CD8 Gene

CD8 Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">CD8 Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>CD8A, CD8B</td>
</tr>
<tr>
<td class="label">Gene Name</td>
<td>CD8 Alpha Chain, CD8 Beta Chain</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>2p11.2 (CD8A), 2p11.2 (CD8B)</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>931 (CD8A), 915 (CD8B)</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P01732 (CD8A), P10966 (CD8B)</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Immunoglobulin superfamily</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~25-32 kDa (heterodimer)</td>
</tr>
<tr>
<td class="label">Domain</td>
<td>Function</td>
</tr>
<tr>
<td class="label">Ig-like V-type domain</td>
<td>MHC class I binding</td>
</tr>
<tr>
<td class="label">Hinge region</td>
<td>Flexibility for optimal interaction</td>
</tr>
<tr>
<td class="label">Transmembrane domain</td>
<td>Membrane anchoring</td>
</tr>
<tr>
<td class="label">Cytoplasmic tail</td>
<td>Lck kinase recruitment, signaling motifs</td>
</tr>
<tr>
<td class="label">Target</td>
<td>Approach</td>
</tr>
<tr>
<td class="label">CD8+ T cell depletion</td>
<td>Anti-CD8 antibodies</td>
</tr>
<tr>
<td class="label">TCR modulation</td>
<td>Peptide vaccines</td>
</tr>
<tr>
<td class="label">Cytokine bl

CD8 Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">CD8 Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>CD8A, CD8B</td>
</tr>
<tr>
<td class="label">Gene Name</td>
<td>CD8 Alpha Chain, CD8 Beta Chain</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>2p11.2 (CD8A), 2p11.2 (CD8B)</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>931 (CD8A), 915 (CD8B)</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P01732 (CD8A), P10966 (CD8B)</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Immunoglobulin superfamily</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~25-32 kDa (heterodimer)</td>
</tr>
<tr>
<td class="label">Domain</td>
<td>Function</td>
</tr>
<tr>
<td class="label">Ig-like V-type domain</td>
<td>MHC class I binding</td>
</tr>
<tr>
<td class="label">Hinge region</td>
<td>Flexibility for optimal interaction</td>
</tr>
<tr>
<td class="label">Transmembrane domain</td>
<td>Membrane anchoring</td>
</tr>
<tr>
<td class="label">Cytoplasmic tail</td>
<td>Lck kinase recruitment, signaling motifs</td>
</tr>
<tr>
<td class="label">Target</td>
<td>Approach</td>
</tr>
<tr>
<td class="label">CD8+ T cell depletion</td>
<td>Anti-CD8 antibodies</td>
</tr>
<tr>
<td class="label">TCR modulation</td>
<td>Peptide vaccines</td>
</tr>
<tr>
<td class="label">Cytokine blockade</td>
<td>Anti-IFN-γ, Anti-TNF-α</td>
</tr>
<tr>
<td class="label">Migration inhibition</td>
<td>CCR5 antagonists</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">ALZHEIMER</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">761 edges</a></td>
</tr>
</table>

Cd8 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Pathway Diagram

Overview

CD8 (Cluster of Differentiation 8) is a co-receptor expressed on the surface of cytotoxic T lymphocytes (CTLs) and some natural killer (NK) cells. While traditionally studied in the context of adaptive immunity, CD8+ T cells have emerged as important players in neuroinflammation and neurodegenerative diseases. This page covers the CD8 gene structure, protein function, and its role in [Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), and other neurodegenerative conditions. [@gate2020]

Gene Information

Gene Structure

The CD8 co-receptor is composed of two polypeptide chains:

CD8A (Alpha Chain)

• Encoded by gene on chromosome 2p11.2
• Contains a signal peptide, V-type immunoglobulin domain, hinge region, transmembrane domain, and cytoplasmic tail
• The cytoplasmic tail contains signaling motifs essential for T cell function

CD8B (Beta Chain)

• Co-expressed with CD8A in most cytotoxic T cells
• Forms disulfide-bonded heterodimer with CD8A
• Contributes to stability and signaling

Protein Structure and Function

CD8 functions as a co-receptor in T cell receptor (TCR) signaling:

• Release of cytotoxic granules (perforin, granzymes)
• Fas-FasL mediated [apoptosis](/entities/apoptosis)
• Cytokine secretion (IFN-γ, TNF-α)

Key Structural Features

Expression Pattern

Immune System

• Cytotoxic T lymphocytes (CTLs): Majority of CD8+ T cells
• Some NK cells: Subset expressing CD8
• Thymocytes: Intermediate stage (CD8+CD4-)

CNS Border Immune Cells

Recent studies have identified CD8+ T cells at the:

• Meninges: Meningeal CD8+ T cells in normal aging and disease
• Choroid plexus: Epithelial barrier with immune surveillance
• Perivascular spaces: CNS-penetrating lymphocytes

Role in Neurodegeneration

Alzheimer's Disease

CD8+ T cells contribute to AD pathogenesis through:

• Peripheral immunity: Altered CD8+ T cell counts in AD patients
• CNS infiltration: CD8+ T cells found in AD brain parenchyma
• Cytotoxic activity: Potential direct killing of [neurons](/entities/neurons)
• Cytokine production: Pro-inflammatory IFN-γ, TNF-α

• Elevated CD8+/CD4+ ratio in AD peripheral blood
• CD8+ T cell clonality in AD brain tissue
• Correlation between CD8+ T cell markers and disease progression

Parkinson's Disease

In Parkinson's disease:

• Peripheral dysfunction: Reduced CD8+ T cell counts in early PD
• [α-Synuclein](/proteins/alpha-synuclein) reactivity: CD8+ T cells respond to α-synuclein epitopes
• Dopaminergic neuron toxicity: Potential direct cytotoxicity
• Autoimmune components: Shared epitopes between neurons and pathogens

ALS (Amyotrophic Lateral Sclerosis)

• CD8+ T cell infiltration in spinal cord
• Cytotoxic killing of motor neurons (theoretical)
• Regulatory dysfunction in end-stage disease

Multiple Sclerosis

• CD8+ T cells as primary effector cells in demyelination
• Epitope spreading to neuronal antigens
• CD8+ T cell-mediated axonal injury

Therapeutic Implications

Immunomodulatory Approaches

Challenges

• Balancing immune surveillance with suppression
• CNS penetration of immunomodulatory drugs
• Patient heterogeneity in immune profiles

Biomarkers

• CD8+ T cell count: Peripheral blood marker
• CD8+/CD4+ ratio: Immunosenescence indicator
• Clonal TCR sequences: CNS-infiltrating T cell signatures
• Soluble CD8: CSF biomarker candidate

Animal Models

• CD8 knockout mice: Used to study CD8+ T cell function
• Humanized mice: CD8+ T cell reconstitution for translational studies
• α-Synuclein transgenic mice: CD8+ T cell response studies

Research Directions

• Single-cell sequencing of CNS-infiltrating CD8+ T cells
• TCR repertoire analysis in neurodegenerative diseases
• Development of CNS-targeted immunomodulatory therapies
• Understanding age-related changes in CD8+ T cell function

Background

The study of Cd8 Gene 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.

External Links

• [NCBI Gene: CD8A](https://www.ncbi.nlm.nih.gov/gene/931)
• [NCBI Gene: CD8B](https://www.ncbi.nlm.nih.gov/gene/915)
• [UniProt: CD8A](https://www.uniprot.org/uniprot/P01732)
• [UniProt: CD8B](https://www.uniprot.org/uniprot/P10966)
• [GeneCards: CD8A](https://www.genecards.org/cgi-bin/carddisp.pl?gene=CD8A)
• [ImmPort: CD8 Pathway](https://www.immport.org/shared/genelists)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving CD8 Gene discovered through SciDEX knowledge graph analysis: