Details for: CL0000987

Cell ID: CL0000987

Cell Name: IgA plasma cell

Description: A fully differentiated plasma cell that secretes IgA.

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 IgA plasma 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 IgA plasma 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 IgA plasma 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 IgA plasma 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:  IgA plasma cell (CL0000987)

 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 [IgA plasma cell](/details-cell/CL0000987) is a terminally differentiated B-lymphocyte lineage cell whose primary function is the large-scale production and secretion of Immunoglobulin A (IgA). The gene significance profile for this cell type underscores its role as a professional secretory cell, characterized by an exceptionally high metabolic rate and a robustly engaged protein synthesis and quality control apparatus. The most defining marker, [HERPUD1](/details-gene/9709), is an integral component of the endoplasmic reticulum (ER) stress response, suggesting that managing the immense proteotoxic stress from massive IgA synthesis is a key aspect of this cell's unique biological identity. ## Key Characteristics and Function **Overall**, the gene expression signature of the [IgA plasma cell](/details-cell/CL0000987) paints a vivid picture of a cell singularly focused on high-volume protein production. The top markers can be grouped into several key functional clusters that collectively enable this demanding physiological role. * **Protein Synthesis, Folding, and Secretion:** The cell's identity is dominated by genes involved in the secretory pathway. The top marker, [HERPUD1](/details-gene/9709), is induced by the unfolded protein response (UPR) and ER stress, a state inherent to professional secretory cells ([Link](https://doi.org/10.1074/jbc.m002063200)). This is complemented by high significance scores for genes involved in protein translation, such as elongation factors [EEF1D](/details-gene/1936) and [EEF1B2](/details-gene/1933), and protein N-linked glycosylation, such as [OST4](/details-gene/100128731). The high significance of the transcription factor [JUN](/details-gene/3725), a component of the AP-1 complex, may also relate to cellular responses to the stress of high metabolic and synthetic activity. * **High Metabolic Activity and Energy Production:** Sustaining such a high rate of protein synthesis requires a vast energy supply. This is reflected in the strong significance of numerous nuclear-encoded mitochondrial genes involved in oxidative phosphorylation. These include components of the cytochrome c oxidase complex ([COX1](/details-gene/4512), [COX2](/details-gene/4513)), ATP synthase ([ATP5MG](/details-gene/10632), [ATP5F1E](/details-gene/514)), and the NADH dehydrogenase complex ([ND2](/details-gene/4536), [ND4](/details-gene/4538)). The high significance of [SLC25A6](/details-gene/293), an ADP/ATP translocase, further emphasizes the critical role of mitochondrial ATP export to fuel cytoplasmic processes. * **Protein Quality Control and Turnover:** A high rate of protein synthesis inevitably leads to misfolded products that must be cleared. The high significance of ubiquitin genes [UBC](/details-gene/7316) and [UBB](/details-gene/7314) points to a highly active ubiquitin-proteasome system essential for maintaining protein homeostasis and cell viability. * **Immune Function and General Homeostasis:** The strong signature of [B2M](/details-gene/567) indicates active MHC class I antigen presentation, allowing the cell to communicate its internal state to the adaptive immune system, particularly cytotoxic T-lymphocytes. The significance of [FTL](/details-gene/2512) suggests a robust system for managing iron, an essential cofactor for the high-energy metabolic pathways central to the cell's function. The anti-marker profile is also informative. The low specificity scores (CSI Z-Score) for several immunoglobulin variable chain genes (e.g., [IGLV2 8](/details-gene/28817), [IGKV1D 12](/details-gene/28903)) do not indicate a lack of expression. Instead, given their high effect sizes, this suggests that while these genes are abundantly expressed, their expression is not unique to this terminal differentiation state compared to other B-lineage cells. Therefore, they are not specific *defining* markers for the [IgA plasma cell](/details-cell/CL0000987) in a comparative context. ## Clinical Significance and Contextual Roles The gene signature of the [IgA plasma cell](/details-cell/CL0000987) provides insight into its potential roles in disease, particularly in plasma cell dyscrasias like multiple myeloma. The dependency on pathways managing proteotoxic stress and high metabolic output represents a potential vulnerability. The prominence of [HERPUD1](/details-gene/9709) and other UPR-related genes highlights the cell's reliance on the ER stress response for survival. This pathway is a known therapeutic target in multiple myeloma, where malignant plasma cells are exquisitely sensitive to inhibitors of protein degradation and folding. Furthermore, the high level of [B2M](/details-gene/567) is a well-established negative prognostic marker in multiple myeloma, where its serum levels correlate with tumor burden and disease activity. The proto-oncogene [JUN](/details-gene/3725) is a key regulator of cell proliferation, differentiation, and apoptosis. Its specific role in terminally differentiated, non-proliferating plasma cells is intriguing and may relate to survival signaling. The significant expression of detoxification genes like [GSTP1](/details-gene/2950) suggests a capacity to handle oxidative stress, which could contribute to the cell's longevity and resilience in inflammatory microenvironments. Dysregulation of these survival and stress-response pathways is likely a key step in the malignant transformation of plasma cells. ## Potential Mechanisms and Research Directions 1. **Hypothesis: The Unfolded Protein Response (UPR) as a Core Functional Program.** The data suggests that the UPR in IgA plasma cells is not merely a transient stress response but a constitutively active and essential program for managing the physiological proteotoxic stress of high-volume IgA secretion. The high specificity of [HERPUD1](/details-gene/9709), an ER stress-inducible gene ([Link](https://doi.org/10.1074/jbc.m002063200)), supports the idea that this pathway is a central, defining feature of the cell's identity. * **Surprising Findings:** The most specific marker defining an [IgA plasma cell](/details-cell/CL0000987) is not an immunoglobulin-related gene, but a component of the ER stress machinery. This reframes the cell's identity, emphasizing that the *management* of antibody secretion, rather than the antibody genes themselves, is what most uniquely distinguishes its transcriptional state. * **Testable Questions:** Does the targeted inhibition of the ATF6 pathway, a key transcriptional regulator of [HERPUD1](/details-gene/9709) ([Link](https://doi.org/10.1074/jbc.m010486200)), lead to a more profound reduction in viability and IgA secretion in [IgA plasma cells](/details-cell/CL0000987) compared to other secretory cell types, such as pancreatic acinar cells? 2. **Hypothesis: Critical Dependence on Specialized Mitochondrial Metabolism.** The strong and specific signature of multiple nuclear-encoded genes for oxidative phosphorylation subunits (e.g., [COX1](/details-gene/4512), [ATP5MG](/details-gene/10632), [ND4](/details-gene/4538)) suggests that IgA plasma cells undergo profound metabolic reprogramming towards a state of high mitochondrial respiration. This state may be critical not only for ATP production but also for generating metabolic intermediates required for the extensive post-translational modification, such as glycosylation, of IgA molecules. * **Surprising Findings:** It is not just one or two metabolic genes, but a broad suite of components from multiple complexes of the electron transport chain that are significant markers. This points towards a highly coordinated and specific upregulation of the entire oxidative phosphorylation apparatus, suggesting a specialized metabolic phenotype rather than a generic increase in metabolism. * **Testable Questions:** How do mitochondrial inhibitors that selectively target different respiratory complexes (e.g., rotenone for Complex I, antimycin A for Complex III) affect the specific glycosylation patterns and secretion kinetics of IgA, and can these effects be uncoupled from simple ATP depletion?