Details for: CL0000233

Cell ID: CL0000233

Cell Name: platelet

Description: Platelets are reportedly CCR1-positive, CCR2-negative, CCR3-positive, CCR4-positive, CCR5-negative, CCR6-negative, CCR7-negative, CCR8-negative, CCR9-negative, CCR10-negative, CD16-positive, CD23-positive, CD32-positive, CD40-positive, CD41-positive CD42-positive, CD61-positive, CD62P-positive, CD64-positive, CD89-positive, CD102-positive, CD147-positive (activated platelets), CD154-positive (activated platelets), CD162-positive, CD209, CD282-positive, CD284-positive, CD289-positive, CD181-negative, CD182-negative, CD183-negative, CD184-positive, CLEC2-positive, GPVI-positive, JAMC-positive, PAR1-positive, PAR2-negative, PAR3-positive, PAR4-positive, TSP1-positive, and TXA2R-positive. Platelets can reportedly produce CCL2, CCL3, CCL5, CCL7, CCL17, CD40L, CXCL1, CXCL4, CXCL4L1, CXCL5, CXCL7, CXCL8, CXCL12, EGF, factor V, factor VII, factor XI, factor XIII, bFGF, histamine, IGF-1, IL-1beta, PAI-1, PDGF, plasminogen, protein S, serotonin, TGF-beta, TFPI, VEGF, and vWF.

Synonyms: anucleate thrombocyte, blood platelet, enucleate thrombocyte

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 platelet 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 platelet. 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 platelet. 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 platelet. 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:  platelet (CL0000233)

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Nodes (Genes):
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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 [platelet](/details-cell/CL0000233), or thrombocyte, is an anucleate cell fragment derived from megakaryocytes, primarily known for its critical role in hemostasis and thrombosis. The gene significance profile from the **Overall** context confirms its identity through the absence of nuclear and core mitochondrial machinery. However, the data reveals a surprisingly specific and prominent immunomodulatory signature. The top marker, [B2M](/details-gene/567), a component of MHC class I molecules, alongside other immune-related genes such as [HLA E](/details-gene/3133), [CD3D](/details-gene/915), and [CCL5](/details-gene/6352), suggests that [platelets](/details-cell/CL0000233) function not only as mediators of coagulation but also as active participants in both innate and adaptive immunity. ## Key Characteristics and Function Analysis of the top marker genes in the **Overall** context reveals several functional clusters that define the [platelet](/details-cell/CL0000233) phenotype. * **Immune Signaling and Antigen Presentation:** The most striking characteristic is the high significance of genes associated with the immune system. [B2M](/details-gene/567) (Beta-2-microglobulin), the top marker by specificity (CSI: 33.36), is an essential subunit of MHC class I molecules, crucial for antigen presentation. This is complemented by [HLA E](/details-gene/3133), a non-classical MHC class I molecule involved in regulating NK and T cell responses. The profile unexpectedly includes genes typically associated with T-lymphocytes, such as [CD3D](/details-gene/915) and [CD8B](/details-gene/926). The presence of the chemokine [CCL5](/details-gene/6352) and the cytotoxic enzyme [GZMA](/details-gene/3001) further underscores a potent immunomodulatory capacity. Genes like [TREML1](/details-gene/340205), a receptor involved in amplifying platelet activation, and [KLRB1](/details-gene/111796), an NK cell lectin-like receptor, solidify the role of [platelets](/details-cell/CL0000233) as key players at the interface of coagulation and immunity. * **Cytoskeletal Dynamics and Contraction:** As expected for a cell that undergoes rapid and dramatic morphological changes upon activation, genes encoding cytoskeletal and motor proteins are highly significant. This includes myosin light chains like [MYL6](/details-gene/4637) and [MYL12A](/details-gene/10627), and the actin-depolymerizing factor [CFL1](/details-gene/1072). These proteins are essential for shape change, granule secretion, and clot retraction. * **Metabolism and Storage:** The high significance of ferritin light chain ([FTL](/details-gene/2512)) and heavy chain ([FTH1](/details-gene/2495)) indicates a role in iron sequestration and management. Additionally, genes involved in polyamine metabolism, [OAZ1](/details-gene/4946) and [SAT1](/details-gene/6303), are prominent, suggesting their importance in regulating cellular processes, likely inherited from their precursor megakaryocytes. * **Cellular Identity Defined by Absence:** The anti-marker profile strongly reinforces the anucleate nature of [platelets](/details-cell/CL0000233). Genes involved in core nuclear functions, particularly mRNA processing and splicing (e.g., [HNRNPC](/details-gene/3183), [DDX5](/details-gene/1655), [PNISR](/details-gene/25957)), are among the least significant. Furthermore, a large number of genes encoding components of the mitochondrial electron transport chain (e.g., [COX3](/details-gene/4514), [ND3](/details-gene/4537), [ATP6](/details-gene/4508), [CYTB](/details-gene/4519)) show strong negative significance. This does not imply an absence of mitochondria, which are present and active in [platelets](/details-cell/CL0000233), but suggests that their transcriptional signature is not a defining feature compared to metabolically active nucleated cells. ## Clinical Significance and Contextual Roles The gene signature of [platelets](/details-cell/CL0000233) highlights their deep involvement in "thromboinflammation," a process where coagulation and inflammation are pathologically linked. The specific expression of immune-modulating molecules provides a mechanistic basis for the observed role of [platelets](/details-cell/CL0000233) in a variety of diseases beyond simple thrombosis. The high significance of [CCL5](/details-gene/6352), a potent chemoattractant for monocytes and T-cells, indicates that activated [platelets](/details-cell/CL0000233) are key initiators of inflammatory cell recruitment to sites of vascular injury or infection. The expression of antigen-presenting machinery components like [B2M](/details-gene/567) and [HLA E](/details-gene/3133) suggests that [platelets](/details-cell/CL0000233) could directly modulate adaptive immune responses, a role of increasing interest in autoimmune diseases, viral infections (e.g., COVID-19), and cancer metastasis. The unexpected markers [GZMA](/details-gene/3001) and T-cell associated molecules ([CD3D](/details-gene/915), [CD8B](/details-gene/926)) further suggest that [platelets](/details-cell/CL0000233) may carry a cargo that allows them to interact with or even mimic lymphocytes, potentially influencing immune surveillance and response in circulation. ## Potential Mechanisms and Research Directions 1. **Hypothesis: [Platelets](/details-cell/CL0000233) function as circulating immune sentinels that can directly modulate T-cell responses.** The specific and high-ranking significance of genes like [B2M](/details-gene/567), [HLA E](/details-gene/3133), and even canonical T-cell molecules such as [CD3D](/details-gene/915) and [CD8B](/details-gene/926), suggests a previously underappreciated role for [platelets](/details-cell/CL0000233) in adaptive immunity. These anucleate fragments may acquire these protein complexes from their megakaryocyte precursors or through direct interaction with lymphocytes (trogocytosis), enabling them to present antigens or deliver co-stimulatory/co-inhibitory signals at sites of inflammation. * **Surprising Findings:** The presence of core components of the T-cell receptor complex ([CD3D](/details-gene/915)) and the [CD8-positive, alpha-beta T cell](/details-cell/CL0000625) co-receptor ([CD8B](/details-gene/926)) as highly specific markers for an anucleate cell type is exceptionally unusual and points towards a novel mechanism of immune interaction. * **Testable Questions:** Can flow cytometry and immunofluorescence confirm the surface presence of CD3 and CD8 proteins on circulating human [platelets](/details-cell/CL0000233)? Does co-incubation of activated [platelets](/details-cell/CL0000233) with T-cells result in the transfer of these molecules, and does this transfer alter T-cell activation thresholds? 2. **Hypothesis: Activated [platelets](/details-cell/CL0000233) contribute directly to cell-mediated cytotoxicity through the release of granzymes.** The identification of [GZMA](/details-gene/3001) (Granzyme A) as a significant marker challenges the conventional understanding of platelet alpha-granule content. This suggests that upon activation, [platelets](/details-cell/CL0000233) may release proteases typically associated with cytotoxic lymphocytes, thereby directly contributing to host defense against pathogens or transformed cells, or conversely, contributing to tissue damage in inflammatory conditions. * **Surprising Findings:** While [platelets](/details-cell/CL0000233) are known to release a vast array of bioactive molecules, the specific expression of a key cytotoxic enzyme like Granzyme A is not widely recognized and expands their potential effector functions. * **Testable Questions:** Using sensitive proteomic methods like mass spectrometry, can Granzyme A protein be quantified in the releasate from thrombin-activated [platelets](/details-cell/CL0000233)? Furthermore, does this platelet-derived releasate induce apoptosis in target cell lines, and is this effect abrogated by a specific Granzyme A inhibitor?