Details for: CL0000625

Cell ID: CL0000625

Cell Name: CD8-positive, alpha-beta T cell

Description: A T cell expressing an alpha-beta T cell receptor and the CD8 coreceptor.

Synonyms: CD8-positive, alpha-beta T lymphocyte, CD8-positive, alpha-beta T-cell, CD8-positive, alpha-beta T-lymphocyte

Selected Context(s): Overall

Gene Significance Landscape

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Score:
Display
Genes

Contexts:

Cell Significance Index (CSI) is uniquely calculated to reveal cell-specific gene markers. More info here

Significant Genes List

Genes with the highest and lowest Percentile Rank Scores (PRS) for CD8-positive, alpha-beta T cell within the selected context(s).

Gene ID: A unique numerical identifier for this specific gene.
Symbol: Shortened abbreviation or name that represents this gene.
Ensembl Gene ID: A unique identifier assigned by Ensembl for genomic data mapping.
CSI Score: A combined effect size and statistical significance measure for CD8-positive, alpha-beta T cell. Higher scores indicate a stronger, more significant difference in expression.
(Previously described as "Fold Change", but now represents Cliff's Delta × –log10(p).)

Gene ID: A unique numerical identifier for this specific gene.
Symbol: Shortened abbreviation or name that represents this gene.
Ensembl Gene ID: A unique identifier assigned by Ensembl for genomic data mapping.
CSI Score: A combined effect size and statistical significance measure for CD8-positive, alpha-beta T cell. Higher scores indicate a stronger, more significant difference in expression.
Average CSI: csi sum / gene count
Cell network configuration

This network visualizes key genes for CD8-positive, alpha-beta T cell. It primarily includes:
1. Top genes highly significant for this cell (Num. Top Cell Genes - based on the 'Min. CSI' setting).
2. Any additional specific 'Context Genes' you add below.
The final network is a combined view. Choose an Interaction Source (pathways or protein interactions) and optionally compare CSI scores with a Baseline Cell Type.

Maximum number of selected genes.
Select a context for the baseline cell.
Select a context for the target cell.
Target Cell for CSI:  CD8-positive, alpha-beta T cell (CL0000625)

 Legend
Nodes (Genes):
 Query Gene
Node size also reflects Target Cell CSI magnitude.
Node Color (Target Cell CSI in specific network):
 Very High
 High
 Medium
 Low
 Very Low
 N/A or Not Sig.
Edges (Interactions):
 STRING (Protein-Protein)
 ONTOLOGY (Shared Pathway)
 Colors vary by pathway category; default arrow applies.

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## Summary The [CD8-positive, alpha-beta T cell](/details-cell/CL0000625) is a critical component of the adaptive immune system, defined by its expression of an alpha-beta T cell receptor (TCR) and the CD8 coreceptor. The gene significance profile for this cell type is dominated by components of the Major Histocompatibility Complex (MHC) Class I antigen presentation pathway. **Overall**, the high specificity scores (`csi_z`) for [B2M](/details-gene/567), [HLA A](/details-gene/3105), [HLA B](/details-gene/3106), and [HLA C](/details-gene/3107) underscore its primary role in recognizing and eliminating cells presenting foreign or aberrant peptides, a hallmark of cytotoxic T lymphocyte (CTL) function. This molecular signature positions the [CD8-positive, alpha-beta T cell](/details-cell/CL0000625) as a key effector in cell-mediated immunity against viral infections and tumors. ## Key Characteristics and Function The molecular identity of the [CD8-positive, alpha-beta T cell](/details-cell/CL0000625) is strongly defined by a coordinated set of genes essential for its immunological function, metabolism, and signaling capabilities. * **MHC Class I Antigen Presentation and Cytotoxicity:** The most prominent feature of this cell is the high significance of genes involved in antigen presentation and T-cell-mediated cytotoxicity. [B2M](/details-gene/567) (beta-2-microglobulin), the light chain of MHC class I molecules, exhibits the highest expression specificity (CSI (Z-SCORE): 48.54). It is complemented by the high significance of the classical MHC class I heavy chain genes, [HLA A](/details-gene/3105), [HLA B](/details-gene/3106), and [HLA C](/details-gene/3107). This suite of markers confirms the cell's central role in the recognition of peptide-MHC complexes, which is the initiating step for its cytotoxic effector functions. * **High Metabolic and Translational Activity:** The data suggest a state of high metabolic readiness. [TPT1](/details-gene/7178) (Translationally Controlled Tumor Protein), a gene involved in protein synthesis and cell growth, shows a remarkably high specificity score (CSI (Z-SCORE): 47.94), nearly on par with [B2M](/details-gene/567). This indicates that robust translational capacity is a defining and unique characteristic of this cell type, likely required for the rapid production of cytokines and cytotoxic molecules upon activation. Other significant markers like [SLC25A6](/details-gene/293) (an ADP/ATP translocator) and [EEF1G](/details-gene/1937) (a translation elongation factor) further support the notion of a highly active metabolic and protein synthesis machinery. * **Immune Signaling and Interaction:** The profile includes genes involved in lymphocyte signaling and communication. [PTPRCAP](/details-gene/5790), a protein that associates with the protein tyrosine phosphatase CD45, is a significant marker, suggesting its involvement in modulating TCR signaling thresholds. The presence of [TNFSF13B](/details-gene/10673) (also known as BAFF) is also noteworthy, as this cytokine is a key survival factor for B lymphocytes, suggesting that [CD8-positive, alpha-beta T cells](/details-cell/CL0000625) may participate in regulating humoral immunity ([Link](https://doi.org/10.1084/jem.189.11.1747)). * **Chemokine and Platelet-Associated Factors:** A surprising finding is the significance of genes typically associated with platelets and megakaryocytes, such as [PF4](/details-gene/5196) (Platelet Factor 4) and [PPBP](/details-gene/5473) (Pro-Platelet Basic Protein). Their presence as specific markers may indicate a less-characterized role for these T cells in modulating coagulation and inflammation at sites of tissue injury or infection, potentially linking cell-mediated immunity with hemostasis. ## Clinical Significance and Contextual Roles **Overall**, the gene profile of the [CD8-positive, alpha-beta T cell](/details-cell/CL0000625) highlights its central importance in immune surveillance and disease. The profound significance of the highly polymorphic [HLA A](/details-gene/3105), [HLA B](/details-gene/3106), and [HLA C](/details-gene/3107) genes underscores the cell's role in transplantation immunology, where mismatches can lead to graft rejection, and in autoimmunity, where self-peptides presented by these molecules can trigger self-reactive T-cell responses. The evolution of this polymorphism is thought to be driven by pressure to present a wide array of pathogen-derived peptides ([Link](https://doi.org/10.1002/j.1460-2075.1988.tb03131.x)). While most top markers are related to core immune functions, the identification of [CACNA1A](/details-gene/773) is intriguing. Mutations in this gene, which encodes a P/Q-type voltage-gated calcium channel subunit, are known to cause neurological disorders such as familial hemiplegic migraine and episodic ataxia type-2 ([Link](https://doi.org/10.1016/s0092-8674(00)81373-2)). Its status as a marker for [CD8-positive, alpha-beta T cells](/details-cell/CL0000625) is unexpected and could suggest a role for this specific calcium channel in T-cell function or a potential link between immune dysregulation and certain neurological conditions. Similarly, the transcription factor [PLAG1](/details-gene/5324), implicated in pleiomorphic adenomas through promoter swapping mechanisms ([Link](https://doi.org/10.1038/ng0297-170)), is identified as a marker, though with a lower significance score. This may suggest that pathways governing its expression could be relevant in both lymphocyte biology and tumorigenesis. ## Potential Mechanisms and Research Directions 1. **Hypothesis: [CD8-positive, alpha-beta T cells](/details-cell/CL0000625) actively participate in thrombo-inflammation through the localized release of platelet-associated chemokines.** * **Surprising Findings:** The identification of [PF4](/details-gene/5196) and [PPBP](/details-gene/5473), canonical platelet alpha-granule proteins, as specific markers for a lymphoid cell type is highly unusual. It challenges the conventional view of these chemokines as being exclusively derived from the megakaryocyte/platelet lineage. * **Testable Questions:** Can TCR stimulation of human [CD8-positive, alpha-beta T cells](/details-cell/CL0000625) in vitro induce the de novo synthesis and secretion of [PF4](/details-gene/5196) and [PPBP](/details-gene/5473)? If so, does co-culture with these activated T cells or their supernatants modulate platelet activation or endothelial cell permeability? 2. **Hypothesis: The P/Q-type voltage-gated calcium channel, encoded in part by [CACNA1A](/details-gene/773), is a non-canonical regulator of cytotoxic granule exocytosis in [CD8-positive, alpha-beta T cells](/details-cell/CL0000625).** * **Surprising Findings:** A gene primarily known for its role in presynaptic neurotransmitter release and its association with inherited neurological channelopathies ([Link](https://doi.org/10.1016/s0092-8674(00)81373-2)) presents as a specific marker for a key cytotoxic immune cell. This suggests a conserved mechanism of regulated exocytosis between neurons and lymphocytes that relies on this specific channel. * **Testable Questions:** Does selective pharmacological blockade of P/Q-type calcium channels inhibit the release of granzyme B and perforin from antigen-stimulated [CD8-positive, alpha-beta T cells](/details-cell/CL0000625)? Furthermore, do T cells from patients with [CACNA1A](/details-gene/773) mutations exhibit impaired cytotoxic function?