Cd8 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
CD8 (Cluster of Differentiation 8) is a co-receptor expressed on cytotoxic T cells that recognizes antigens presented by MHC class I molecules.
| Property |
Value |
| Gene Symbol |
CD8A, CD8B |
| Protein Name |
Cluster of Differentiation 8 |
| UniProt ID |
P01732 (CD8A), P10966 (CD8B) |
| Molecular Weight |
~32 kDa (CD8A), ~28 kDa (CD8B) |
| Protein Family |
Ig superfamily |
| Expression |
Cytotoxic T cells, NK cells |
CD8 is a co-receptor that:
- Binds to MHC class I molecules
- Associates with T cell receptor
- Enhances cytotoxic T cell activation
- Required for thymocyte development
- CD8+ T cell infiltration in AD brain
- Clonal expansion observed
- May reflect chronic antigen exposure
- Potential immune dysfunction
- CD8+ T cells in PD substantia nigra
- Cytotoxic attack on neurons
- Autoimmune component
- T cell abnormalities
- Immune dysfunction
- Understanding adaptive immunity
- Immunomodulation strategies
- T cell-based therapies
The study of Cd8 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Gate D, et al. (2020). CD8+ T cells accumulate in aging brain. Nature. PMID:32214250
- Sulzer D, et al. (2017). T cells in Parkinson's disease. Nat Immunol. PMID:28114292
- Bjorkqvist M, et al. (2008). T cells in Huntington's disease. J Exp Med. PMID:18625745
- Van Elssen CH, et al. (2014). CD8+ T cell function. Nat Rev Immunol. PMID:24854588
- Farber DL, et al. (2014). Human memory T cells. Nat Rev Immunol. PMID:25131910
CD8+ T cells are found in:
- Peripheral blood circulation
- Secondary lymphoid organs
- CNS in neurodegenerative diseases
- Perivascular spaces in brain
- Increased CD8+ T cells in AD/PD brains
- Clonal expansion suggests antigen-driven
- Potential for immunomodulatory therapy
- T cell receptor sequencing studies
- Antigen identification
- Immunomodulatory therapeutic approaches
- Biomarker potential for progression
- CD8+/CD4+ ratio in CSF
- Clonal expansion assessment
- T-cell receptor sequencing
- Immunomodulation strategies
- IL-2 therapy considerations
- Antigen-specific T cell therapy
- Gate D, et al. (2020). "CD8+ T cells accumulate in aging brain". Nature. PMID:32214250
- Sulzer D, et al. (2017). "T cells in Parkinson's disease". Nat Immunol. PMID:28114292
- Bjorkqvist M, et al. (2008). "T cells in Huntington's disease". J Exp Med. PMID:18625745
- Lck kinase association
- ZAP-70 recruitment
- LAT scaffold protein
- SLP-76 downstream signaling
- Perforin delivery
- Granzyme release
- Target cell apoptosis
- Immune synapse formation
- CD28 engagement
- CTLA-4 inhibition
- 4-1BB costimulation
CD8 plays a critical role in T cell development in the thymus. During positive selection, CD8+ thymocytes that recognize self-MHC class I molecules receive survival signals through CD8 co-receptor engagement. The CD8 co-receptor enhances the affinity of the T cell receptor (TCR) for peptide-MHC complexes, enabling proper thymic selection and maturation of cytotoxic T lymphocytes (CTLs).
Once activated, CD8+ cytotoxic T cells become effector cells capable of:
- Recognizing and eliminating virus-infected cells
- Targeting cancer cells for destruction
- Maintaining immune surveillance
- Providing long-term immunological memory
Following primary infection or vaccination, a subset of CD8+ T cells differentiates into long-lived memory T cells. These memory cells persist in the body and can rapidly respond to re-infection with the same pathogen. Memory CD8+ T cells can be subdivided into:
- Central memory (TCM): Reside in secondary lymphoid organs
- Effector memory (TEM): Circulate in peripheral tissues
- Tissue-resident memory (TRM): Localized in non-lymphoid tissues
In Alzheimer's disease, CD8+ T cells show:
- Clonal expansion in the brain and cerebrospinal fluid
- Evidence of antigen-driven activation
- Potential role in autoimmune responses against neuronal antigens
- Association with disease progression
CD8+ T cells in Parkinson's disease:
- Infiltrate the substantia nigra
- May contribute to dopaminergic neuron loss
- Show evidence of molecular mimicry with neuronal proteins
- Interact with alpha-synuclein
- T cell dysregulation observed in ALS patients
- CD8+ T cells may influence motor neuron survival
- Altered cytokine profiles in ALS patients
- Flow cytometry for peripheral blood analysis
- Immunohistochemistry for brain tissue
- Single-cell RNA sequencing
- T cell receptor sequencing
CD8+ T cell signatures may serve as:
- Progression biomarkers
- Treatment response indicators
- Disease staging tools