Details for: CL0000940

Cell ID: CL0000940

Cell Name: mucosal invariant T cell

Description: An alpha-beta T cell that is found in the lamina propria of mucosal tissues and is restricted by the MR-1 molecule. This cell develops from double-positive, alpha-beta thymocyte.

Synonyms: mucosal invariant T cell, mucosal invariant T lymphocyte, mucosal invariant T-cell, mucosal invariant T-lymphocyte, mucosal-associated invariant T lymphocyte, mucosal-associated invariant T-cell, mucosal-associated invariant T-lymphocyte, MAIT

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 mucosal invariant T 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 mucosal invariant T 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 mucosal invariant T 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 mucosal invariant T 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:  mucosal invariant T cell (CL0000940)

 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.

Loading network (please wait)...

## Summary The [mucosal invariant T cell](/details-cell/CL0000940) (MAIT cell) is a specialized alpha-beta [T cell](/details-cell/CL0000084) found predominantly in mucosal tissues, where it recognizes microbial metabolites presented by the non-classical MHC class I-related molecule, MR1. The gene significance profile of MAIT cells underscores a state of high metabolic readiness and a profound involvement in antigen presentation and immune regulation. **Overall**, the top-ranking specific markers, including the non-classical class I molecule [HLA E](/details-gene/3133) and its essential component [B2M](/details-gene/567), suggest a complex role beyond direct T-cell receptor engagement, potentially involving extensive cross-talk with other innate and adaptive immune cells. This is complemented by a strong signature of genes involved in energy production and protein synthesis, indicating these cells are poised for rapid and robust effector functions. ## Key Characteristics and Function The gene expression landscape of [mucosal invariant T cells](/details-cell/CL0000940) points to a cell with a high basal level of activity, primed for immediate immunological responses. The functions can be grouped into several key biological themes based on their most specific gene markers. * **Antigen Presentation and Immune Regulation:** The most striking feature is the extremely high specificity score for components of the MHC class I pathway. [HLA E](/details-gene/3133) (CSI 116.60) and Beta-2-microglobulin ([B2M](/details-gene/567), CSI 113.68) are the top defining markers. While MAIT cells are defined by their MR1-restriction, the prominent expression of [HLA E](/details-gene/3133), a molecule that interacts with both activating and inhibitory receptors (NKG2A/C) on [NK cells](/details-cell/CL0000623) and some [T cells](/details-cell/CL0000084), suggests a critical role in regulating the activity of these other lymphocytes. This indicates MAIT cells may function not only as direct effectors but also as modulators of the broader immune microenvironment. * **High Metabolic Rate and Energy Production:** A large cluster of top markers are components of the mitochondrial electron transport chain, highlighting a high demand for oxidative phosphorylation. These include multiple subunits of cytochrome c oxidase ([COX1](/details-gene/4512), [COX2](/details-gene/4513), [COX7C](/details-gene/1350), [COX4I1](/details-gene/1327)) and cytochrome b ([CYTB](/details-gene/4519)), as well as a subunit of ATP synthase ([ATP5F1E](/details-gene/514)). This pronounced metabolic signature is consistent with the known "innate-like" properties of MAIT cells, which can be activated rapidly to deploy effector functions without the extensive clonal expansion and differentiation required by conventional [T cells](/details-cell/CL0000084). * **Active Protein Synthesis and Cellular Housekeeping:** The cell's preparedness is further supported by high expression of genes essential for protein synthesis, such as translation elongation factors ([EEF1D](/details-gene/1936), [EEF1B2](/details-gene/1933)) and poly(A) binding protein ([PABPC1](/details-gene/26986)). Genes like [TPT1](/details-gene/7178) and the nucleolar phosphoprotein [NPM1](/details-gene/4869) further underscore a state of high biosynthetic capacity, likely to support rapid production of cytokines and cytotoxic molecules upon activation. * **Cytoskeletal Dynamics and Signaling:** Key genes involved in regulating the actin cytoskeleton ([CFL1](/details-gene/1072)) and cellular contractility ([MYL12A](/details-gene/10627)) are highly specific markers. This suggests active cell motility and the capacity to form stable immune synapses. The expression of calcium-binding proteins like [CALM1](/details-gene/801) and [S100A6](/details-gene/6277) points to the importance of calcium signaling pathways in orchestrating MAIT cell activation and function. The anti-marker profile shows a notable negative significance score for [CALM2](/details-gene/805) (CSI -35.35), which is intriguing given that [CALM1](/details-gene/801) is a top positive marker. This suggests a specific reliance on one calmodulin isoform over another, which may fine-tune their unique calcium signaling responses. ## Clinical Significance and Contextual Roles Although this analysis is based on an **Overall** context without a direct disease comparison, the fundamental characteristics of [mucosal invariant T cells](/details-cell/CL0000940) highlighted by their gene signature have significant clinical implications. Their location in mucosal tissues and their potent, pre-programmed metabolic and biosynthetic state position them as critical first-responders to a wide array of bacterial and fungal pathogens that produce the riboflavin-based metabolites recognized by the MAIT cell TCR. Their ability to rapidly produce inflammatory cytokines like IFN-gamma and TNF-alpha, as well as cytotoxic molecules, makes them key players in antimicrobial immunity at barrier surfaces. The uniquely high expression of [HLA E](/details-gene/3133) may be of particular importance. In viral infections, classical HLA molecules are often downregulated to evade conventional [T cell](/details-cell/CL0000084) detection, but [HLA E](/details-gene/3133) expression can be maintained or even induced, serving as a signal to inhibit [NK cell](/details-cell/CL0000623)-mediated killing. MAIT cells, by expressing high levels of [HLA E](/details-gene/3133), might use this pathway to modulate [NK cell](/details-cell/CL0000623) activity during polymicrobial infections, potentially preventing excessive tissue damage. Conversely, this interaction could be co-opted in chronic inflammatory diseases or cancer to either suppress or promote inflammatory responses. The antiproliferative gene [BTG1](/details-gene/694) being a significant marker is also notable, suggesting tight regulation of their expansion ([Link](https://doi.org/10.1002/j.1460-2075.1992.tb05213.x)). Dysregulation of this balance could contribute to autoimmune conditions or an inability to control infections. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The highly specific expression of the non-classical MHC molecule [HLA E](/details-gene/3133) by MAIT cells is not primarily for self-antigen presentation but serves as a key immunoregulatory hub, allowing MAIT cells to directly modulate the activity of NK cells and other innate lymphocytes at mucosal surfaces. * **Surprising Findings:** The most specific gene marker for this T cell subset is not a component of its unique MR1-TCR axis but rather [HLA E](/details-gene/3133), a ligand for NK cell receptors. This prioritizes its regulatory interactions as a defining feature of its identity. * **Testable Questions:** In a co-culture system, does the activation state of [NK cells](/details-cell/CL0000623) (measured by CD107a degranulation and IFN-gamma production) change in response to MR1-activated MAIT cells? Is this change dependent on a direct interaction that can be blocked by antibodies against [HLA E](/details-gene/3133) or its receptor, NKG2A/C? 2. **Hypothesis:** The constitutive high expression of specific mitochondrial respiratory chain subunits ([COX1](/details-gene/4512), [COX2](/details-gene/4513)) alongside the relative underexpression of others (e.g., [NDUFA4](/details-gene/4697), [COX5B](/details-gene/1329)) reflects a pre-wired metabolic configuration that enables the rapid, "innate-like" effector functions of MAIT cells, distinguishing them from the inducible metabolic reprogramming of conventional T cells. * **Surprising Findings:** Rather than a uniform upregulation of all metabolic genes, MAIT cells exhibit a highly specific and complex pattern of both positive and negative markers within the mitochondrial proteome. Furthermore, the preferential expression of [CALM1](/details-gene/801) over [CALM2](/details-gene/805) suggests a distinct isoform usage that could be linked to the fine-tuning of this unique metabolic state via calcium-dependent signaling. * **Testable Questions:** Does metabolic flux analysis of resting MAIT cells reveal a higher basal oxidative phosphorylation rate compared to naive conventional [CD8+ T cells](/details-cell/CL0000625)? Following activation with an MR1 agonist, do MAIT cells exhibit a faster ramp-up of effector functions (e.g., cytokine secretion) with less reliance on glycolysis compared to TCR-stimulated conventional T cells?