CD5 (protein)

From Wikipedia, the free encyclopedia
Jump to: navigation, search
CD5 molecule
Protein CD5 (PBB).jpg
PDB rendering based on 2ja4.
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols CD5 ; LEU1; T1
External IDs OMIM153340 MGI88340 HomoloGene7260 GeneCards: CD5 Gene
RNA expression pattern
PBB GE CD5 206485 at tn.png
More reference expression data
Orthologs
Species Human Mouse
Entrez 921 12507
Ensembl ENSG00000110448 ENSMUSG00000024669
UniProt P06127 P13379
RefSeq (mRNA) NM_014207 NM_007650
RefSeq (protein) NP_055022 NP_031676
Location (UCSC) Chr 11:
60.87 – 60.9 Mb
Chr 19:
10.72 – 10.74 Mb
PubMed search [1] [2]

CD5 is a cluster of differentiation found on a subset of IgM-secreting B cells called B-1 cells, and also on T cells.[1] B-1 cells have limited diversity of their B-cell receptor 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 B-1 cells can only be activated by very strong stimuli (such as bacterial proteins) and not by normal tissue proteins. CD5 was used as a T-cell marker until monoclonal antibodies against CD3 were developed.

In humans, the gene is located on the long arm of chromosome 11. There is no ligand confirmed, even if CD72, a C-type lectin, may be considered a probable ligand.

T cells express higher levels of CD5 than B cells. CD5 is upregulated 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.

Immunohistochemistry[edit]

CD5 is a good immunohistochemical marker for T-cells, although not as sensitive as CD3. About 76% of T-cell neoplasms are reported to express CD5, and it is also found in chronic lymphocytic leukemia, hairy cell leukemia, and mantle cell lymphoma cells. It is commonly lost in cutaneous T-cell lymphoma, and its absence can be used as an indicator of malignancy in this condition. The absence of CD5 in T cell acute lymphoblastic leukemia, while relatively rare, is associated with a poor prognosis.[2]

References[edit]

  1. ^ "Entrez Gene: CD5 CD5 molecule". 
  2. ^ Leong, Anthony S-Y; Cooper, Kumarason; Leong, F Joel W-M (2003). Manual of Diagnostic Cytology (2 ed.). Greenwich Medical Media, Ltd. pp. 67–68. ISBN 1-84110-100-1. 

Further reading[edit]

External links[edit]