CD2 (cluster of differentiation 2) is a cell adhesion molecule found on the surface of T cells and natural killer (NK) cells. It has also been called T-cell surface antigen T11/Leu-5, LFA-2, [5] LFA-3 receptor, erythrocyte receptor and rosette receptor. [6]
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. [7]
In addition to its adhesive properties, CD2 also acts as a co-stimulatory molecule on T and NK cells. [8]
CD2 is a specific marker for T cells and NK cells, and can therefore be used in immunohistochemistry to identify the presence of such cells in tissue sections. The great majority of T cell lymphomas and leukaemias also express CD2, making it possible to use the presence of the antigen to distinguish these conditions from B cell neoplasms. [9]
Due to its structural characteristics, CD2 is a member of the immunoglobulin superfamily; it possesses two immunoglobulin-like domains in its extracellular portion. [8]
CD2 has been shown to interact with CD2BP2, [10] Lck [11] and PSTPIP1. [12]
HLA class II histocompatibility antigen, DR alpha chain is a protein that in humans is encoded by the HLA-DRA gene. HLA-DRA encodes the alpha subunit of HLA-DR. Unlike the alpha chains of other Human MHC class II molecules, the alpha subunit is practically invariable. However it can pair with, in any individual, the beta chain from 3 different DR beta loci, DRB1, and two of any DRB3, DRB4, or DRB5 alleles. Thus there is the potential that any given individual can form 4 different HLA-DR isoforms.
Integrin, alpha L , also known as ITGAL, is a protein that in humans is encoded by the ITGAL gene. CD11a functions in the immune system. It is involved in cellular adhesion and costimulatory signaling. It is the target of the drug efalizumab.
CD155, also known as the poliovirus receptor, is a protein that in humans is encoded by the PVR gene. It is a transmembrane protein that is involved in forming junctions between neighboring cells. It is also the molecule that poliovirus uses to enter cells. The gene is specific to the primates.
CD49d is an integrin alpha subunit. It makes up half of the α4β1 lymphocyte homing receptor.
Leukosialin also known as sialophorin or CD43 is a transmembrane cell surface protein that in humans is encoded by the SPN (sialophorin) gene.
Major histocompatibility complex, class II, DR beta 4, also known as HLA-DRB4, is a human gene.
HLA class II histocompatibility antigen, DRB5 beta chain is a protein that in humans is encoded by the HLA-DRB5 gene.
Major histocompatibility complex, class II, DQ alpha 1, also known as HLA-DQA1, is a human gene present on short arm of chromosome 6 (6p21.3) and also denotes the genetic locus which contains this gene. The protein encoded by this gene is one of two proteins that are required to form the DQ heterodimer, a cell surface receptor essential to the function of the immune system.
HLA class II histocompatibility antigen, DP(W2) beta chain is a protein that in humans is encoded by the HLA-DPB1 gene.
HLA class II histocompatibility antigen, DRB3-1 beta chain is a protein that in humans is encoded by the HLA-DRB3 gene.
CD48 antigen also known as B-lymphocyte activation marker (BLAST-1) or signaling lymphocytic activation molecule 2 (SLAMF2) is a protein that in humans is encoded by the CD48 gene.
This gene encodes a member of the G protein-coupled receptor kinase subfamily of the Ser/Thr protein kinase family, and is most highly similar to GRK4 and GRK5. The protein phosphorylates the activated forms of G protein-coupled receptors to regulate their signaling.
Tyrosine-protein kinase BLK, also known as B lymphocyte kinase, is a non-receptor tyrosine kinase that in humans is encoded by the BLK gene. It is of the Src family of tyrosine kinases.
HLA class II histocompatibility antigen, DQ(6) alpha chain is a protein that in humans is encoded by the HLA-DQA2 gene. Also known as HLA-DXA or DAAP-381D23.2, it is part of the human leucocyte antigen system.
Attractin is a protein that in humans is encoded by the ATRN gene.
CD2 antigen cytoplasmic tail-binding protein 2 is a protein that in humans is encoded by the CD2BP2 gene.
HLA class II histocompatibility antigen, DX beta chain is a protein that in humans is encoded by the HLA-DQB2 gene.
CD205 also called Lymphocyte antigen 75 is a protein that in humans is encoded by the LY75 gene.
CD8a, is a human gene.
T-cell surface glycoprotein CD3 delta chain is a protein that in humans is encoded by the CD3D gene.