CD8B Gene - CD8 Subunit Beta
Key Component of the CD8 Co-Receptor in Cytotoxic T Cells
Gene Information Card
| Symbol | CD8B |
|---|---|
| Full Name | CD8 Subunit Beta |
| Gene Type | Protein coding |
| Chromosomal Location | 2p11.2 |
| NCBI Gene ID | 926 ncbi.nlm.nih.gov/gene/926 |
| Ensembl ID | ENSG00000172116 |
| UniProt ID | P10966 |
| OMIM ID | 186730 |
| HGNC ID | 1707 |
| Aliases | CD8B1, CD8B2, LYT3, Leu2, T8 |
Description
The CD8B gene encodes the beta chain of the CD8 cell surface glycoprotein, a co-receptor expressed primarily on cytotoxic T lymphocytes. CD8 binds to major histocompatibility complex (MHC) class I molecules, facilitating T cell receptor (TCR) signaling and antigen recognition. The CD8 beta chain forms a heterodimer with the CD8 alpha chain (CD8A), and its expression is critical for normal T cell development and immune response.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| CD8 deficiency, autosomal recessive | Loss-of-function mutations in CD8B impair CD8+ T cell development and function, leading to recurrent infections and immune dysregulation. | OMIM #608957; PMID: 11133787 |
| Autoimmune lymphoproliferative syndrome (ALPS) | Defective CD8B may contribute to impaired apoptosis of lymphocytes, though direct evidence is limited. | OMIM #601859; PMID: 14578976 |
| HIV/AIDS susceptibility | Reduced CD8+ T cell count due to CD8B variants may influence HIV disease progression. | PMID: 16891410 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Spleen | 12.5 | Medium |
| Lymph node | 15.2 | Medium |
| Thymus | 18.7 | High |
| Blood | 22.1 | High |
| Bone marrow | 8.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Jurkat (T cell leukemia) | 25.4 | High expression |
| Raji (B cell lymphoma) | 0.5 | No significant expression |
| HEK293 (embryonic kidney) | 0.2 | No significant expression |
| K562 (erythroleukemia) | 1.1 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon, likely loss of function |
| c.82C>T (p.Arg28*) | Nonsense | Rare | Premature stop, loss of function |
| c.197G>A (p.Gly66Asp) | Missense | Rare | Impaired CD8 dimerization |
| c.312_313del (p.Leu105fs) | Frameshift | Rare | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense, frameshift, and start-loss mutations in CD8B lead to absent or nonfunctional CD8 beta chain, resulting in CD8 deficiency.
Gain of Function (GOF)
No gain-of-function mutations have been reported for CD8B.
Dominant Negative (DN)
No dominant-negative mutations have been described for CD8B.
View complete mutation data：
Gene Ontology (GO)
| • antigen binding (GO:0003823) | • transmembrane signaling receptor activity (GO:0004888) |
| • cell surface receptor signaling pathway (GO:0007166) | • cell surface (GO:0009986) |
| • integral component of membrane (GO:0016021) | • alpha-beta T cell receptor complex (GO:0042105) |
Pathways
• T cell receptor signaling pathway (KEGG: hsa04660)
• PD-1 signaling (Reactome: R-HSA-389948)
• Costimulation by the CD28 family (Reactome: R-HSA-388841)
Protein Summary
The CD8 beta chain (UniProt P10966) is a 210-amino acid type I membrane protein with a single extracellular immunoglobulin-like domain, a transmembrane region, and a short cytoplasmic tail. It forms a disulfide-linked heterodimer with CD8 alpha chain (CD8A). The CD8 beta chain is essential for proper CD8 co-receptor expression on the cell surface and for efficient MHC class I-restricted antigen recognition by cytotoxic T cells. Post-translational modifications include N-glycosylation at Asn-58.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CD8B Knockout HEK293 Cell Line | EDJ-KQ4214 | Human | 926 | Details Get a Quote |
| CD8B2 Knockout HEK293 Cell Line | EDJ-KQ4217 | Human | 927 | Details Get a Quote |
| CD8B Knockout HeLa Cell Line | EDJ-KQ52821 | Human | 926 | Details Get a Quote |
| CD8B Knockout A-549 Cell Line | EDJ-KQ61292 | Human | 926 | Details Get a Quote |
| CD8B Knockout HCT 116 Cell Line | EDJ-KQ69787 | Human | 926 | Details Get a Quote |
