TNFR Human, His
Description
Production and Purification
Physicochemical Properties
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Formulation:
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Stability:
Functional Applications
TNFR Human, His is utilized in:
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Ligand-Binding Assays: Binds TNF-α with a linear range of 3–25 ng/mL in ELISA .
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Signaling Studies: Investigates TNFR1-mediated pathways, including NF-κB activation, apoptosis, and inflammation .
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Therapeutic Development: Serves as a reference standard for anti-TNF-α drug screening .
Research Findings
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TNFR1 vs. TNFR2 Signaling: TNFR1 (ubiquitously expressed) drives pro-inflammatory and apoptotic responses, while TNFR2 (immune-cell-restricted) promotes tissue repair .
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Cardiac Function: TNFR1 activation in cardiac myocytes directly induces negative inotropic effects, implicating it in heart failure pathogenesis .
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Autoimmunity: Selective TNFR1 inhibition reduces inflammation without compromising TNFR2-mediated immune regulation .
Key Data Table: TNFR Human, His Variants
Product Specs
DTDCRECESGSFTASENHLRHCLSCSKCRKEMGQVE
ISSCTVDRDTVCGCRKNQYRHYWSENLFQCFNCSLCL
NGTVHLSCQEKQNTVCTCHAGFFLRENECVSCSNCKK
SLECTKLCLPQIEN.
Q&A
What structural features of TNFR1 influence its ligand-binding specificity and downstream signaling?
TNFR1 contains four cysteine-rich domains (CRDs) in its extracellular region, which mediate binding to TNF-α and lymphotoxin-α . The intracellular death domain (DD) facilitates interactions with adaptor proteins like TRADD and FADD, initiating pro-apoptotic or NF-κB signaling pathways . Researchers should prioritize structural mutagenesis experiments to map CRD residues critical for ligand binding. For example, ELISA-based binding assays using recombinant TNFR1 mutants (e.g., substituting cysteine residues in CRD3) can quantify affinity changes for TNF-α . Surface plasmon resonance (SPR) further resolves kinetic parameters (e.g., k<sub>on</sub>, k<sub>off</sub>) to distinguish high- versus low-affinity interactions.
How do researchers quantify soluble TNFR1 (sTNFR1) in human serum, and what are the technical limitations?
sTNFR1 is commonly measured via ELISA, leveraging antibody pairs specific to the receptor’s extracellular domain. A validated protocol involves:
What baseline variables correlate with TNFR1 levels in population studies?
In the Northern Manhattan Study (n = 1,863), TNFR1 levels averaged 2.57 mg/L (SD = 1.72) and associated with demographic and clinical factors :
| Variable | Association with TNFR1 Levels | P Value |
|---|---|---|
| Age (per 10-year increase) | +0.8 mg/L | <0.001 |
| Female sex | +0.3 mg/L | 0.02 |
| Hypertension | +1.1 mg/L | <0.001 |
| Diabetes mellitus | +1.4 mg/L | <0.001 |
Adjusting for these confounders is critical when analyzing TNFR1 as a biomarker. For instance, multivariable regression models should include age, sex, and metabolic comorbidities to isolate TNFR1’s independent effects .
How can longitudinal studies disentangle TNFR1’s role in functional decline from concurrent vascular events?
The Northern Manhattan Study employed generalized estimating equations (GEE) to model TNFR1’s association with Barthel Index (BI) trajectories over 13 years . Key steps include:
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Time-varying adjustment: Incorporate stroke and myocardial infarction (MI) as time-dependent covariates in GEE models.
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Interaction terms: Test whether TNFR1’s effect on BI decline (β = −0.36 points/year per SD increase ) is modified by incident vascular events.
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Sensitivity analyses: Compare GEE results with mixed-effects models to assess robustness against correlation structure assumptions.
This approach revealed that TNFR1 predicted accelerated functional decline (β = −0.36, 95% CI: −0.69, −0.03) independent of stroke/MI occurrence .
What experimental strategies resolve contradictions in TNFR1’s dual pro-inflammatory and anti-inflammatory roles?
TNFR1 signaling exhibits context-dependent outcomes: membrane-bound TNF-α triggers inflammation via NF-κB, while soluble TNF-α may promote apoptosis . To address this paradox:
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Cell-type-specific knockdown: Use siRNA to silence TNFR1 in macrophages versus endothelial cells and quantify cytokine profiles (e.g., IL-6, IL-10).
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Ligand-specific stimulation: Compare responses to transmembrane TNF-α (non-cleavable mutants) versus recombinant soluble TNF-α.
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Proteomic profiling: Identify phosphorylation patterns in the TNFR1 signaling complex under different ligand conditions (e.g., TRAF2 recruitment versus caspase-8 activation).
How do TNFRSF1A mutations alter TNFR1 function in autoinflammatory diseases?
Over 80 TNFRSF1A mutations are linked to TNF receptor-associated periodic syndrome (TRAPS). Functional assays include:
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Surface expression analysis: Transfect HEK293 cells with mutant TNFR1 constructs and measure membrane localization via flow cytometry.
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NF-κB luciferase reporters: Quantify pathway activation upon TNF-α stimulation (e.g., Cys73Phe mutants show constitutive activation ).
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Shedding assays: Assess ectodomain cleavage efficiency using metalloprotease inhibitors (e.g., TAPI-1) to differentiate shedding-deficient mutants.
What statistical approaches optimize power for detecting TNFR1-disease associations in heterogeneous cohorts?
In the Northern Manhattan Study, GEE models accounted for repeated BI measures and baseline covariates :
| Model Component | Specification |
|---|---|
| Correlation structure | Exchangeable |
| Link function | Identity |
| Adjustment variables | Age, sex, vascular risk factors, social determinants |
For smaller cohorts, penalized regression (e.g., LASSO) can prioritize covariates without overfitting. Pre-specified interaction terms (e.g., TNFR1 × time) are essential for evaluating longitudinal effects.
How do researchers validate TNFR1 interactors identified via high-throughput screens?
After initial discovery (e.g., GRN-TNFR1 binding ), orthogonal assays are required:
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Co-immunoprecipitation (Co-IP): Confirm physical interaction in endogenous protein contexts.
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Microscale thermophoresis (MST): Measure binding affinity (K<sub>d</sub>) between recombinant TNFR1 and GRN.
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Functional rescue: Knock down GRN in TNFR1-overexpressing cells and assay apoptosis (e.g., caspase-3/7 activation).
Why do some studies report TNFR1 as neuroprotective, while others implicate it in neurodegeneration?
This discrepancy arises from model systems and ligand availability:
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In vitro studies: Neuronal cultures exposed to soluble TNF-α show TNFR1-mediated neurotoxicity via caspase-8 .
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In vivo models: Transgenic mice with neuron-specific TNFR1 overexpression exhibit reduced amyloid-β plaques due to enhanced microglial phagocytosis .
Resolution requires in situ hybridization to map TNFR1 expression across brain cell types and single-cell RNA sequencing to delineate context-specific signaling networks.
Product Science Overview
Tumor Necrosis Factor Receptors (TNFRs) are a group of receptors that bind to Tumor Necrosis Factors (TNFs), which are cytokines involved in systemic inflammation and are part of the body’s immune response. The TNFR family plays a crucial role in regulating immune cells, apoptosis, and inflammation.
The Tumor Necrosis Factor Receptor Type (Human Recombinant, His Tag) is a recombinant protein produced in E. coli. It is a single, non-glycosylated polypeptide chain containing 161 amino acids, with a molecular weight of approximately 22.68 kDa. This protein is fused with a 4.5 kDa amino-terminal hexahistidine tag (His Tag) to facilitate purification and detection .
The TNFRs are characterized by their ability to bind TNFs via an extracellular cysteine-rich domain. This interaction is crucial for the receptor’s role in mediating the effects of TNFs, which include cell proliferation, differentiation, and apoptosis .
There are two main types of TNFRs:
The recombinant form of TNFR with a His Tag is widely used in research and therapeutic applications. The His Tag allows for easy purification and detection using nickel affinity chromatography and anti-His antibodies, respectively. This makes it a valuable tool for studying the receptor’s function and for developing therapeutic agents targeting TNFRs.
TNFRs, particularly TNFR2, have been identified as potential therapeutic targets for various diseases, including cancer and autoimmune disorders. TNFR2 promotes tumor immune escape by stimulating immune suppressive cell types, such as regulatory T-cells (Tregs) and myeloid-derived suppressor cells (MDSCs). This makes it a promising target for cancer immunotherapy .
