24 expression on the cell surface.