Details for: CL0000771

Cell ID: CL0000771

Cell Name: eosinophil

Description: Eosinophils are also CD14-negative, CD32-positive, CD44-positive, CD48-positive, CD69-positive, CD192-negative, MBP1-positive, MBP2-positive, TLR2-negative, TLR4-negative, and lineage-negative (B220, CD2, CD14, CD19, CD56, CD71, CD117, CD123, CD235a (glycophorin A), and TER119). The cytokines IL-3, IL-5, and GM-CSF are involved in their development and differentiation. Usually considered CD16-negative, CD16 is observed on eosinophilic metamyelocyte.

Synonyms: eosinocyte, eosinophilic granulocyte, eosinophilic leucocyte, eosinophilic leukocyte, polymorphonuclear leucocyte, polymorphonuclear leukocyte

Selected Context(s): Overall

Gene Significance Landscape

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Score:
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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 eosinophil 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 eosinophil. 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 eosinophil. 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 eosinophil. 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:  eosinophil (CL0000771)

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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):
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 High
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 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 [eosinophil](/details-cell/CL0000771) is a terminally differentiated granulocyte, a type of white blood cell, critical for type 2 immune responses, particularly against helminth parasites and in the pathogenesis of allergic diseases. Based on gene significance analysis, the defining characteristic of this cell type, **Overall**, is not the expression of unique effector proteins but rather a highly specific and robust signature of genes involved in fundamental cellular processes. The top markers, identified by their exceptionally high expression specificity (csi_z), are dominated by genes controlling chromatin structure ([H2AZ1](/details-gene/3015), [H3-3B](/details-gene/3021)), RNA processing and translation ([NCL](/details-gene/4691), [PCBP2](/details-gene/5094)), and core metabolic pathways. This suggests that the [eosinophil](/details-cell/CL0000771) maintains a uniquely stable and active basal machinery, positioning it to rapidly execute its effector functions upon stimulation. ## Key Characteristics and Function Analysis of the top marker genes reveals several interconnected functional clusters that define the [eosinophil](/details-cell/CL0000771)'s cellular identity. * **Chromatin and Transcriptional Regulation:** A significant number of top markers are involved in maintaining chromatin structure and basal transcription. Genes such as [H2AZ1](/details-gene/3015) and [H3-3B](/details-gene/3021) are histone variants critical for nucleosome dynamics, and [HMGB1](/details-gene/3146) acts as a chromatin-binding protein. This suggests that the specific transcriptional landscape of eosinophils is defined by a distinct and stable chromatin architecture. * **RNA Processing and Protein Synthesis:** The most prominent functional group among the top markers consists of RNA-binding proteins essential for mRNA processing, stability, and translation. This includes nucleolin ([NCL](/details-gene/4691)), poly(rC)-binding protein 2 ([PCBP2](/details-gene/5094)), polyadenylate-binding protein 1 ([PABPC1](/details-gene/26986)), and several heterogeneous nuclear ribonucleoproteins ([HNRNPDL](/details-gene/9987), [HNRNPA2B1](/details-gene/3181), [HNRNPU](/details-gene/3192)). The high specificity of these genes indicates that post-transcriptional regulation is a central and defining feature of eosinophil biology, likely enabling the rapid translation of pre-existing mRNA transcripts into effector proteins upon activation. * **Metabolic Activity and Energy Production:** Eosinophils exhibit a strong signature of high metabolic activity. This is highlighted by the specific expression of ferritin heavy chain 1 ([FTH1](/details-gene/2495)), crucial for iron homeostasis, and multiple subunits of the mitochondrial cytochrome c oxidase complex ([COX4I1](/details-gene/1327), [COX5B](/details-gene/1329), [COX7C](/details-gene/1350)). This robust machinery for cellular respiration is consistent with the high energy demands of a motile, phagocytic cell that synthesizes and releases large quantities of cytotoxic proteins. * **Negative Markers of Lineage and State:** The list of anti-markers confirms the cell's identity as a terminally differentiated, non-proliferating cell. Genes associated with cell cycle progression, such as [CCNB2](/details-gene/9133), [TOP2A](/details-gene/7153), and [MKI67](/details-gene/4288), show very low significance. Furthermore, the low scores for certain myeloid signaling molecules like the chemokine [CXCL8](/details-gene/3576) and the C-type lectin [CLEC12A](/details-gene/160364) suggest that while eosinophils are granulocytes, their specific signaling and surface marker profile distinguishes them from other myeloid lineages like neutrophils and monocytes within the context of this dataset. ## Clinical Significance and Contextual Roles While this analysis is performed in an **Overall** context without a direct disease comparison, the key markers have significant clinical implications. Eosinophils are well-established mediators of allergic asthma, atopic dermatitis, and eosinophilic esophagitis. The identified genetic signature provides insight into their pathogenic potential. The highly active protein synthesis machinery, marked by genes like [NCL](/details-gene/4691) and [PABPC1](/details-gene/26986), is likely poised to rapidly produce and degranulate well-known eosinophil effector proteins (e.g., major basic protein, eosinophil cationic protein), which cause tissue damage in allergic inflammation. Moreover, [HMGB1](/details-gene/3146), a top marker, is not only a chromatin protein but also a potent damage-associated molecular pattern (DAMP) when released extracellularly, capable of amplifying inflammatory responses. The specific expression of [HMGB1](/details-gene/3146) in eosinophils suggests they may contribute to sterile inflammation by releasing this alarmin. Similarly, the high expression of ferritin ([FTH1](/details-gene/2495)) points to a role in managing iron, a critical process during infection and inflammation that can influence host-pathogen interactions and oxidative stress. The stable, robust expression of these core cellular components may render eosinophils resilient in inflamed tissue microenvironments, allowing them to persist and exert their functions over time. Understanding the regulation of this core machinery could offer new therapeutic avenues for controlling eosinophil-driven pathologies. ## Potential Mechanisms and Research Directions 1. **Hypothesis: The "Housekeeping" Signature Represents a State of Poised Activation.** The high specificity (`csi_z`) of fundamental genes involved in transcription, translation, and metabolism may not indicate simple overexpression, but rather a uniquely stable and optimized cellular infrastructure. This stable platform could keep the [eosinophil](/details-cell/CL0000771) in a terminally differentiated yet "poised" state, ready to rapidly translate effector protein mRNAs upon receiving a stimulus, such as IL-5 signaling. * **Surprising Findings:** It is highly unexpected that the most specific genetic markers for a specialized immune effector cell are not its unique cytotoxic proteins or surface receptors, but rather a suite of ubiquitously expressed housekeeping genes. This challenges the conventional approach of identifying cell types solely by their most unique gene products. * **Testable Questions:** Does single-cell ATAC-seq analysis reveal a uniquely open and stable chromatin state at the loci of these top housekeeping markers ([H2AZ1](/details-gene/3015), [NCL](/details-gene/4691)) in eosinophils compared to other granulocytes? 2. **Hypothesis: Eosinophil Effector Function is Primarily Controlled at the Post-Transcriptional Level.** The striking prominence of numerous RNA-binding proteins ([PCBP2](/details-gene/5094), [PABPC1](/details-gene/26986), [HNRNPA2B1](/details-gene/3181)) as highly specific markers suggests that a critical layer of regulation in eosinophils occurs after transcription. These cells may pre-emptively transcribe mRNAs for key effector proteins and store them in a translationally repressed state. The specific cohort of RNA-binding proteins would then act as a molecular switchboard, releasing specific mRNAs for rapid translation in response to different activating signals. * **Surprising Findings:** The data implies that the identity and function of an [eosinophil](/details-cell/CL0000771) may be defined more by *how* it regulates its proteins (via RNA control) than *which* proteins it can make. This shifts the focus from the transcriptional to the post-transcriptional landscape. * **Testable Questions:** Can RIP-Seq (RNA immunoprecipitation sequencing) for top RNA-binding proteins like [PCBP2](/details-gene/5094) in resting versus activated human eosinophils identify a set of bound mRNA targets, and do these targets include key granule proteins and cytokines known to be released upon activation?