Details for: CL0000624

Cell ID: CL0000624

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

Description: A mature alpha-beta T cell that expresses an alpha-beta T cell receptor and the CD4 coreceptor.

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

Selected Context(s): Overall

Gene Significance Landscape

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Score:
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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 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 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 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 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:  CD4-positive, alpha-beta T cell (CL0000624)

 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 [CD4-positive, alpha-beta T cell](/details-cell/CL0000624) is a mature T lymphocyte central to the adaptive immune response, characterized by the expression of an alpha-beta T cell receptor (TCR) and the CD4 coreceptor. Gene significance analysis in the **Overall** context reveals that beyond its canonical immune role, this cell type is defined by an exceptionally high and specific expression (`csi_z`) of genes involved in protein synthesis and mitochondrial energy production. This suggests that [CD4-positive, alpha-beta T cells](/details-cell/CL0000624) are maintained in a state of high metabolic and biosynthetic readiness, poised for rapid activation, proliferation, and effector function upon antigen encounter. The top marker, [TPT1](/details-gene/7178), a translationally controlled tumor protein, underscores the cell's tight regulation of protein production, a critical aspect of its dynamic function. ## Key Characteristics and Function The gene expression signature of the [CD4-positive, alpha-beta T cell](/details-cell/CL0000624) highlights several core functional axes. * **High Metabolic Activity and Energy Production:** A prominent feature is the significant expression of numerous genes related to mitochondrial respiration. Genes encoding components of the cytochrome c oxidase complex, such as [COX1](/details-gene/4512), [COX2](/details-gene/4513), and [COX7C](/details-gene/1350), as well as [CYTB](/details-gene/4519) and ATP synthase components like [ATP5F1E](/details-gene/514), show high specificity. This metabolic profile indicates a strong reliance on oxidative phosphorylation, likely to meet the high energy demands required for constant immune surveillance and the energetic cost of rapid clonal expansion following activation. * **Biosynthetic Preparedness:** The cell exhibits a distinct signature of high-level translational machinery. The most specific marker, [TPT1](/details-gene/7178), along with the poly(A) binding protein [PABPC1](/details-gene/26986) and elongation factors [EEF1B2](/details-gene/1933) and [EEF1D](/details-gene/1936), all achieve high `csi_z` scores. This suggests that the cell maintains a robust capacity for protein synthesis, enabling the swift production of cytokines and other effector molecules upon stimulation. * **Immune Signaling and Antigen Presentation:** The expression of key immune-related genes is a defining characteristic. The high significance of the Interleukin-7 receptor, [IL7R](/details-gene/3575), is consistent with its crucial role in T cell survival and homeostasis. Furthermore, a strong and specific signature for MHC Class I pathway components, including [B2M](/details-gene/567), [HLA A](/details-gene/3105), [HLA B](/details-gene/3106), [HLA C](/details-gene/3107), and [HLA E](/details-gene/3133), is notable. While these cells are known for recognizing antigens via MHC Class II on other cells, their own robust MHC Class I expression highlights their capacity to present endogenous antigens, making them potential targets for cytotoxic cells and contributing to immune regulation. * **Cell Lineage Identity:** The **Anti Markers** profile clearly delineates the cell's lineage. The profound lack of significance for multiple immunoglobulin variable chain genes, such as [IGLV1 47](/details-gene/28822), [IGLV3 19](/details-gene/28797), and [IGKV3 15](/details-gene/28913), definitively confirms its identity as a T lymphocyte and distinguishes it from antibody-producing B cells. ## Clinical Significance and Contextual Roles Given its central role in orchestrating immune responses, the gene signature of the [CD4-positive, alpha-beta T cell](/details-cell/CL0000624) has profound clinical implications. The high significance of [IL7R](/details-gene/3575) is directly relevant to primary immunodeficiencies. As demonstrated by Puel et al., mutations in this gene can cause T(-)B(+)NK(+) severe combined immunodeficiency (SCID), highlighting its indispensable role in human T cell development ([Link](https://doi.org/10.1038/3877)). The strong expression of MHC Class I genes ([HLA A](/details-gene/3105), [HLA B](/details-gene/3106), [HLA C](/details-gene/3107)) underscores the cell's involvement in a wide range of immune-mediated pathologies. Polymorphisms in these HLA loci are strongly associated with susceptibility to autoimmune diseases, outcomes of infectious diseases, and the success of organ transplantation. The ability of these cells to present antigens makes them potential targets in viral infections like HIV, which selectively infects CD4+ T cells. The pronounced metabolic signature, characterized by high expression of mitochondrial genes like [COX1](/details-gene/4512), suggests that the metabolic state of these cells is a critical determinant of their function. In cancer immunotherapy, the metabolic fitness of CD4+ T helper cells within the tumor microenvironment is crucial for sustaining an effective anti-tumor response. Targeting metabolic pathways could therefore represent a therapeutic strategy to enhance T cell function in oncology. Similarly, the high expression of ferritin genes ([FTL](/details-gene/2512), [FTH1](/details-gene/2495)) points to a key role for iron metabolism in supporting the cell's high energetic and proliferative demands, a process that can be dysregulated in disease. ## Potential Mechanisms and Research Directions 1. **Hypothesis: CD4+ T cells are maintained in a state of "metabolic pre-activation" that enables rapid effector function.** The unusually specific expression (`csi_z`) of a broad suite of genes related to mitochondrial respiration and protein synthesis suggests these cells are not quiescent but are "poised" for immediate response. This state of heightened metabolic and translational readiness may allow them to bypass significant preparatory phases required by other cell types upon activation, facilitating a faster and more robust immune response. * **Surprising Findings:** The most specific molecular markers for this canonical immune cell are not T-cell-specific signaling molecules but rather components of general cellular machinery, including [TPT1](/details-gene/7178) (translation) and [B2M](/details-gene/567) (MHC I presentation). This finding re-frames the core identity of a CD4+ T cell from one defined solely by its TCR to one defined by its preparedness for high-output activity. * **Testable Questions:** Does the basal rate of oxidative phosphorylation and protein synthesis in naive [CD4-positive, alpha-beta T cells](/details-cell/CL0000624) significantly exceed that of other resting lymphocytes, such as naive B cells? Furthermore, upon TCR stimulation, do these cells exhibit a shorter lag time to effector cytokine production compared to cells that do not share this "poised" transcriptomic signature? 2. **Hypothesis: The robust MHC Class I expression on CD4+ T cells serves as a critical negative feedback mechanism to regulate immune responses.** While known as "helpers," the prominent signature of MHC Class I antigen presentation machinery ([B2M](/details-gene/567), [HLA A](/details-gene/3105), [HLA B](/details-gene/3106)) suggests they are also key targets. This may allow for the selective elimination of activated or virally-infected CD4+ T cells by cytotoxic T lymphocytes ([CD8-positive, alpha-beta T cell](/details-cell/CL0000625)) or NK cells, thereby contracting the helper T cell pool and preventing excessive or prolonged inflammation. * **Surprising Findings:** For a cell defined by its role in recognizing MHC Class II on antigen-presenting cells, it is striking that its own MHC Class I machinery is one of its most defining transcriptional features. This emphasizes a potentially underappreciated role for CD4+ T cells as targets of cytotoxic surveillance, rather than just directors of it. * **Testable Questions:** Can peptide-pulsed, activated [CD4-positive, alpha-beta T cells](/details-cell/CL0000624) be efficiently lysed by autologous [CD8-positive, alpha-beta T cell](/details-cell/CL0000625)s in vitro? Does blocking MHC Class I on the surface of these CD4+ T cells protect them from such killing and lead to an augmented helper response in a co-culture system?