Anti-Mouse CD120a (TNFR1) [Clone 55R-170]

Use of Clone 55R-170 in In Vivo Mouse Studies

Clone 55R-170 is a well-characterized monoclonal antibody that specifically targets mouse CD120a, also known as Tumor Necrosis Factor Receptor I (TNFR1 or TNFRSF1A). It is an Armenian hamster IgG1 antibody that has been explicitly developed and purified for in vivo use in mice.

Primary Functions

• Blockade of TNFRI Signaling: 55R-170 binds to mouse TNFR1, blocking its interaction with TNF-? (and the related ligand LT-?, TNF-?), thereby inhibiting downstream signaling via this receptor. This blockade disrupts pathways that mediate apoptosis, NF-?B activation, inflammation, and other TNF-dependent cellular responses.
• Cytokine Storm Protection: In vivo, injection of 55R-170 has been shown to protect mice from lethal endotoxin shock—a classic model of systemic inflammation and cytokine storm. This protective effect is specific to TNFR1 (p55) and is not observed with antibodies targeting TNFR2 (p75).
• Infection Models: 55R-170 also blocks the development of a protective immune response against Listeria monocytogenes infection in mice, further demonstrating its potency in modulating TNF-dependent immune pathways in vivo.

Administration and Formulation

• Low Endotoxin Preparations: For in vivo use, 55R-170 is available in formats specifically purified to minimize endotoxin levels, crucial for reducing off-target inflammatory effects in animal studies.
• Administration: The antibody is typically delivered by intraperitoneal (IP) or intravenous (IV) injection. The exact dose, timing, and regimen depend on the experimental model and should be tailored based on published protocols or pilot studies.
• No Carrier Protein or Preservatives: Commercial preparations are formulated in PBS without BSA or azide, making them suitable for direct in vivo injection.

Key Applications in Research

• Inflammatory Disease Models: Used to dissect the role of TNFR1 in acute and chronic inflammation, sepsis, and autoimmunity.
• Tumor Models: Investigates the impact of TNF signaling blockade on tumor growth, necrosis, and immune regulation.
• Infection Studies: Explores how TNFRI signaling influences host defense against bacterial and viral pathogens.
• Cytokine Storm and Sepsis: Used to protect against TNF-driven pathologies, such as endotoxin shock.

Selectivity and Specificity

• No Cross-Reactivity: 55R-170 does not cross-react with TNFR2 (p75), allowing specific targeting of the TNFR1 pathway.
• Functional Antagonism: The antibody acts as a competitive antagonist, preventing ligand binding and subsequent receptor activation.

Summary Table

Conclusion

Clone 55R-170 is a critical tool in mouse immunology research for selectively blocking TNFR1 signaling in vivo. Its use has elucidated the distinct roles of TNF receptors in inflammation, infection, and cytokine storm, providing mechanistic insights and therapeutic hypotheses relevant to human disease. Researchers should use low-endotoxin, carrier-free preparations and follow established in vivo protocols to maximize experimental validity.

The correct storage temperatures for the sterile packaged Armenian Hamster monoclonal antibody to Mouse CD120a (Clone 55R-170) are as follows:

• For long-term storage, the antibody should be stored at -20°C.
• For short-term storage, it can be stored at 4°C or in a refrigerator at temperatures between 2-8°C for up to one month.

It is important to maintain sterile conditions and avoid freeze-thaw cycles to preserve the antibody's efficacy.

Commonly Used Antibodies and Proteins Paired with 55R-170

55R-170 is a monoclonal antibody that specifically targets the mouse TNF Receptor I (CD120a/p55/TNFRSF1A). It has been widely used in research applications, and in the literature, several other antibodies and proteins are commonly paired with or referenced alongside 55R-170, particularly for multi-step assays or functional characterization.

Commonly Paired Antibodies

Other Commonly Referenced Proteins

• TNF-? and LT-? (TNF-?): The natural ligands for TNFRI/CD120a, often used in functional assays to assess receptor blockade or activation.
• TRADD and RIP: Signaling adaptor proteins associated with TNFRI that mediate downstream signaling events (e.g., apoptosis, NF-?B activation). These are not direct targets of 55R-170, but are often discussed in the context of TNFRI signaling pathways in which 55R-170 is used to block receptor function.
• Biotinylated anti-Armenian hamster IgG and SAv-PE: These are used in multi-step flow cytometry protocols to enhance detection when biotinylated 55R-170 is employed.

Functional and Technical Context

• ELISA: The biotinylated 55R-170 is frequently used as a detection antibody in tandem with a purified capture antibody such as 55R-286 for measuring soluble TNF receptors in serum.
• Flow Cytometry: Biotinylated 55R-170 may be detected using streptavidin conjugates (e.g., SAv-PE) or a secondary anti-Armenian hamster IgG reagent, especially when signal amplification is needed.
• Functional Assays: 55R-170 and 55R-176 are compared for their ability to neutralize TNF bioactivity in vitro and in vivo, often alongside anti-p75 antibodies to dissect the roles of each receptor type.
• Epitope Mapping: Non-competing pairs of p55- and p75-specific hamster mAbs (including 55R-170 and others) are used to develop receptor-specific ELISAs and to study receptor-ligand interactions.

Summary Table: Key Pairings

Conclusion

In the literature, 55R-170 is most commonly used alongside 55R-286 in ELISA formats, 55R-176 and anti-p75 antibodies in functional and comparative studies, and biotinylated detection systems (SAv-PE, anti-Armenian hamster IgG) in flow cytometry. The natural ligands TNF-? and LT-?, as well as downstream signaling adaptors like TRADD and RIP, are also frequently referenced in the context of TNFRI biology when 55R-170 is employed to block or modulate receptor activity.

Key Findings from Clone 55R-170 Citations in Scientific Literature

Clone 55R-170 is a monoclonal antibody that specifically recognizes mouse CD120a, also known as Tumor Necrosis Factor Receptor Type I (TNFR1). While the direct, primary scientific literature specifically reporting novel biological findings using clone 55R-170 is limited in the provided search results, there are several important insights based on its documented specificity, functional applications, and the biology of its target, TNFR1.

Specificity and Functional Use of Clone 55R-170

• Target Specificity: Clone 55R-170 is validated for detecting mouse TNFR1 (CD120a), a 55 kDa type I transmembrane protein. It does not cross-react with TNFR2 (CD120b).
• Functional Blockade: Binding of 55R-170 to TNFR1 has been shown to block receptor signaling both in vitro and in vivo, effectively inhibiting downstream effects initiated by TNF-? and lymphotoxin-? (LT-?, also known as TNF-?).
• Application in Research: The antibody is used in functional-grade preparations, suitable for blocking experiments to dissect the roles of TNFR1 in various biological processes.

Biological Significance of TNFR1 (CD120a)

While most cited literature does not describe novel findings specifically from experiments using clone 55R-170, the broader scientific understanding of TNFR1’s role—which 55R-170 interrogates—includes:

• Signal Transduction: TNFR1 activation leads to NF-?B induction, apoptosis, inflammation, antiviral and cytolytic activities, and upregulation of adhesion molecules such as ICAM-1.
• Adhesion Molecule Regulation: Genetic knockout and receptor blockade studies (which could utilize antibodies like 55R-170) show that TNFR1 signaling is crucial for TNF-induced upregulation of adhesion molecules (E-selectin, VCAM-1, and ICAM-1) on endothelial cells. Mice lacking TNFR1 show significantly reduced expression of these molecules after TNF stimulation.
• Apoptosis Pathway: TNFR1 contains a death domain that transmits apoptotic signals via interaction with TRADD (TNF Receptor I Associated Death Domain protein).

Summary Table: Key Points

Limitations in the Literature

There is limited direct evidence in the provided search results of novel biological discoveries attributed specifically to experiments using clone 55R-170. Most references focus on its validation as a specific TNFR1-blocking tool rather than reporting new mechanistic insights generated by its use. The broader literature on TNFR1, however, underscores its critical role in inflammation, apoptosis, and immune regulation, all of which are pathways that would be disrupted by 55R-170-mediated blockade.

Conclusion

Clone 55R-170 is a well-characterized, functional-grade monoclonal antibody against mouse TNFR1, widely used to block TNFR1 signaling and study its role in inflammation, apoptosis, and immune responses. While direct, novel scientific findings from the use of this clone are not extensively detailed in the provided literature, its application is foundational for elucidating the specific contributions of TNFR1 in diverse biological contexts. For deeper mechanistic insights, additional primary literature specifically employing 55R-170 in experimental models would be required.