Details for: CL0000863

Cell ID: CL0000863

Cell Name: inflammatory macrophage

Description: Markers: Express: TNFa, IL1b, IL6, iNOS, NADPH-oxidase; produce: reactive oxygen species, nitric oxide; role or process: immune, inflammation (inflammatory response).

Synonyms: inflammatory macrophage, classically activated macrophage

Selected Context(s): Overall

Gene Significance Landscape

Display Options
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 inflammatory macrophage 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 inflammatory macrophage. 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 inflammatory macrophage. 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 inflammatory macrophage. 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:  inflammatory macrophage (CL0000863)

 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 An [inflammatory macrophage](/details-cell/CL0000863), also known as a classically activated macrophage, is a key effector cell of the innate immune system, characterized by its production of pro-inflammatory cytokines such as TNFa, IL-1b, and IL-6. The **Overall** gene significance profile strongly supports this role, highlighting a cell type specialized in antigen presentation, iron metabolism, and robust immune activation. The top defining marker, [B2M](/details-gene/567) (Beta-2-microglobulin), underscores its critical function in presenting endogenous antigens via MHC class I complexes. Furthermore, the high specificity of ferritin genes ([FTL](/details-gene/2512), [FTH1](/details-gene/2495)) and polyamine metabolism regulators ([SAT1](/details-gene/6303)) suggests that metabolic control is a central, defining feature of its inflammatory state. ## Key Characteristics and Function The gene expression signature of the [inflammatory macrophage](/details-cell/CL0000863) points towards a multifaceted role in host defense and inflammation, organized around several key functional clusters. * **Antigen Presentation and Immune Receptor Signaling:** The cell is strongly geared for immune surveillance and T-cell activation. The most specific marker is [B2M](/details-gene/567), an essential component of MHC class I molecules. This is complemented by the expression of [HLA-DPA1](/details-gene/3113), a component of the MHC class II complex, indicating a capacity to present both endogenous and exogenous antigens. The high significance of [PTPRC](/details-gene/5788) (CD45) points to its hematopoietic origin and active signal transduction. Furthermore, significant expression of adapter proteins like [TYROBP](/details-gene/7305) (DAP12) and [FCER1G](/details-gene/2207) (Fc receptor gamma chain) suggests the cell integrates signals from a wide array of activating receptors, including killer cell immunoglobulin-like receptors and Fc receptors, to mount a robust immune response [Link](https://doi.org/10.1038/35642). * **Iron Sequestration and Metabolism:** A defining feature is the highly specific expression of both the light ([FTL](/details-gene/2512)) and heavy ([FTH1](/details-gene/2495)) chains of ferritin. This highlights the central role of iron metabolism in these cells, likely as a host defense mechanism to limit iron availability for invading pathogens (nutritional immunity) and to manage oxidative stress generated during the inflammatory response. * **Polyamine Metabolism Regulation:** The high `csi_z` score for [SAT1](/details-gene/6303) (spermidine/spermine N1-acetyltransferase) is particularly noteworthy. [SAT1](/details-gene/6303) is the rate-limiting enzyme in polyamine catabolism. Its high expression, along with that of [OAZ1](/details-gene/4946) (ornithine decarboxylase antizyme), suggests that tight regulation of intracellular polyamine levels is a critical aspect of the inflammatory macrophage phenotype, influencing processes from inflammation to cell proliferation. * **Innate Immune Effector Functions:** The significance of complement components [C1QA](/details-gene/712) and [C1QB](/details-gene/713) indicates an active role in initiating the classical complement cascade, a crucial bridge between innate and adaptive immunity. Genes associated with cytoskeletal dynamics and phagocytosis, such as [AIF1](/details-gene/199) and [LSP1](/details-gene/4046), support the cell's primary function as a professional phagocyte. * **Transcriptional and Metabolic State:** The negative significance scores for several heterogeneous nuclear ribonucleoproteins (e.g., [HNRNPU](/details-gene/3192), [HNRNPC](/details-gene/3183)) and splicing factors ([SRSF5](/details-gene/6430)) may indicate a specialized post-transcriptional landscape tailored to produce inflammatory mediators. The low scores for specific cytochrome c oxidase subunits like [COX7C](/details-gene/1350) could suggest a metabolic shift away from oxidative phosphorylation towards glycolysis (the Warburg effect), a known feature of classically activated macrophages. ## Clinical Significance and Contextual Roles **Overall**, the [inflammatory macrophage](/details-cell/CL0000863) is a central player in both protective immunity and immunopathology. Its gene signature is implicated in a variety of clinical contexts. The strong expression of antigen-presenting machinery ([B2M](/details-gene/567), [HLA-DPA1](/details-gene/3113)) and leukocyte-specific signaling molecules ([PTPRC](/details-gene/5788), [TYROBP](/details-gene/7305)) establishes its fundamental role in orchestrating adaptive immune responses. The prominent role of [AIF1](/details-gene/199), an allograft inflammatory factor, links this cell type directly to transplant rejection and tissue injury responses [Link](https://doi.org/10.1006/bbrc.1996.1612). Furthermore, the expression of the chemokine receptor [CXCR4](/details-gene/7852) highlights its capacity for migration to sites of inflammation and its potential involvement in viral pathogenesis, as [CXCR4](/details-gene/7852) is a known co-receptor for HIV entry. The profound signature of iron metabolism ([FTL](/details-gene/2512), [FTH1](/details-gene/2495)) is clinically relevant to the anemia of chronic disease, where inflammatory cytokine-driven iron sequestration by macrophages restricts iron availability for erythropoiesis. Dysregulation of this axis can contribute to both chronic inflammation and susceptibility to infection. The complement proteins [C1QA](/details-gene/712) and [C1QB](/details-gene/713) are associated with autoimmune diseases like systemic lupus erythematosus, where their deficiency can impair the clearance of apoptotic cells and immune complexes, further implicating these cells in autoimmune pathology. ## Potential Mechanisms and Research Directions 1. **Hypothesis: Polyamine catabolism, driven by [SAT1](/details-gene/6303), is a key regulatory node that defines the functional state of inflammatory macrophages.** * **Surprising Findings:** While pro-inflammatory stimuli are known to modulate polyamine synthesis, the data highlights the catabolic enzyme [SAT1](/details-gene/6303) as one of the most uniquely specific markers for this cell type. This suggests that the *breakdown* of polyamines, rather than their synthesis, may be a more critical and defining checkpoint for establishing and maintaining the M1 phenotype. * **Testable Questions:** Does pharmacological or genetic inhibition of [SAT1](/details-gene/6303) in human monocyte-derived macrophages prevent their polarization towards an inflammatory phenotype upon stimulation with IFN-gamma and LPS, as measured by cytokine secretion and surface marker expression? 2. **Hypothesis: The ferritin complex acts as an intracellular signaling platform that integrates iron metabolism with innate immune receptor signaling.** * **Surprising Findings:** The `csi_z` scores for ferritin subunits ([FTL](/details-gene/2512), [FTH1](/details-gene/2495)) are exceptionally high, ranking them among the most specific identifiers of this cell state. This implies their function extends beyond simple iron storage and is more integral to the cell's core identity, potentially acting as a scaffold or regulator for other key immune proteins. * **Testable Questions:** Does altering intracellular iron levels via knockdown of [FTL](/details-gene/2512) or [FTH1](/details-gene/2495) impact the phosphorylation and downstream signaling of the activating adapter [TYROBP](/details-gene/7305) following receptor engagement in [inflammatory macrophages](/details-cell/CL0000863)?