CD2 (cluster of differentiation 2) is a

cell adhesion molecule Cell adhesion molecules (CAMs) are a subset of cell surface proteins that are involved in the binding of cells with other cells or with the extracellular matrix (ECM), in a process called cell adhesion. In essence, CAMs help cells stick to each ...

found on the surface of

T cell T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell ...

s and natural killer (NK) cells. It has also been called T-cell surface antigen T11/Leu-5, LFA-2, LFA-3 receptor, erythrocyte receptor and rosette receptor.

Function

It interacts with other adhesion molecules, such as lymphocyte function-associated antigen-3 (LFA-3/ CD58) in humans, or CD48 in rodents, which are expressed on the surfaces of other cells. In addition to its adhesive properties, CD2 also acts as a co-stimulatory molecule on T and NK cells.

Diagnostic relevance

CD2 is a specific marker for T cells and NK cells, and can therefore be used in

immunohistochemistry Immunohistochemistry is a form of immunostaining. It involves the process of selectively identifying antigens in cells and tissue, by exploiting the principle of Antibody, antibodies binding specifically to antigens in biological tissues. Alber ...

to identify the presence of such cells in tissue sections. The great majority of T cell

lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). The name typically refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlarged lymph node ...

s and

leukaemia Leukemia ( also spelled leukaemia; pronounced ) is a group of blood cancers that usually begin in the bone marrow and produce high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or '' ...

s also express CD2, making it possible to use the presence of the antigen to distinguish these conditions from B cell

neoplasm A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

Classification

Due to its structural characteristics, CD2 is a member of the

immunoglobulin superfamily The immunoglobulin superfamily (IgSF) is a large protein superfamily of cell surface and soluble proteins that are involved in the recognition, binding, or adhesion processes of cells. Molecules are categorized as members of this superfamily ...

; it possesses two immunoglobulin-like domains in its

extracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...

portion.

Interactions

CD2 has been shown to interact with CD2BP2, Lck and PSTPIP1.

References

External links