Details for: CL0000819

Cell ID: CL0000819

Cell Name: B-1 B cell

Description: There are small numbers of B-1 cells found in the lymph nodes and spleen, while larger numbers can be found in the peritoneal and pleural cavities. B-1 B cells are reportedly CD11b-positive, CD20-positive, CD21-positive, CD27-positive, CD44-positive, CD45RB-positive, CD48-positive, CD70-negative, CD150-positive, CD244-negative, CD352-positive, sIgM-positive, and sIgD-low.

Synonyms: B-1 B lymphocyte, B-1 B-cell, B-1 B-lymphocyte, B-1 cell, B1 B cell, B1 B lymphocyte, B1 B-cell, B1 B-lymphocyte, B1 cell

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 B-1 B 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 B-1 B 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 B-1 B 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 B-1 B 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:  B-1 B cell (CL0000819)

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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 [B-1 B cell](/details-cell/CL0000819) is a distinct subset of B lymphocytes primarily located in the peritoneal and pleural cavities. Based on its gene significance profile, this cell type appears to be characterized less by unique cell surface immune receptors and more by an exceptionally high level of core cellular machinery. The top markers, identified by expression specificity (`csi_z`), are overwhelmingly involved in mitochondrial energy production, ribosome biogenesis, and protein translation. This molecular signature suggests a cell constitutively primed for high metabolic output and protein synthesis, which is consistent with its known role in producing natural antibodies as part of the innate-like immune system. ## Key Characteristics and Function An analysis of the top marker genes for the [B-1 B cell](/details-cell/CL0000819) in the **Overall** context reveals a profile dominated by fundamental biological processes, suggesting a state of high basal activity. These markers can be grouped into several key functional clusters: * **Mitochondrial Energy Metabolism:** A prominent group of genes with high expression specificity is associated with oxidative phosphorylation. This includes multiple subunits of ATP synthase ([ATP5MC2](/details-gene/517), [ATP5F1E](/details-gene/514)) and cytochrome c oxidase ([COX7C](/details-gene/1350), [COX4I1](/details-gene/1327)), as well as other components of the respiratory chain like [UQCRB](/details-gene/7381) and the mitochondrial transporter [SLC25A6](/details-gene/293). This robust signature points to a high demand for ATP, likely fueling continuous protein production and maintenance. * **Protein Synthesis and Processing:** The cell is distinguished by high expression of genes central to the synthesis of proteins. This includes the general transcription factor [BTF3](/details-gene/689) ([Link](https://pubmed.ncbi.nlm.nih.gov/2320128/)), the nucleolar protein [NPM1](/details-gene/4869) involved in ribosome biogenesis ([Link](https://doi.org/10.1021/bi00429a017)), and translation elongation factors [EEF1D](/details-gene/1936) and [EEF1B2](/details-gene/1933). Furthermore, a suite of RNA-binding proteins, including [PCBP2](/details-gene/5094), [HNRNPA2B1](/details-gene/3181), and [HNRNPA1](/details-gene/3178), have high significance, underscoring the importance of post-transcriptional regulation and mRNA processing. * **Antigen Presentation and Cytoskeletal Structure:** The high significance of [B2M](/details-gene/567), a key component of MHC class I molecules, highlights the cell's capacity for antigen presentation and interaction with other immune cells. Genes involved in cytoskeletal organization, such as [CFL1](/details-gene/1072) and [MYL6](/details-gene/4637), suggest the maintenance of cellular structure and potential for motility. Notably, the anti-marker list provides critical context for what this cell is not defined by in this analysis. The low significance scores for canonical B-cell lineage and signaling genes such as [CD79A](/details-cell/973) (a B-cell receptor component), [CD22](/details-gene/933), the tyrosine kinase [BLK](/details-gene/640), and the B-cell coactivator [POU2AF1](/details-gene/5450) is unexpected. This suggests that while these genes are present, their expression is not uniquely high in [B-1 B cells](/details-cell/CL0000819) compared to other cell types in this dataset. This finding indicates that the cell's defining characteristic at the transcriptomic level is its metabolic and biosynthetic "engine" rather than its specific antigen receptor complex. The low significance of [CD70](/details-gene/970) is consistent with the cell's formal description as being CD70-negative. ## Clinical Significance and Contextual Roles The gene signature of the [B-1 B cell](/details-cell/CL0000819) suggests a cell in a state of constant readiness and functional output, a hallmark of innate-like lymphocytes. Its heavy reliance on oxidative phosphorylation could render it susceptible to metabolic perturbations or targeted therapies aimed at mitochondrial function. The high specificity of [NPM1](/details-gene/4869), a gene frequently mutated in hematopoietic malignancies, may be of clinical interest. While mutations are most associated with myeloid leukemia, the pronounced expression in this B-cell subset could have implications for its role in B-cell lymphomagenesis, particularly in chronic lymphocytic leukemia (CLL), which is often considered a malignancy of a B-1-like cell. The overall profile, emphasizing a powerful "housekeeping" infrastructure over specialized signaling components, supports the role of [B-1 B cells](/details-cell/CL0000819) in providing a first line of defense through the constitutive secretion of natural IgM. These antibodies are crucial for clearing apoptotic debris and providing immediate, broad-spectrum protection against common pathogens. The cell's molecular identity appears hard-wired for this persistent function, differing from the inducible, adaptive responses of conventional B-cells. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The defining transcriptional identity of the [B-1 B cell](/details-cell/CL0000819) is primarily established by a stable, constitutively active metabolic and protein synthesis program, which underpins its innate-like function of persistent natural antibody production. This contrasts with conventional B-cells, whose identity is more dynamically shaped by B-cell receptor signaling. * **Surprising Findings:** Key components of the B-cell receptor signaling pathway, such as [CD79A](/details-gene/973), [BLK](/details-gene/640), and [CD22](/details-gene/933), are not among the top markers of specificity. Instead, the most defining genes are related to core energetic and biosynthetic processes. * **Testable Questions:** How does the rate of immunoglobulin secretion and overall protein synthesis in [B-1 B cells](/details-cell/CL0000819) change in response to metabolic inhibitors targeting oxidative phosphorylation (e.g., oligomycin) or glycolysis (e.g., 2-DG), and how does this compare to the response of follicular [B-cells](/details-cell/CL0000847)? 2. **Hypothesis:** The specific expression profile of [B-1 B cells](/details-cell/CL0000819) is maintained by a unique landscape of transcriptional regulators and chromatin states that lock the cell into a high-activity mode. General factors like [BTF3](/details-gene/689) and a suite of HNRNP proteins may play a more critical role in defining this cell's state than lineage-specific transcription factors that respond to external signals. * **Surprising Findings:** A basic transcription factor, [BTF3](/details-gene/689), and several RNA-binding proteins emerge as top specific markers, suggesting that the regulation of the central dogma itself is a key specialization of this cell type. * **Testable Questions:** Does a comparative analysis of chromatin accessibility (e.g., ATAC-seq) reveal that the gene loci for top metabolic ([ATP5MC2](/details-gene/517), [COX7C](/details-gene/1350)) and ribosomal ([NPM1](/details-gene/4869)) markers in [B-1 B cells](/details-cell/CL0000819) are constitutively more open than in conventional [B-2 B cells](/details-cell/CL0000816), indicating a pre-programmed state of high expression?