Anti-Human CD19 [Clone 4G7] – Purified in vivo GOLD^TM Functional Grade

Clone 4G7 refers to two distinct monoclonal antibodies used in mouse studies, most commonly:

• Anti-human CD19 clone 4G7 (used in B cell and CAR-T research)
• Anti-EBOV GP clone 4G7 (used in ebolavirus research)

Based on your query, the most common context in in vivo mouse studies is the anti-human CD19 clone 4G7.

How clone 4G7 is used in in vivo mouse studies:

• Functional Depletion and Targeting of B Cells:
  Clone 4G7 is a mouse anti-human CD19 monoclonal antibody that binds specifically to CD19, a marker on normal and malignant human B lymphocytes. In xenograft or humanized mouse models, it can be administered to selectively deplete human B cells, analyze B cell populations, or serve as a targeting reagent in preclinical immunotherapy studies.

• Development and Testing of CAR-T Therapies:
  The scFv (single-chain variable fragment) of 4G7 is widely used in engineering anti-CD19 CAR-T cells (e.g., UCART19, ALLO-501, and ALLO-501A). These CAR-T cells can be administered to mice with human B cell leukemia/lymphoma xenografts to assess efficacy, pharmacokinetics, and off-target effects.

• Detection and Characterization:
  Antibodies or anti-idiotype reagents that recognize the 4G7 scFv are utilized to detect CAR expression in vivo, often by flow cytometry or immunohistochemistry, to track CAR-T cells or monitor transgene expression in mouse tissues.

• Epitope Mapping and B cell Biology:
  4G7 has been used to investigate CD19 structure-function, variant binding, and has contributed to fine mapping of the CD19 extracellular domain important for immunotherapy design.

Example Use Cases in Mouse Experiments:

• Administering 4G7 directly (as an antibody) into humanized/SCID mice engrafted with human B cells or B cell malignancies to deplete or label these cells.
• Transducing mouse/human T cells with a CAR containing the 4G7 scFv and evaluating efficacy after adoptive transfer into mouse models.
• Tracking persistence, localization, and functional effects of 4G7-derived CAR-T cells using anti-idiotype antibodies against 4G7 in tissue and blood samples.

Care must be taken:

• For studies targeting human cells in mice, NSG or other immunodeficient strains are generally used to avoid immune rejection.
• 4G7 is functional in vivo and suited for preclinical (not clinical) studies.

If you're referring to the anti-EBOV GP (Ebola virus glycoprotein) clone 4G7:

• This antibody is used to study antiviral efficacy, therapeutic delivery, or expression of protective antibodies against Ebola virus in mouse challenge models. For such studies, 4G7-derived antibody genes can be delivered via DNA or viral vectors; in vivo expression and protective efficacy are then examined in mice.

Summary Table: Clone 4G7 Uses in Mouse Studies

If you need procedure details or references for a specific use (e.g., dosage, administration routes, or animal model type), please specify the exact application and target antigen (CD19 vs. EBOV GP).

The correct storage temperature for sterile packaged clone 4G7 antibody depends on the specific product and formulation, but the most cited recommendation for the majority of clone 4G7 antibodies (such as anti-CD19, mouse monoclonal) is to store at 2–8°C (refrigerator temperature) and protect from prolonged exposure to light.

For some recombinant proteins or certain antibody formulations (such as lyophilized or concentrated stocks), the storage recommendation may be -20°C or lower. However, for most routine, ready-to-use antibody solutions of clone 4G7 (including the widely used anti-human CD19 antibodies), the packaging usually specifies:

• Storage: 2–8°C
• Do not freeze
• Protect from light (if conjugated with a fluorochrome)

If your product is specifically labeled as "sterile packaged clone 4G7," and unless it is a unique recombinant protein or a lyophilized vial specifically instructing a different temperature, 2–8°C is the standard.

Check your product label or datasheet for confirmation. If in doubt, contact the manufacturer to verify the best storage conditions for your specific lot.

The 4G7 monoclonal antibody against human CD19 is often used in conjunction with other antibodies or proteins in research and therapeutic applications. Here are some of the commonly used antibodies or proteins that are utilized alongside 4G7:

1. Anti-Id Antibodies: In some studies, antibodies against the idiotype of the 4G7-derived CARs are used. These include antibodies like A8 and E1, which are raised against the 4G7 single-chain variable fragment (scFv) and are used in blocking experiments or flow cytometry analyses to detect CAR T cells.

2. Bispecific Antibodies: Bispecific antibodies combining the specificity of 4G7 (or its scFv) with another antigen-targeting moiety are explored for enhanced therapeutic effects. These bispecific constructs aim to improve targeting and effector function in cancer therapies.

3. CD19-Fc Fusion Proteins: These proteins are used to study the interaction between CD19 and chimeric antigen receptors (CARs) derived from 4G7. They serve as soluble forms of CD19, helping in the analysis of CAR binding specificity and affinity.

4. Chimeric Antigen Receptors (CARs): The 4G7 scFv fragment is frequently used in CAR T cell therapies, where it serves as the targeting component for CD19-positive B cells. These CARs are exploited for treating B cell malignancies.

These combinations highlight the versatility of the 4G7 antibody in immunotherapy research and development.

Key Scientific Findings Related to Clone 4G7

4G7 Identified as a Highly Specific Anti-CD19 Monoclonal Antibody

• Origin and Applications: Clone 4G7 was developed by immunizing mice with chronic lymphocytic leukemia (CLL) cells and specifically recognizes both normal and malignant B lymphocytes, making it valuable for immunophenotyping and diagnostic applications.
• Epitope Mapping: The 4G7 antibody recognizes a conformationally sensitive epitope on the extracellular domain of CD19, centered around amino acid residue R144, with critical binding determinants located between residues 138 and 153. This epitope requires a properly folded extracellular domain for antibody recognition and is not accessible on wild-type CD19 expressed in yeast, but is available on a structurally altered variant (CD19.1).
• Clinical and Research Relevance: 4G7 is among the three most commonly used anti-CD19 antibody clones (alongside FMC63 and 4G7-2E3) in preclinical detection of CD19, reflecting its prominence in B-cell research and diagnostics.

4G7-Derived ScFvs in CAR-T Cell Therapies

• CAR-T Engineering: The single-chain variable fragment (scFv) from 4G7 is used in the construction of chimeric antigen receptors (CARs) targeting CD19, such as UCART19 and ALLO-501. These CAR-T cells are engineered for therapeutic use against B-cell malignancies.
• Detection and Characterization Tools: High-affinity anti-idiotype antibodies (e.g., clone A8, E11) have been developed to specifically detect and quantify 4G7-derived CARs on transduced cells, enabling precise monitoring of CAR expression and function in research and therapy (including flow cytometry-based assays).
• Binding Affinity: The antigen-binding domain of 4G7-based CARs binds with high to very high affinity, with dissociation constants (Kd) typically around 1 nM (range: 0.1–5 nM). Some engineered domains achieve Kd values as tight as 10??–10?¹² M, reflecting robust target engagement in therapeutic contexts.
• Functional Blockade: Anti-idiotype antibodies targeting the 4G7 scFv can block CAR binding and function, as demonstrated by experiments showing inhibition of tumor cell lysis by UCART19 at various effector-to-target ratios.

Summary Table: Key Features and Uses of Clone 4G7

Implications

• Diagnostic Utility: 4G7 is widely employed for identifying B-cell malignancies due to its specificity for CD19 on B lymphocytes.
• Therapeutic Innovation: The 4G7-derived scFv is a cornerstone of several CD19-targeted CAR-T therapies, with engineered detection systems enabling precise tracking and functional interrogation of these therapies in clinical settings.
• Research Tools: Development of high-affinity, anti-4G7 reagents allows for both the quantification and functional modulation of 4G7-based CAR-T cells, supporting both preclinical and clinical development phases.

Clone 4G7 is thus foundational in both the molecular understanding of CD19 and the development of next-generation immunotherapies for B-cell diseases.