Details for: CL0000896

Cell ID: CL0000896

Cell Name: activated CD4-positive, alpha-beta T cell

Description: A recently activated CD4-positive, alpha-beta T cell with the phenotype CD69-positive, CD62L-negative, CD127-negative, and CD25-positive.

Synonyms: activated CD4-positive, alpha-beta T lymphocyte, activated CD4-positive, alpha-beta T-cell, activated CD4-positive, alpha-beta T-lymphocyte

Selected Context(s): Overall

Gene Significance Landscape

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Genes

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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 activated CD4-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 activated CD4-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 activated CD4-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 activated CD4-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:  activated CD4-positive, alpha-beta T cell (CL0000896)

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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 [activated CD4-positive, alpha-beta T cell](/details-cell/CL0000896) is an immune cell characterized by recent antigen engagement, marked by the surface expression of CD69 and CD25 and the downregulation of CD62L and CD127. The provided gene significance data for the **Overall** context suggests that this activated state is defined by a profound metabolic and biosynthetic reprogramming. This is evidenced by the high expression specificity of genes central to cellular respiration, such as [B2M](/details-gene/567) and multiple subunits of the cytochrome c oxidase complex (e.g., [COX4I1](/details-gene/1327), [COX1](/details-gene/4512)), alongside a suite of genes essential for protein translation and RNA processing (e.g., [TPT1](/details-gene/7178), [PABPC1](/details-gene/26986)). This signature portrays a cell that is not merely proliferating but is a highly active metabolic and protein synthesis engine, poised to execute its effector functions. ## Key Characteristics and Function The gene expression profile of the [activated CD4-positive, alpha-beta T cell](/details-cell/CL0000896) points towards several core functional clusters that define its biological state. * **High Metabolic Activity:** A dominant feature is the significant specificity of multiple genes involved in oxidative phosphorylation. This includes several subunits of the cytochrome c oxidase complex, such as [COX4I1](/details-gene/1327), [COX1](/details-gene/4512), [COX2](/details-gene/4513), and [COX7C](/details-gene/1350), as well as components of ATP synthase like [ATP5F1E](/details-gene/514) and [ATP5MG](/details-gene/10632). This strong signature indicates a massive upregulation of the mitochondrial respiratory chain, which is necessary to meet the high energetic demands of clonal expansion, cytokine production, and other effector functions following activation. The high specificity of [FTL](/details-gene/2512), the ferritin light chain, may support this metabolic state by managing iron, a critical cofactor for respiratory chain enzymes. * **Intense Biosynthesis:** The cell appears to be a factory for protein production. Top markers include genes crucial for translation elongation ([EEF1B2](/details-gene/1933), [EEF1D](/details-gene/1936)), mRNA stability ([PABPC1](/details-gene/26986)), and mRNA splicing ([HNRNPA1](/details-gene/3178)). The high CSI for [TPT1](/details-gene/7178), a translationally controlled tumor protein, further supports the notion of a cell geared for rapid protein synthesis and growth. * **Regulated Proliferation and Differentiation:** While activation implies proliferation, the high specificity of [BTG1](/details-gene/694), a known anti-proliferative gene, is noteworthy ([Link](https://doi.org/10.1002/j.1460-2075.1992.tb05213.x)). This suggests that the proliferative burst is tightly controlled. [BTG1](/details-gene/694) may function as a transcriptional coregulator that fine-tunes the activation program, potentially pushing the cell towards a specific effector lineage or preventing excessive expansion and subsequent exhaustion. * **T-Cell Identity and Trafficking:** Core T-cell identity is confirmed by the significance of genes like [CD3G](/details-gene/917], a component of the T-cell receptor complex. The high specificity of [B2M](/details-gene/567) (beta-2-microglobulin), a component of MHC class I molecules, underscores the cell's intense engagement in cell-to-cell communication within the immune system. Furthermore, the chemokine receptor [CXCR4](/details-gene/7852) stands out as a key marker, suggesting a defined role in cell trafficking and homing to specific tissue microenvironments. ## Clinical Significance and Contextual Roles **Overall**, the gene signature of the activated CD4+ T cell provides insights into its roles in both physiological immune responses and pathology. The pronounced metabolic profile, heavily reliant on oxidative phosphorylation ([COX4I1](/details-gene/1327), [COX1](/details-gene/4512)), highlights a potential vulnerability. In autoimmune diseases or transplant rejection, targeting mitochondrial respiration could be a therapeutic strategy to dampen the activity of these effector cells. Conversely, in cancer immunotherapy, enhancing this metabolic program could boost the efficacy of anti-tumor T-cell responses. The high specificity of the chemokine receptor [CXCR4](/details-gene/7852) is clinically significant. [CXCR4](/details-gene/7852) is not only a key regulator of lymphocyte trafficking but also serves as a co-receptor for HIV entry and is implicated in the metastasis of cancer cells. The prominence of [CXCR4](/details-gene/7852) in this cell's signature suggests that modulating its signaling could be critical in managing viral infections and controlling immune cell infiltration into tumors. Additionally, several top markers are linked to cellular regulation and growth. [BTG1](/details-gene/694) is a member of an antiproliferative gene family and is involved in chromosomal translocations in some B-cell leukemias ([Link](https://doi.org/10.1002/j.1460-2075.1992.tb05213.x)). Its defining role in activated T-cells suggests it may be a key regulator of lymphocyte homeostasis, and its dysregulation could contribute to lymphoproliferative disorders. The translationally controlled protein [TPT1](/details-gene/7178) is often overexpressed in tumors, and its specificity here highlights the common pathways shared between rapid physiological proliferation and pathological growth. ## Potential Mechanisms and Research Directions 1. * **Hypothesis:** The concurrent high specificity of genes driving intense oxidative phosphorylation (e.g., [COX4I1](/details-gene/1327), [COX1](/details-gene/4512)) and the anti-proliferative transcriptional regulator [BTG1](/details-gene/694) indicates a critical cellular checkpoint. We hypothesize that [BTG1](/details-gene/694) functions to uncouple clonal expansion from effector function, acting as a brake on cell division to channel the cell's massive metabolic output towards sustained and efficient cytokine synthesis and other helper activities, thereby preventing premature exhaustion. * **Surprising Findings:** The identification of an *anti-proliferative* gene, [BTG1](/details-gene/694), as a top defining marker for a cell type classically associated with rapid proliferation is highly unexpected and suggests a more complex regulatory program than simple expansion. * **Testable Questions:** In primary human CD4+ T cells, does shRNA-mediated knockdown of [BTG1](/details-gene/694) prior to activation lead to a higher proliferation rate but a decrease in per-cell production of key effector cytokines like IFN-gamma or IL-2? 2. * **Hypothesis:** The distinct combination of a highly specific trafficking receptor, [CXCR4](/details-gene/7852), and a specialized metabolic profile skewed towards oxidative phosphorylation suggests that these activated T cells are specifically primed to home to and function within microenvironments with unique metabolic demands or constraints, such as inflamed tissues or lymph node follicles. We hypothesize that [CXCR4](/details-gene/7852) signaling not only directs migration but also reinforces the metabolic phenotype required for survival and function in the target tissue. * **Surprising Findings:** Rather than a general upregulation of all metabolic machinery, the data show remarkable specificity for individual components of the electron transport chain (e.g., [COX4I1](/details-gene/1327), [COX7C](/details-gene/1350)). This implies the assembly of a particular 'flavor' of mitochondria optimized for a specific bioenergetic state, rather than a generic increase in energy production. * **Testable Questions:** Does the *in vitro* stimulation of activated CD4+ T cells with the [CXCR4](/details-gene/7852) ligand, CXCL12, further enhance the expression of genes related to oxidative phosphorylation, and does inhibiting the electron transport chain preferentially impair the migration of these cells toward a CXCL12 gradient?