Anti-Human CD307e (FcRL5) [Clone 509F6] — Purified in vivo GOLD™ Functional Grade

Based on the provided search results, there is limited specific information about how clone 509F6 is used in in vivo mouse studies. The search results primarily focus on the antibody's characteristics and in vitro applications rather than detailed in vivo protocols.

Available Information on Clone 509F6

Clone 509F6 is a mouse monoclonal antibody that specifically recognizes human FcRL5 (CD307e), a type I transmembrane glycoprotein. The antibody binds to an epitope within the first 3 immunoglobulin domains of FCRL5 and has the functional capacity to block FCRL5's interaction with immune complexes.

In Vivo Relevance

While the search results don't provide explicit protocols for in vivo mouse studies using clone 509F6, there are important considerations for its potential use:

Functional Grade Designation: One search result specifically mentions this antibody as "Functional Grade In Vivo Gold," suggesting it has been formulated and tested for in vivo applications. This designation typically indicates that the antibody has low endotoxin levels (less than 1.0 EU per dose) and appropriate purity standards for animal studies.

Formulation Considerations: The antibody is available in formulations suitable for in vivo use, being "BSA and azide free" in some preparations, which is important for reducing potential immune reactions in live animals.

Potential Applications

Given that FcRL5 is expressed on naive mature B cells and bone marrow plasma cells, clone 509F6 could potentially be used in mouse studies involving:

• Xenograft models where human cells expressing FcRL5 are transplanted into immunocompromised mice
• Studies of B cell biology and plasma cell function
• Blocking studies to investigate FcRL5's role in immune complex interactions

However, it's important to note that since this is an antibody specific for human FcRL5, it would not be suitable for studying endogenous mouse FcRL5 in wild-type mice, as the antibody shows human species reactivity.

The information available is not sufficient to provide detailed protocols for specific in vivo applications of clone 509F6 in mouse studies. Researchers would need to consult additional literature or contact the manufacturers directly for specific in vivo usage protocols.

Storage Conditions for Sterile Packaged Clone 509F6

For the sterile packaged clone 509F6 antibody, the correct storage temperature is 2–8°C. This temperature range is consistent across several product listings for anti-human CD307e (FcRL5) clone 509F6, specifically indicating that the antibody should be stored undiluted in this range and protected from prolonged exposure to light.

Do not freeze the antibody, as freezing is explicitly cautioned against by multiple suppliers.

For short-term use, the antibody remains stable for at least one week under these sterile conditions. For long-term storage, it is recommended to aseptically aliquot the antibody into working volumes without dilution. However, there is no evidence in the provided sources that freezing is recommended or safe for this clone.

Summary Table

Always consult the specific manufacturer’s documentation for lot-specific details, but the general guidance for clone 509F6 is clear: store at 2–8°C, do not freeze, and protect from light.

Based on the available information, the 509F6 monoclonal antibody (anti-human CD307e/FcRL5) is commonly used alongside several other antibodies and proteins in research applications, particularly in flow cytometry and B cell studies.

Flow Cytometry Panel Components

In flow cytometry applications, 509F6 is frequently used with standard B cell markers to characterize different B cell populations. The antibody is commonly paired with CD19 (an APC-conjugated antibody) and CD27 (FITC-conjugated antibody) to identify and sort B cell subsets. These combinations allow researchers to distinguish between naive B cells, memory B cells, and plasma cells based on their differential expression patterns.

Secondary Detection Antibodies

For detection purposes, 509F6 (which is a mouse IgG2a antibody) is often used with FITC- or PE-conjugated antibodies to mouse IgG2a as secondary reagents. Additionally, when used in multiplex panels, researchers may employ mouse IgG2b secondary antibodies when combining 509F6 with other primary antibodies of different isotypes.

Related Fc Receptor Family Members

The 509F6 antibody is commonly studied alongside antibodies against other members of the FcRL family, particularly anti-FcRL4 (clone 413D12). These antibodies are used together to compare the expression and function of different FcRL proteins, with studies confirming that 509F6 and 413D12 do not cross-react with each other's targets.

Immunoglobulin Binding Partners

Since FcRL5 functions as an Fc receptor, 509F6 is frequently used in studies involving aggregated IgG isotypes of various types. The antibody has blocking capabilities and can prevent FcRL5's interaction with all aggregated IgG isotypes, making it valuable for functional studies examining immune complex interactions.

Technical Support Reagents

In practical applications, 509F6 is commonly used with FcR blocking reagents to prevent non-specific binding during flow cytometry experiments. The antibody is also frequently employed alongside appropriate isotype-matched control antibodies to ensure experimental specificity.

The versatility of 509F6 in these various combinations makes it a valuable tool for studying B cell biology, plasma cell differentiation, and immune complex regulation in both normal and pathological conditions.

Clone 509F6 is a widely used monoclonal antibody that specifically recognizes human FcRL5 (CD307e), and scientific literature reveals several key findings about this antibody's properties and applications.

Specificity and Binding Properties

Clone 509F6 demonstrates highly specific binding to FcRL5 within the first three immunoglobulin domains of the protein. Importantly, this antibody shows no cross-reactivity with the closely related FcRL4 protein, ensuring specificity in research applications. A critical functional finding is that mAb 509F6 can effectively block the binding of FcRL5 to all aggregated IgG isotypes, making it valuable for functional studies investigating FcRL5-IgG interactions.

Target Protein Characteristics

The scientific literature reveals that FcRL5, the target of clone 509F6, is a 106 kDa type I transmembrane glycoprotein with a complex structure containing nine immunoglobulin-like extracellular domains. The protein features both activating and inhibitory signaling motifs, including one cytoplasmic ITAM-like consensus sequence and two cytoplasmic ITIM-like sequences.

Expression Patterns and Distribution

Research using clone 509F6 has established that FcRL5 is predominantly found on mature B cells, with the highest expression levels observed on naive and memory B cells as well as plasma cells. This distribution pattern has been confirmed through flow cytometric analyses using the 509F6 antibody on tonsillar B cells and transfected cell lines.

Functional Insights

Studies utilizing clone 509F6 have revealed that FcRL5 functions as an IgG receptor capable of binding all IgG isotypes. Upon IgG binding, FcRL5 inhibits B cell receptor (BCR) signaling through recruitment of SH2 domain-containing tyrosine phosphatase 1 (SHP-1) following tyrosine phosphorylation of its ITIM domains.

Clinical and Therapeutic Relevance

Research findings using clone 509F6 have identified FcRL5 as a significant biomarker in B cell malignancies. The antibody has been instrumental in demonstrating aberrant FCRL5 expression in multiple myeloma, chronic lymphocytic leukemia, mantle cell lymphoma, and hairy cell leukemia. These discoveries have positioned FcRL5 as both a potential biomarker and therapeutic target.

Most notably, recent therapeutic applications have leveraged the specificity of clone 509F6 in developing FcRH5-targeted CAR-T cell therapies. Research has shown that FcRH5 CAR-T cells demonstrate potent anti-multiple myeloma efficiency in xenograft models, with treated mice showing prolonged survival and sustained presence of human CD3+ T cells weeks after infusion. Furthermore, combination approaches using FcRH5/BCMA CAR-T cells have shown superior efficacy compared to mono-specific treatments, with improved tumor infiltration and longer median survival times.

The clone 509F6 antibody has thus been pivotal in advancing both our understanding of FcRL5 biology and the development of novel immunotherapeutic approaches for B cell malignancies.