CD2 is a cell adhesion molecule
Cell adhesion molecule
Cell Adhesion Molecules are proteins located on the cell surface involved with the binding with other cells or with the extracellular matrix in the process called cell adhesion....

 found on the surface of T cell
T cell
T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells , by the presence of a T cell receptor on the cell surface. They are...

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.


It interacts with other adhesion molecules, such as lymphocyte function-associated antigen-3 (LFA-3/CD58
CD58, or lymphocyte function-associated antigen 3 , is a cell adhesion molecule expressed on Antigen Presenting Cells , particularly macrophages....

) in humans, or CD48
CD48 is a human protein encoded by the gene....

 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 or IHC refers to the process of detecting antigens in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and...

 to identify the presence of such cells in tissue sections. The great majority of T cell lymphoma
Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...

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


Due to its structural characteristics, CD2 is a member of the immunoglobulin superfamily
Immunoglobulin superfamily
The immunoglobulin superfamily is a large group 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 based on shared structural features with immunoglobulins ; they all possess a...

; it possesses two immunoglobulin-like domains in its extracellular
In cell biology, molecular biology and related fields, the word extracellular means "outside the cell". This space is usually taken to be outside the plasma membranes, and occupied by fluid...



CD2 has been shown to interact
Protein-protein interaction
Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...

 with CD2BP2
CD2 antigen cytoplasmic tail-binding protein 2 is a protein that in humans is encoded by the CD2BP2 gene.-Further reading:...

, Lck
Lck is a protein that is found inside specialized cells of the immune system called lymphocytes. Lck is a tyrosine kinase, which phosphorylates tyrosine residues of certain proteins involved in the intracellular signaling pathways of these lymphocytes...

 and PSTPIP1
Proline-serine-threonine phosphatase-interacting protein 1 is an enzyme that in humans is encoded by the PSTPIP1 gene.-Interactions:PSTPIP1 has been shown to interact with PTPN12, PTPN18, BZW1, Abl gene, Wiskott-Aldrich syndrome protein and CD2....


Further reading

External links

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