ormdl3 Antibody

What is ORMDL3 and why is it a significant research target?

ORMDL3 is a 153-amino acid transmembrane protein primarily located in the endoplasmic reticulum (ER). It belongs to the three-gene ORMDL family (ORMDL1, ORMDL2, and ORMDL3) . ORMDL3 has gained significant research interest because genetic variants in the ORMDL3 gene are associated with various inflammatory conditions including asthma, inflammatory bowel disease, ankylosing spondylitis, atherosclerosis, systemic lupus erythematosus (SLE), and cholangitis . Recent research has uncovered ORMDL3's role in regulating eosinophil function, sphingolipid synthesis, and inflammatory pathways, making it an important target for immunological and inflammatory disease research .

What types of ORMDL3 antibodies are available for research?

Commercial antibodies against ORMDL3 include polyclonal and monoclonal options with different specificities. It's important to note that some antibodies recognize all ORMDL family members (ORMDL1, ORMDL2, and ORMDL3), while others are more specific to ORMDL3 . When selecting an antibody, researchers should verify specificity using techniques such as Western blotting combined with knockdown or overexpression controls. Available antibodies include those from manufacturers like Abcam (catalog numbers 107639 and 211522), which have been successfully employed in co-immunoprecipitation and immunoblot assays .

What are the common applications of ORMDL3 antibodies in basic research?

ORMDL3 antibodies serve multiple purposes in laboratory investigations:

• Western blotting for protein level quantification

• Immunoprecipitation (IP) for protein-protein interaction studies

• Immunohistochemistry (IHC) for tissue localization

• Proximity ligation assays (PLA) for examining protein-protein proximity

• Flow cytometry for cellular distribution analysis

• Validation of knockdown or overexpression efficiency in experimental models

Researchers often use these antibodies to assess ORMDL3 expression levels in different cellular compartments, particularly in studies investigating ER-mitochondria contacts and inflammasome activation .

How should ORMDL3 antibodies be validated before experimental use?

Proper validation of ORMDL3 antibodies is crucial due to potential cross-reactivity with other ORMDL family members. Recommended validation steps include:

• Confirming specificity using positive controls (ORMDL3 overexpression) and negative controls (ORMDL3 knockdown)

• Verifying antibody performance in relevant experimental conditions

• Complementing antibody-based detection with mRNA analysis using qRT-PCR

• Using multiple antibodies from different clones when possible

• Including appropriate loading controls in Western blots

As noted in the literature, some antibodies recognize all ORMDL family members, necessitating parallel mRNA quantification to specifically measure ORMDL3 levels: "As the ORMDL3 antibody can recognize all ORMDL family members (ORMDL1, 2, and 3), we also detected the mRNA level of ORMDL3 to further validate..." .

How can ORMDL3 antibodies be used to investigate ER-mitochondria contacts?

ORMDL3 antibodies have proven valuable for studying ER-mitochondria contacts, which play critical roles in inflammatory responses. Methodological approaches include:

• Proximity Ligation Assays (PLA): Researchers have successfully employed PLA using antibodies against ER resident protein IP3R1 and mitochondria-specific protein VDAC along with ORMDL3 antibodies to visualize ER-mitochondria contacts. These assays reveal red puncta only after colocalization, providing clear evidence of spatial proximity .

• Immunoelectron Microscopy: This technique allows visualization of ORMDL3 localization to mitochondria-associated membranes (MAMs) and quantification of ER-mitochondria contact points at distances less than 40 nm .

• Co-immunoprecipitation: ORMDL3 antibodies can be used to identify interaction partners at the ER-mitochondria interface, such as the reported interaction with mitochondrial dynamic regulating protein Fis-1 .

Research has demonstrated that "ORMDL3 localizes in the MAM and enhances ER-mitochondria contact formation which might enhance NLRP3 inflammasome activation and IL-1β production" . These techniques provide crucial insights into the molecular mechanisms underlying inflammatory responses in conditions like ulcerative colitis.

What considerations should be made when using ORMDL3 antibodies in inflammasome activation studies?

When investigating ORMDL3's role in inflammasome activation, researchers should consider:

• Stimulus-specific effects: LPS priming followed by different NLRP3 activators (nigericin, MSU, ATP) may produce varying results requiring careful antibody selection and experimental design .

• Time-dependent expression changes: Studies show ORMDL3 upregulation at the mRNA level occurs in a time-dependent manner in response to inflammatory stimuli .

• Cellular compartment specificity: Since ORMDL3 relocates from the ER to mitochondria-associated membranes during inflammation, subcellular fractionation combined with immunoblotting provides more informative results than whole-cell lysate analysis .

• Parallel cytokine measurements: ORMDL3 knockdown significantly reduces IL-1β but has no effect on IL-10 and TNF-α production, demonstrating pathway-specific effects that should be monitored in parallel .

• Combined protein-mRNA analysis: Due to antibody cross-reactivity concerns, researchers should complement protein detection with mRNA analysis using qRT-PCR to confirm ORMDL3-specific effects .

How can ORMDL3 antibodies be effectively used in cancer immunology research?

Recent findings highlight ORMDL3's role in tumor immunity, with antibody applications including:

• Tumor tissue immunohistochemistry: ORMDL3 antibodies have been employed to assess expression in tumor models, with knockdown of ORMDL3 showing enhanced anti-tumor activity .

• Mechanistic studies of interferon signaling: Research demonstrates ORMDL3's negative regulation of RLR-induced type I IFN signaling, where antibody-based detection helps track protein interactions and modifications .

• Correlation with immune cell infiltration: Combined use of ORMDL3 antibodies with CD8+ T cell markers in IHC reveals that ORMDL3 knockdown increases cytotoxic T cell infiltration in tumor models .

The methodological approach typically involves:

• Establishing ORMDL3 knockdown or overexpression tumor models

• Using immunoblotting to validate expression changes

• Performing IHC with ORMDL3 antibodies on tumor sections

• Correlating ORMDL3 expression with immune markers and cytokine levels

• Combining with flow cytometry for immune cell population analysis

Studies have shown: "IHC assays revealed that more CD8+ T cells were infiltrated in ORMDL3 knockdown MC38 tumors," highlighting antibody utility in tracking ORMDL3's impact on tumor immunity .

What technical challenges exist in using ORMDL3 antibodies for co-immunoprecipitation studies?

Co-immunoprecipitation (co-IP) studies with ORMDL3 present several technical challenges:

• Cross-reactivity concerns: Since antibodies may recognize all ORMDL family members, appropriate controls are essential .

• Membrane protein solubilization: As ORMDL3 is a transmembrane protein, optimization of lysis buffers is critical for effective solubilization without disrupting protein-protein interactions.

• Transient interactions: Some ORMDL3 interactions may be stimulus-dependent or transient, requiring crosslinking approaches or stimulus-specific timing.

A recommended protocol based on published research includes:

• Washing cells with cold PBS

• Lysing with 1× lysis buffer (Cell Signaling Technology)

• Incubating on ice for 30 minutes

• Immunoprecipitating with ORMDL3 antibodies for 4 hours at 4°C

• Recovering complexes with protein A/G Sepharose Beads overnight

• Washing beads with buffer before analysis

This approach has successfully identified ORMDL3 interaction partners in mass spectrometry studies using paired flag-vector or flag-ORMDL3 transfected cells for comparison .

How can specificity issues with ORMDL3 antibodies be addressed?

The specificity challenge with ORMDL3 antibodies requires comprehensive validation strategies:

• Genetic controls: Use of ORMDL3 knockout, knockdown, and overexpression systems provides essential validation for antibody specificity .

• Complementary approaches: Combine antibody detection with mRNA quantification through qRT-PCR to distinguish between ORMDL family members .

• Peptide competition: Pre-incubating antibodies with the immunizing peptide can help verify signal specificity.

• Multi-antibody approach: Using multiple antibodies targeting different epitopes of ORMDL3 can increase confidence in results.

• Species-specific validation: When working across species models, verify cross-reactivity and specificity in each species separately.

Studies often employ statements like this to address specificity concerns: "ORMDL3 knockdown efficiency is shown in Fig. S2 B. Furthermore, ORMDL3 overexpression showed high IL-1β secretion from the human MDM cells (Fig. 2 C) validating our patient data. ORMDL3 overexpression efficiency is shown in Fig. S2 A."

What are the optimal conditions for using ORMDL3 antibodies in different subcellular localization studies?

ORMDL3 exhibits dynamic localization in response to inflammatory stimuli, requiring optimized protocols for various cellular compartments:

• ER localization (baseline): Standard immunofluorescence protocols with permeabilization suitable for ER membrane proteins work well for detecting ORMDL3's primary ER localization .

• Mitochondria-associated membrane (inflammatory conditions): During inflammation, ORMDL3 relocates to MAMs, requiring:

  • Careful subcellular fractionation

  • Co-staining with both ER markers and mitochondrial markers

  • Higher antibody concentrations may be needed for detection in MAMs

  • Confocal microscopy with high resolution to distinguish close organelle contacts

• Mitochondrial localization: Detection of ORMDL3 in mitochondria requires:

  • Rigorous mitochondrial isolation procedures

  • Validation with mitochondrial markers

  • Controls to exclude contamination from other organelles

Research has shown that "ORMDL3 that was previously known to be localized in the ER also becomes localized to mitochondria-associated membranes and mitochondria during inflammatory conditions" , highlighting the importance of condition-specific protocols.

What experimental controls are essential when investigating ORMDL3 expression in disease models?

When studying ORMDL3 in disease models, several controls are critical:

• Disease activity stratification: In ulcerative colitis studies, patient samples should be stratified by disease activity, as "a subpopulation of the UC patients who had higher disease activity shows enhanced expression of ORMDL3 compared to the patients with lower disease activity and the non-UC controls" .

• Cytokine correlation analysis: Parallel assessment of cytokine levels is important as "patients showing high ORMDL3 mRNA expression have elevated interleukin-1β cytokine levels indicating positive correlation" .

• In vitro validation: Findings from patient samples should be validated using in vitro models with knockdown and overexpression systems .

• In vivo model confirmation: Animal models (such as dextran sodium sulfate-induced colitis) should be used to confirm mechanisms, as "knockdown of ORMDL3 in a dextran sodium sulfate-induced colitis mouse model showed reduced colitis severity" .

• Multiple cell type assessment: Validation across relevant cell types (such as macrophages for inflammatory conditions) strengthens findings .

How should ORMDL3 antibodies be optimized for tumor immunology studies?

When applying ORMDL3 antibodies in cancer research, optimization strategies include:

Recommended experimental design follows this pattern: "1.5×10^6 LLC cells were subcutaneously implanted into the flanks of C57BL/6 mice. 5×10^5 MC38 cells were implanted the same as LLC cells; after the tumor was established, the volume of tumor was measured once every 2 days" , with parallel assessment of ORMDL3 and immune markers.

How can ORMDL3 antibodies be used to investigate type I interferon signaling pathways?

Recent discoveries highlight ORMDL3's negative regulation of type I interferon signaling, with antibody applications including:

• RIG-I interaction studies: ORMDL3 antibodies can detect changes in RIG-I protein levels, as "ORMDL3 regulates the protein abundance of RIG-I" .

• Pathway component analysis: Immunoblotting for pathway components like IRF3 phosphorylation reveals that "ORMDL3 significantly inhibited poly(I:C) and VSV stimulated transcription of IFNB1" and "Western blots demonstrated a marked reduction in the phosphorylation level of IRF3 when ORMDL3 was overexpressed" .

• Virus-specific effects: Since "ORMDL3 only facilitates RNA virus replication but not DNA virus" , antibody-based detection can help distinguish pathway-specific effects in viral infection models.

• Protein stability investigations: Co-IP studies with ORMDL3 antibodies have revealed potential regulation mechanisms involving deubiquitination proteins .

These approaches have yielded important findings: "ORMDL3 knockdown strikingly suppressed the replication of VSV, whereas overexpression of ORMDL3 enhanced the replication of VSV" , demonstrating the value of antibody-based detection in antiviral response studies.

What are the latest methodological advances in studying ORMDL3 in complex with other proteins?

Advanced techniques for investigating ORMDL3 protein complexes include:

• Mass spectrometry with antibody-based purification: This approach identifies novel interaction partners from cells transfected with flag-vector or flag-ORMDL3 .

• Proximity-dependent labeling: Emerging techniques like BioID or APEX2 can be combined with ORMDL3 antibodies to identify transient or weak interactors in living cells.

• Microscale thermophoresis: This technique can quantify binding affinities between ORMDL3 and potential partners identified in IP-MS studies.

• Structural biology approaches: Cryo-EM studies of ORMDL3 complexes, supported by antibody-based purification, can provide structural insights into functioning.

The established protocol for co-IP-MS includes: "1×10^7 HEK293T cells transfected with flag-vector or flag-ORMDL3 were prepared by washing with cold PBS and then lysed with 1× lysis buffer (Cell Signaling Technology) and incubated on ice for 30 min. Supernatants were collected and immunoprecipitated with the indicated antibodies for 4 hr at 4°C, recovered by adding protein A/G Sepharose Beads overnight" .

How can ORMDL3 expression and function be studied in patient-derived samples?

Investigating ORMDL3 in clinical samples requires specialized approaches:

• Patient stratification: Categorize samples based on disease activity, as demonstrated in UC studies where expression varies with disease severity .

• Combined protein-transcript analysis: Due to antibody cross-reactivity, pair protein detection with qRT-PCR for comprehensive analysis .

• Correlation with clinical parameters: ORMDL3 levels should be analyzed in relation to:

  • Disease severity indices

  • Treatment response metrics

  • Inflammatory marker levels

  • Genetic variant analysis

• Ex vivo functional assays: Patient-derived cells can be used to validate ORMDL3 function in:

  • Cytokine production assays

  • ER-mitochondria contact studies

  • Inflammasome activation assays

Research has shown important clinical correlations: "a subpopulation of the UC patients who had higher disease activity shows enhanced expression of ORMDL3 compared to the patients with lower disease activity and the non-UC controls. We also found that the patients showing high ORMDL3 mRNA expression have elevated interleukin-1β cytokine levels indicating positive correlation" .

How do different experimental systems affect ORMDL3 antibody selection and performance?

The choice and performance of ORMDL3 antibodies vary across experimental systems:

Different systems require specific approaches, as seen in research using "human monocyte-derived macrophages" versus "mouse bone marrow-derived primary macrophages (BMDM)" , each requiring specific protocol optimizations.

What methodological differences exist in detecting ORMDL3 across various inflammatory conditions?

ORMDL3 detection approaches vary across inflammatory conditions:

• Asthma models: Focus on eosinophil-related pathways and sphingolipid metabolism using flow cytometry with ORMDL3 antibodies .

• Inflammatory bowel disease: Emphasis on macrophage NLRP3 inflammasome activation and IL-1β production, requiring detection of ORMDL3 localization to ER-mitochondria contacts .

• Antiviral responses: Analysis of RIG-I pathway components and type I interferon signaling, with measurement of viral replication as functional readout .

• Tumor immunity: Combined assessment of ORMDL3 with T cell markers and IFN-stimulated genes, using flow cytometry and IHC approaches .

These condition-specific approaches reflect ORMDL3's diverse roles in different inflammatory contexts, requiring targeted methodological strategies for optimal detection and functional correlation.