CD84

CD84 is a protein that in humans is encoded by the CD84 gene. It is a member of the SLAM family of immunomodulatory receptors, and plays a crucial role in immune response and immune system regulation.

Structure

The CD84 protein is a type I transmembrane protein with an extracellular region composed of two immunoglobulin domains. The intracellular region contains two immunoreceptor tyrosine-based switch motifs (ITSMs), which are essential for its signaling function.

Function

CD84 is expressed on various immune cells, including B cells, T cells, monocytes, macrophages, and platelets. It functions as a homophilic adhesion molecule, meaning it binds to other CD84 molecules on neighboring cells. This interaction is thought to facilitate cell-cell communication and modulate immune responses.

In B cells, CD84 is involved in the regulation of antibody production. It can enhance the production of IgG and IgA, but suppress the production of IgE. In T cells, CD84 can modulate the activation and proliferation of these cells.

Clinical significance

Alterations in the expression or function of CD84 have been associated with various diseases. For example, increased expression of CD84 has been observed in chronic lymphocytic leukemia (CLL) cells, and it has been suggested as a potential therapeutic target for this disease. In addition, CD84 has been implicated in autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus.

See also

• Cluster of differentiation
• Signaling lymphocytic activation molecule family