|
CD5 molecule
|
|
| Identifiers | |
| Symbol | CD5 |
| Alt. Symbols | LEU1 |
| Entrez | 921 |
| HUGO | 1685 |
| OMIM | 153340 |
| RefSeq | NM_014207 |
| UniProt | P06127 |
| Other data | |
| Locus | Chr. 11 q13 |
CD5 is a cluster of differentiation found on a subset of IgM secreting B cells called B-1 cells, and also on T cells. B1 B cells have limited diversity of their B Cell Receptor (BCR) due to their lack of the enzyme terminal deoxynucleotidyl transferase (TdT) and are potentially self-reactive. CD5 serves to mitigate activating signals from the BCR so that the B1 cells can only be activated by a very strong stimuli (such as bacterial proteins) and not by normal tissue proteins. CD5 was used as a T cell marker until mABs against CD3 were developed. In humans, the gene is located on the q arm of chromosome 11[1]. CD72 serves as a ligand. T cells express higher levels of CD5 than B cells. CD5 is up-regulated on T cells upon strong activation. In the thymus, there is a correlation with CD5 expression and strength of the interaction of the T cell towards self-peptides.
