Details for: CL0000875

Cell ID: CL0000875

Cell Name: non-classical monocyte

Description: Markers: CCR2-CX3CCR1+ (human, mouse, rat); human: CD16+, CCR5+, CD32/FcgRII-high, MHCII+, CD86+; mouse: CD62L-Ly6C-.

Synonyms: patrolling monocyte, resident monocyte

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 non-classical monocyte 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 non-classical monocyte. 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 non-classical monocyte. 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 non-classical monocyte. 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:  non-classical monocyte (CL0000875)

 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 [non-classical monocyte](/details-cell/CL0000875), also known as the patrolling or resident monocyte, is a distinct subset of myeloid cells characterized by its surveillance role within the vasculature. The gene significance profile from an **Overall** context strongly suggests this cell is defined by an exceptionally specialized and highly active metabolic state. The most specific gene markers are not traditional immune receptors, but rather components of iron homeostasis ([FTL](/details-gene/2512), [FTH1](/details-gene/2495)) and cellular metabolism ([OAZ1](/details-gene/4946)), indicating that its unique identity is deeply rooted in its capacity to manage iron and fuel its constant patrolling function. ## Key Characteristics and Function Analysis of top markers by expression specificity (`csi_z`) reveals several core functional clusters that define the [non-classical monocyte](/details-cell/CL0000875). * **Iron Homeostasis and Oxidative Stress Management:** The most defining characteristic of this cell type is the highly specific expression of the ferritin light and heavy chain genes, [FTL](/details-gene/2512) (CSI: 69.55) and [FTH1](/details-gene/2495) (CSI: 64.10). Ferritin is the primary intracellular iron storage protein, and its prominent expression suggests a crucial role in iron sequestration. This may serve to protect the local microenvironment, particularly vascular endothelium, from iron-induced oxidative damage. This function is consistent with a cell constantly patrolling the bloodstream. * **High-Energy Metabolism:** The cell exhibits a strong signature of high metabolic activity, underscored by the specific expression of numerous genes involved in mitochondrial oxidative phosphorylation. Key markers include multiple subunits of cytochrome c oxidase ([COX1](/details-gene/4512), [COX2](/details-gene/4513), [COX7C](/details-gene/1350), [COX4I1](/details-gene/1327)) and ATP synthase ([ATP5F1E](/details-gene/514), [ATP6V0C](/details-gene/527)). This powerful energetic machinery is likely essential to fuel the continuous motility and surveillance functions characteristic of patrolling monocytes. * **Polyamine Metabolism and Regulation:** Genes regulating polyamine metabolism, such as [OAZ1](/details-gene/4946) (ornithine decarboxylase antizyme 1) and [SAT1](/details-gene/6303) (spermidine/spermine N1-acetyltransferase 1), are among the top five most specific markers. Polyamines are critical for various cellular processes, and the specific expression of their regulators suggests a tightly controlled system governing the cell's activation state, differentiation, or lifespan. * **Immune Signaling and Antigen Presentation:** Consistent with its immune role, the [non-classical monocyte](/details-cell/CL0000875) expresses key molecules for interacting with the immune system. The high specificity of [B2M](/details-gene/567) (Beta-2-microglobulin) and the non-classical MHC class I molecule [HLA E](/details-gene/3133) points to a role in antigen presentation, potentially interacting with NK cells or specific T cell subsets. Furthermore, the expression of crucial signaling adaptors like [TYROBP](/details-gene/7305) (DAP12) and [FCER1G](/details-gene/2207) indicates its preparedness to respond to stimuli via various activating receptors. * **Cytoskeletal Dynamics and Motility:** The specific expression of genes like [MYL6](/details-gene/4637) (myosin light chain 6) and [CFL1](/details-gene/1072) (cofilin 1) highlights the importance of the actin cytoskeleton. These proteins are fundamental for cell motility, adhesion, and morphological changes required for intravascular crawling and tissue extravasation. **Overall**, the anti-marker profile helps to further refine the cell's identity. The low significance of transcription factors essential for other myeloid lineages, such as [BATF3](/details-gene/55509) (a key regulator for cDC1 dendritic cells), confirms its distinct developmental trajectory. Similarly, the negative CSI values for genes involved in RNA processing like [DDX17](/details-gene/10521) and [PNISR](/details-gene/25957) may suggest a unique, streamlined post-transcriptional landscape tailored to its specific functions. ## Clinical Significance and Contextual Roles Although this analysis is based on a general **Overall** context, the unique gene signature of [non-classical monocytes](/details-cell/CL0000875) suggests potential involvement in several pathological processes. The profound signature of iron metabolism ([FTL](/details-gene/2512), [FTH1](/details-gene/2495)) implicates these cells in diseases characterized by iron dysregulation and oxidative stress, such as atherosclerosis, where they may contribute to plaque formation or stability by managing local iron concentrations. Their high metabolic rate could also render them particularly important or vulnerable in metabolic disorders. The expression of key immune signaling molecules ([TYROBP](/details-gene/7305), [FCER1G](/details-gene/2207), [LST1](/details-gene/7940)) positions them as active participants in inflammatory and autoimmune diseases. Their patrolling nature allows them to serve as first responders to vascular injury or inflammation, potentially initiating or amplifying immune responses. Notably, the gene [ITM2B](/details-gene/9445) is a highly specific marker. Mutations in this gene are known to cause familial British and Danish dementias, which are characterized by cerebral amyloid angiopathy ([Link](https://doi.org/10.1038/21637)). The specific expression of [ITM2B](/details-gene/9445) in [non-classical monocytes](/details-cell/CL0000875) suggests these cells could play a role in the processing of amyloidogenic peptides or in the inflammatory response associated with neurodegenerative diseases involving vascular pathology. ## Potential Mechanisms and Research Directions 1. **Hypothesis: [Non-classical monocytes](/details-cell/CL0000875) function as intravascular iron scavengers, actively protecting the endothelium from oxidative damage.** * **Surprising Findings:** The expression specificity of iron-storage genes [FTL](/details-gene/2512) and [FTH1](/details-gene/2495) exceeds that of many canonical immune-related genes. This suggests that iron management may be a primary, defining function of this cell type, rather than an ancillary one. * **Testable Questions:** In a mouse model of vascular inflammation, does the specific deletion of [Fth1](/details-gene/2495) in Ly6C-low monocytes lead to increased markers of endothelial oxidative stress and dysfunction compared to wild-type controls? 2. **Hypothesis: The uniquely high expression of regulators of polyamine metabolism, [OAZ1](/details-gene/4946) and [SAT1](/details-gene/6303), provides a metabolic rheostat that controls the activation threshold and lifespan of patrolling monocytes to ensure vascular surveillance without promoting excessive inflammation.** * **Surprising Findings:** It is unusual for genes involved in polyamine regulation, often associated with cell proliferation, to be such specific markers for a relatively quiescent, terminally differentiated immune cell. This points toward a novel, non-proliferative role for polyamine flux in regulating the cell's homeostatic patrolling behavior. * **Testable Questions:** Does pharmacological inhibition of polyamine biosynthesis in vivo alter the residency time, patrolling velocity, or inflammatory cytokine production of [non-classical monocytes](/details-cell/CL0000875) in response to a sterile inflammatory stimulus like LPS?