Details for: IGKV1 9

Gene ID: 28941

Gene Type:  Other  - A known gene or region type that lacks a specific category. Includes immunoglobulin (Ig), T-cell receptor (TCR) gene segments, and repetitive elements.

Symbol: IGKV1 9

Ensembl ID: ENSG00000241755

Description: immunoglobulin kappa variable 1-9

Selected Context(s):  Overall

Cell Significance Landscape

Contexts:

Associated with

Significant Cells

Cell Significance Index (CSI) scores for the chosen context(s)

  • IgA plasma cell CL0000987
    CSI 3.32
    rCSI 3.4%
    PRS 96.55
  • plasmablast CL0000980
    CSI 2.98
    rCSI 2.34%
    PRS 98.03
  • IgG plasma cell CL0000985
    CSI 2.63
    rCSI 3.15%
    PRS 97.96

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this specific cell.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.
Network Configuration

Explore relationships of the current gene. Select an Interaction Source: 'ONTOLOGY' for shared pathways (GO/Reactome) or 'STRING' for protein-protein interactions. Further refine by selecting context genes and comparing Cell Significance Index (CSI) scores between baseline and target cell types and their specific contexts.

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  • Node Color (Target Cell CSI, relative to current network):
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    • High
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    • CSI N/A
  • Node Size: Proportional to Target Cell CSI magnitude
  • STRING PPI Edge
  • Shared Pathway Edge (ONTOLOGY)

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Other Information

This section provides additional information about the gene, including a description generated by an AI language model and details about associated proteins.

## Summary [IGKV1 9](/details-gene/28941) is a gene segment encoding the variable (V) region of an immunoglobulin kappa light chain. As a fundamental component of the adaptive immune system, it contributes to the vast diversity of antigen-binding sites on antibodies. Its expression is highly specific to the B-cell lineage, with particularly high significance in terminally differentiated, antibody-secreting cells. **Overall**, the data strongly indicates that [IGKV1 9](/details-gene/28941) is a key marker for [plasmablasts](/details-cell/CL0000980) and [plasma cells](/details-cell/CL0000987), reflecting its central role in humoral immunity. ## Cellular Roles and Expression Landscape The expression profile of [IGKV1 9](/details-gene/28941) underscores its specialized function within the immune system. The gene shows its highest significance in cells responsible for antibody production, including [IgA plasma cells](/details-cell/CL0000987) (CSI: 3.32), [plasmablasts](/details-cell/CL0000980) (CSI: 2.98), and [IgG plasma cells](/details-cell/CL0000985) (CSI: 2.63). This pattern suggests that the transcription of the [IGKV1 9](/details-gene/28941) segment is a defining characteristic of mature B-lymphocytes that have undergone differentiation into professional secretory cells. Its prominent role in both IgA- and IgG-producing plasma cells indicates its use across different antibody isotypes, contributing to mucosal and systemic immunity, respectively. The data points to a highly restricted expression pattern, consistent with a specialized role exclusively within the B-cell lineage during the final stages of humoral immune responses. ## Pathways and Molecular Function Functionally, [IGKV1 9](/details-gene/28941) is integral to the biological process of the [adaptive immune response](/details-ontologies/GO:0002250) and the broader [immune response](/details-ontologies/GO:0006955). The protein segment encoded by this gene is a critical component of the [immunoglobulin complex](/details-ontologies/GO:0019814), which forms the B-cell receptor on the cell surface or is secreted as an antibody. As part of this complex, it is localized to the [plasma membrane](/details-ontologies/GO:0005886) in B-cells and plasmablasts before the final secreted form is produced by plasma cells. The V(D)J recombination process, which incorporates gene segments like [IGKV1 9](/details-gene/28941), is the molecular mechanism responsible for generating the diversity required for recognizing a nearly infinite array of foreign antigens. ## Research Directions The specific and high-level expression of [IGKV1 9](/details-gene/28941) in antibody-secreting cells provides a strong foundation for further investigation into its role in both normal and pathological immune responses. **Proposed Hypotheses:** 1. The utilization of the [IGKV1 9](/details-gene/28941) gene segment may be preferentially selected for during immune responses against specific classes of pathogens (e.g., encapsulated bacteria or particular viral glycoproteins), leading to its enrichment in the memory B-cell and plasma cell pools of exposed individuals. 2. In B-cell malignancies such as multiple myeloma or certain lymphomas, clonal expansion of malignant cells may lead to an over-representation of [IGKV1 9](/details-gene/28941) expression, potentially serving as a clonal marker to track minimal residual disease. **Experimental Approach:** To test the hypothesis that [IGKV1 9](/details-gene/28941) can serve as a clonal marker in multiple myeloma, a compelling approach would be to perform deep single-cell V(D)J sequencing combined with single-cell RNA sequencing (scRNA-seq) on bone marrow aspirates from a cohort of patients. This dual analysis would allow for the precise identification of the malignant [plasma cell](/details-cell/CL0000987) clone and the quantification of [IGKV1 9](/details-gene/28941) usage within that clone. Correlating the presence and abundance of this specific V-gene segment with clinical outcomes, treatment responses, and other genomic features of the cancer could establish its utility as a prognostic or monitoring biomarker. **Therapeutic Potential:** As a gene segment, [IGKV1 9](/details-gene/28941) is not a direct therapeutic target. However, its product, as part of a unique antibody idiotype on the surface of a malignant B-cell, represents a highly specific tumor antigen. This makes it an attractive target for personalized immunotherapy. If a patient's cancerous clone is defined by the use of [IGKV1 9](/details-gene/28941), therapies such as anti-idiotype antibodies or Chimeric Antigen Receptor (CAR)-T cells engineered to recognize this specific idiotype could be developed to eradicate malignant cells with high precision, potentially sparing healthy tissues.