SPEAR4 Antibody
Description
SPEAR Antibody Stabilization Technology
The term "SPEAR" (Stabilized Proximity-Enhanced Antibodies) refers to a chemical crosslinking method to enhance antibody stability against thermal and chemical denaturation. This technology enables deep immunostaining applications (e.g., ThICK staining) for large tissue samples like whole mouse brains .
Key Features:
Mechanism:
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Fab Fragment Binding: Primary antibodies are complexed with Fab fragments to form stable IgG-Fab complexes.
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Crosslinking: P3PE (polymerized tris-phenol) crosslinker solubilizes and stabilizes the complex via room-temperature reactions .
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Thermal Acceleration: Enables rapid tissue penetration via heat-assisted diffusion (e.g., 72-hour whole-brain staining) .
SPEAR Protein Detection (DNA Nanotechnology)
A distinct SPEAR (Successive Proximity Extension Amplification Reaction) platform detects ultralow concentrations of proteins (e.g., SARS-CoV-2-neutralizing antibodies) in microliter-scale samples.
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Proximity Probes: Bind to distinct epitopes on target proteins.
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DNA Synthesis: Proximal probes trigger successive DNA extension, generating quantifiable amplicons .
SPEAR T-Cell Therapies
ADP-A2M4CD8 SPEAR T cells are engineered to target MAGE-A4-expressing cancers (e.g., esophageal tumors). While not antibodies, these cells utilize SPEAR (Specific Peptide Enhanced Affinity Receptor) technology.
Clinical Trial (SURPASS-2):
| Parameter | Details | Source |
|---|---|---|
| Phase | 2 (ongoing) | |
| Target Antigen | MAGE-A4 | |
| Patient Eligibility | HLA-A*02+; advanced EGJ/esophageal | |
| Response (Phase 1) | 1 PR, 4 SD, 1 PD in evaluable cases |
SPEAR Bioinformatics Tool
A separate SPEAR platform annotates protein variants in viral genomes (e.g., SARS-CoV-2 Spike mutations) to predict immune escape potential.
Functionality:
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Variant Expansion: Converts compound mutations (e.g., p.G142_Y145delinsD) into individual AA changes .
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Immune Escape Scoring: Ranks mutations by epitope class (Barnes et al.) and structural impact .
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Surveillance Utility: Highlights emerging threats (e.g., Omicron BA sublineages) .
Critical Analysis: Terminology Confusions
The absence of "SPEAR4 Antibody" in literature suggests potential misinterpretation:
| Hypothesis | Rationale |
|---|---|
| Typographical Error | Confusion with "SPEAR" + numeric suffix (e.g., SPEAR-4 as a variant). |
| Proprietary Nomenclature | Unpublished internal naming (e.g., SPEAR4 as a stabilized antibody lot). |
| Overlapping Acronyms | SPEAR refers to distinct technologies (antibody stabilization, protein detection, T-cell therapy). |
Recommendations for Further Inquiry
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Clarify Nomenclature: Confirm if "SPEAR4" refers to a specific stabilized antibody batch (e.g., SPEAR-P3PE), a T-cell product, or a protein detection variant.
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Explore Related Technologies:
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Review Proprietary Databases: Investigate internal or unpublished studies where "SPEAR4" may be used.
Product Specs
Constituents: 50% Glycerol, 0.01M Phosphate Buffered Saline (PBS), pH 7.4
