IFNLR1 Monoclonal Antibody
Description
Definition and Biological Context
IFNLR1 is the ligand-binding subunit of the heterodimeric receptor for IFN-λs, cytokines that mediate antiviral and immunomodulatory responses . Unlike ubiquitously expressed type I interferon receptors, IFNLR1 is restricted to epithelial cells and select immune cells (e.g., plasmacytoid dendritic cells [pDCs], B cells) . Monoclonal antibodies against IFNLR1 are engineered to either detect its cell surface expression or block its interaction with IFN-λs, thereby modulating downstream signaling .
Development and Characterization
Several IFNLR1 mAbs have been developed and validated for specificity and functionality:
Table 1: Key IFNLR1 Monoclonal Antibodies
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HLR14: Distinguished by its ability to reliably detect IFNLR1 on primary human B cells and pDCs via flow cytometry .
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MMHLR-1: Neutralizes IFN-λ-mediated signaling by binding extracellular domains, validated in lupus and viral infection models .
Applications in Research
IFNLR1 mAbs are pivotal in elucidating IFN-λ biology:
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Immune Cell Profiling: HLR14 confirmed IFNLR1 expression on activated human B cells, pDCs, and monocytes .
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Disease Mechanisms:
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Viral Infections: IFNLR1 mAbs help quantify receptor levels during antiviral responses at mucosal barriers .
Table 2: Species-Specific IFNLR1 Signaling Effects
| Cell Type | Mouse Response to IFN-λs | Human Response to IFN-λs |
|---|---|---|
| Neutrophils | ↑ ISG expression, variable ROS production | ↓ ROS production, ↓ NET formation |
| B cells | No response | ↑ TLR7-mediated antibody production |
| Dendritic cells | ↑ T cell polarization, antigen presentation | ↑ Cytokine production, antigen presentation |
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Species Discrepancies: Mouse B cells lack IFNLR1 responsiveness, unlike human B cells .
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Therapeutic Insights: IFNLR1 mAbs highlight IFN-λ's dual role in inflammation (pro-inflammatory in SLE; anti-inflammatory in RA) .
Future Directions
Current challenges include reconciling discrepancies in IFNLR1 expression across species and tissues . Advances in mAb specificity (e.g., HLR14) will refine therapeutic targeting of IFN-λ pathways in autoimmune and viral diseases .
Product Specs
This IFNLR1 monoclonal antibody was generated by immunizing mice with recombinant IFNLR1 protein (amino acids 21-228). Splenic B cells were isolated and fused with myeloma cells to create hybridomas. Hybridomas producing the IFNLR1 monoclonal antibody were selected and cultured in the mouse abdominal cavity. The antibody was purified from the resulting ascites using protein A affinity chromatography, achieving >95% purity. This highly specific antibody targets human IFNLR1 and is suitable for ELISA and immunofluorescence (IF) applications.
IFNLR1 plays a crucial role in mediating antiviral responses to viral infections. Upon activation by interferon-lambda (IFN-λ), IFNLR1 forms a heterodimer with IL10RB, triggering the JAK-STAT signaling pathway. This leads to the upregulation of interferon-stimulated genes (ISGs), which are critical components of innate immunity and antiviral defense. Furthermore, IFNLR1 signaling is implicated in various inflammatory diseases, including psoriasis and inflammatory bowel disease.
Target Background
The IFNLR1/IL10RB heterodimer serves as a receptor for the cytokine ligands IFNL2 and IFNL3, mediating their antiviral effects. Ligand binding activates the JAK/STAT signaling pathway, resulting in the expression of interferon-stimulated genes (ISGs) and the establishment of an antiviral state. This receptor complex dictates the cell type specificity of lambda interferon action, exhibiting a restricted expression pattern primarily in epithelial tissues of the respiratory, gastrointestinal, and reproductive tracts. While not essential for early host defense against vaginal infections, IFNLR1 plays a significant role in Toll-like receptor (TLR)-induced antiviral defense and contributes substantially to antiviral immunity in the intestinal epithelium.
- IFN-lambda4 suppressed HIV infection in macrophages; this inhibition was significantly reduced by antibodies targeting the IFN-lambda receptor complex (IFNLR1/IL-10R2). PMID: 30247785
- Four variants in IFNAR2 and IFNLR1 showed significant associations with hepatitis B virus infection; specifically, IFNLR1 rs4649203 was linked to hepatitis B recovery. Five polymorphisms in IFNA1, IFNA2, and IFNL4 were also associated with hepatocellular carcinoma. PMID: 29080269
- Structural analysis revealed an 85-Å extended receptor peptide, where both box1 and box2 regions simultaneously bind to the FERM and SH2-like domains of JAK1. PMID: 27725180
- IFNLR1 box1 and box2 motifs are essential for stable complex formation with JAK1. Structural studies identified the IFNLR1 box1 binding site within the FERM domain of JAK1 and a critical PxxLxF motif. Structural comparisons revealed conservation among class II receptors. PMID: 27133025
- Selective IFN-lambdaR1 expression enhances the targeted antiviral activity of IFN-lambdas; controlled expression could further improve therapeutic efficacy. PMID: 27166550
- IL-28RA mRNA expression may correlate with systemic lupus erythematosus pathogenesis. PMID: 25911176
- Polymorphisms in IL-28R1, but not IL-28B, are associated with benign prostatic hyperplasia and lower urinary tract symptoms in a Chinese population. PMID: 26400298
- No significant differences were observed in the distribution of IL10RB and IL28RA genotypes between Hepatitis C virus-infected and control groups. PMID: 24144988
- Type III interferon responses were activated in low-risk human papillomavirus-positive cervical cells; the absence of this response may be linked to lesion progression. PMID: 24510368
- The IL28RA polymorphism (rs10903035) may influence glucose homeostasis, with the AA genotype increasing insulin resistance risk; however, this association varies depending on hepatic fibrosis and HCV genotype. PMID: 24438680
- Epigenetic modifications of the IFNLR1-mediated response enhance antiviral activity and suppress tumor growth. PMID: 24409098
- IFN-lambdaR1 expression is induced in chronic hepatitis C, correlating with the IFN-lambda3 genotype and non-responsiveness to IFN-alpha therapies. PMID: 24752298
- The IL28RA rs12980275 AG/GG genotype and rs10903035 G allele were independently associated with early failure of pegylated interferon and ribavirin therapy in hepatitis C/HIV co-infected patients. PMID: 23565619
- Plasmacytoid dendritic cells are major producers of IFN-lambda2 (a type III interferon) and express functional receptors for this cytokine. PMID: 22891284
- No consistent association was found between IL28RA and multiple sclerosis in a Basque-Spanish population. PMID: 22386267
- Two SNPs in IL28RA correlate with susceptibility to HCV infection and spontaneous viral clearance, indicating a crucial role for IL28RA in HCV infection outcomes. PMID: 21742059
- IFN-lambdaR1 comprises two distinct fibronectin type III domains. PMID: 20934432
- Despite minor differences in ligand expression systems, the IFN-lambda1(Bac)-IFN-lambda1R1 and IFN-lambda1(Ins)-IFN-lambda1R1 complexes exhibited significant differences in crystallization conditions and crystal forms. PMID: 20057073
- IFN-lambdas do not affect all cell types; membrane-associated IFN-lambdaR1 expression alone is insufficient for cellular responsiveness to these cytokines. PMID: 19798076
- IL-28 and IL-29 utilize a heterodimeric class II cytokine receptor comprising IL-10 receptor beta (IL-10Rbeta) and the orphan receptor IL-28Ralpha. PMID: 12469119
- All three IFN-lambda proteins utilize a signaling receptor complex consisting of CRF2-12 (IFN-lambdaR1) and CRF2-4 (IL-10R2). PMID: 12483210
- Tyrosine residues within the IL-28 receptor are involved in the antiviral and antiproliferative activities of IL-29/interferon-lambda 1. PMID: 15166220
- The IL-28RA g.32349 G>A polymorphism may be associated with allergic rhinitis susceptibility. PMID: 16819289
Q&A
How do researchers validate the specificity of IFNLR1 monoclonal antibodies for flow cytometry?
Validation requires a multi-step approach combining genetic, biochemical, and functional assays. In a 2023 study, HLR14 mAb specificity was confirmed using IFNLR1-knockout Huh7 cells, where only 2.9% of cells showed background staining compared to 9.5% in wild-type cells . Researchers should:
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Use isogenic controls: Compare staining in wild-type vs. CRISPR-generated IFNLR1 knockout cell lines.
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Ligand blocking: Pre-incubate cells with recombinant IFN-λR1 extracellular domain (ECD) to compete for antibody binding.
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Cross-verification: Compare flow cytometry results with mRNA quantification (e.g., qPCR for IFNLR1) across cell types.
Table 1: Validation Metrics for IFNLR1 mAbs
| Parameter | HLR1 (Non-functional) | HLR14 (Functional) |
|---|---|---|
| ELISA Binding | Strong | Strong |
| Flow Cytometry | Negative | Positive |
| Neutralization | No | Yes |
| Primary Cell Staining | Unreliable | Reliable (pDCs, B cells) |
| Data synthesized from |
What criteria determine the selection of IFNLR1 mAbs for neutralization assays?
Functional mAbs must meet three criteria:
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Epitope accessibility: Antibodies targeting the IFN-λ binding site (e.g., HLR14) block ligand-receptor interaction .
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Species cross-reactivity: Murine-specific mAbs (e.g., 5G12F3) are preferred for in vivo studies .
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Isotype compatibility: IgG2a isotypes enhance antibody-dependent cellular cytotoxicity in therapeutic models .
How do IFNLR1 isoforms influence antibody-based detection and functional studies?
Three isoforms of IFNLR1 exist, with isoforms 2 and 3 lacking full signaling capacity. A 2023 study using FLAG-tagged isoforms revealed:
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Isoform 1 overexpression amplifies antiviral gene expression (e.g., MX1, ISG15) by 4–7-fold compared to controls .
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Isoform 2 partially inhibits IFN-λ signaling at high concentrations (EC50 increases from 12 nM to 48 nM) .
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Isoform 3 shows no detectable surface expression, necessitating intracellular staining protocols .
Table 2: Impact of IFNLR1 Isoforms on Antiviral Responses
| Isoform | Surface Expression | IFNL3-Induced ISG15 | HBV Inhibition |
|---|---|---|---|
| 1 | High | ↑↑↑ | 98% |
| 2 | Low | ↑ | 42% |
| 3 | Undetectable | ↔ | 8% |
| Data from |
What experimental strategies resolve contradictions between mRNA and protein expression data?
Discrepancies arise due to post-transcriptional regulation and isoform-specific antibody reactivity. A 2023 methodology recommends:
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Multi-epitope mapping: Use mAbs targeting distinct domains (e.g., ECD vs. intracellular).
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Proteomic normalization: Spike-in SILAC standards to quantify receptor density per cell .
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Single-cell RNA-seq correlation: Pair flow cytometry with transcriptomic data in primary cells.
How should researchers optimize IFNLR1 mAb dosing for in vivo antiviral studies?
Key parameters from SARS-CoV-2 challenge models include:
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Prophylactic dosing: 10 μg/g body weight administered intranasally 72 hrs pre-infection reduces lung viral load by 3.8-log .
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Therapeutic window: Dosing at 24–48 hrs post-infection still lowers nasal turbinate titers by 2.4-log .
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Tissue-specific clearance: Lung homogenates require 2–3× higher mAb concentrations than nasal washes for complete neutralization .
What controls are essential when using IFNLR1 mAbs in CRISPR-edited models?
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Genotypic validation: Sanger sequencing of PCR-amplified IFNLR1 loci to confirm frameshift mutations .
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Functional rescue: Transient transfection of full-length IFNLR1 in knockout cells to restore antibody staining .
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Off-target checks: RNA-seq to verify unchanged expression of related receptors (e.g., IFNAR2, IL10RB) .
How can researchers address batch-to-batch variability in commercial IFNLR1 mAbs?
While avoiding brand-specific recommendations, academic labs should:
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Standardize lot testing: Compare new batches using a frozen aliquot of reference cells (e.g., HEK293T-IFNLR1).
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Titration grids: Establish EC90 values for each lot via serial dilution in flow cytometry.
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Inter-lab calibration: Share normalized datasets through platforms like Zenodo or BioStudies.
What statistical approaches differentiate specific vs. non-specific staining in low-expressing cells?
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Mixture modeling: Fit flow cytometry data to bimodal distributions using tools like FlowJo’s Probability Binning.
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Background subtraction: Calculate ΔMFI (median fluorescence intensity) between test and IFNLR1−/− controls .
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Signal-to-noise thresholds: Require ≥5:1 ratio between positive populations and isotype controls.
How do researchers validate IFNLR1 mAbs for multiplexed cytokine signaling studies?
A 2023 multiplex assay design incorporated:
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Receptor co-staining: Pair IFNLR1 mAbs with antibodies against phosphorylated STAT1/STAT3.
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Temporal resolution: Sample cells at 15, 30, and 60 mins post-IFN-λ stimulation.
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Inhibitor controls: JAK1/2 inhibitors (e.g., ruxolitinib) to confirm signaling specificity .
What emerging techniques address IFNLR1 mAb limitations in 3D tissue models?
Innovative approaches include:
