Anti-Human HLA A2,B7 (MHC Class I) – Purified in vivo PLATINUM™ Functional Grade

Clone BB7.6 is a mouse monoclonal antibody that specifically recognizes a shared epitope (Bw6) on human MHC class I molecules, especially HLA-A2 and HLA-B7. In in vivo mouse studies, it is used primarily for the identification, depletion, or functional blockade of human HLA-A2/B7-positive cells in mouse models, particularly in humanized mice or xenograft studies where human immune cells or tissues are introduced into mice.

Key uses in in vivo mouse studies:

• Detecting human cells: BB7.6 is commonly used by flow cytometry to detect human HLA-A2/B7-expressing cells in the peripheral blood, tissues, or tumors of engrafted mice.
• Functional assays or depletion: The antibody, especially in low-endotoxin, functional-grade formulations, can be administered to mice to block, modulate, or deplete HLA-A2/B7-positive human cells in vivo, enabling the study of HLA-restricted immune responses or the role of specific cell types.
• Validation of humanization: In humanized mouse models (e.g., NSG or NOG mice reconstituted with human hematopoietic stem cells), BB7.6 helps confirm the engraftment and persistence of human cells bearing these major HLA alleles.

Formulations for in vivo use:

• Functional-grade BB7.6 antibodies are purified to minimize endotoxin and protein aggregates, which is critical for safe in vivo administration.
• The antibody is provided in buffer suitable for injection, and suppliers typically advise on dosage, frequency, and administration route in their product datasheets.

In summary, clone BB7.6 is essential for tracking, quantifying, or functionally interfering with HLA-A2/B7-positive human cells in humanized or xenograft murine models—most often through flow cytometry and functional in vivo assays using specially formulated, low-endotoxin antibody preparations.

Storage Temperature for Clone BB7.6 (Anti-HLA-A2, B7 Antibody)

For clone BB7.6—also referred to as Anti-HLA-A2, B7 monoclonal antibody—the recommended storage conditions are:

• Short-term (up to 4 weeks): Store at 2–8°C (refrigerated).
• Long-term: Aliquot in working volumes (without dilution) and store at –20°C or –80°C.

Additional Best Practices

• Aliquoting: Divide the antibody into small working aliquots to avoid repeated freeze-thaw cycles, which can degrade protein stability and reduce antibody activity.
• Avoid Frost-Free Freezers: Use non-frost-free freezers for –20°C storage, as frost-free units undergo temperature fluctuations that may harm the antibody.
• Location in Freezer/Refrigerator: Store aliquots toward the back of the appliance, away from the door, to minimize temperature fluctuations.

Summary Table

Always check the specific manufacturer’s instructions for any additional recommendations, as stability can vary with formulation and buffer. For clone BB7.6, the above guidelines are consistent with both general monoclonal antibody storage practices and product-specific documentation.

In the literature, BB7.6 is often associated with the recognition of HLA-Bw6 epitopes. However, specific combinations with other antibodies or proteins are not frequently mentioned in the provided search results. Instead, the search results highlight other monoclonal antibodies and proteins, such as PA2.1 and BB7.2, which are used in the context of HLA studies, and B7 family members like B7-H4 and B7-H6, which are involved in immune regulation and tumor targeting.

Here are some commonly used antibodies and proteins in the context of HLA and immune regulation studies:

Commonly Used Antibodies and Proteins

• PA2.1 and BB7.2: These antibodies are used to study HLA-A subtypes, particularly recognizing cross-reactive groups including A2, A23, A24, A68, and A69 antigens.
• W6/32: A monoclonal antibody with broad specificity for HLA class I antigens.
• BB7.1: Recognizes HLA-B07:02, B42:01, and B*81:01, based on their ?1 domain sequences.
• B7 Family Members:
  • B7-H4: Acts as a co-inhibitory molecule, expressed on antigen-presenting cells and cancer cells, and is involved in immune regulation.
  • B7-H6: A ligand for NKp30, found on tumor cells, and is targeted in cancer therapy.

These antibodies and proteins are used in various contexts for studying HLA epitopes, immune regulation, and cancer treatments, but specific combinations with BB7.6 are not detailed in the available information.

Key Findings on Clone BB7.6 from Scientific Literature

Clone BB7.6 is a monoclonal antibody primarily referenced in the context of HLA (human leukocyte antigen) epitope recognition, specifically for the Bw6 public epitope on HLA class I molecules. Below are the main findings from the literature regarding BB7.6:

Epitope Specificity and Binding Requirements

• Bw6 Epitope Recognition: BB7.6 is identified as an anti-Bw6 monoclonal antibody, binding to a specific motif on HLA class I molecules that distinguishes them from those bearing the Bw4 epitope.
• Critical Amino Acids: Site-directed mutagenesis studies demonstrated that a single amino acid substitution at position 83 (G83R) abrogates binding of BB7.6 to HLA-B*07:02, likely due to steric hindrance. This indicates that glycine at position 83 is crucial for BB7.6 recognition.
• Extended Binding Interface: Unlike some other anti-Bw6 antibodies, BB7.6 appears to contact both the ?-1 and ?-2 ?-helices of the HLA molecule. Amino acid substitutions at residues 148 and 150 (located in the ?-2 helix) also affect BB7.6 binding, suggesting that it spans the peptide-binding groove and interacts with both ?-helices.

Epitope Heterogeneity and Antibody Diversity

• Epitope Heterogeneity: The Bw6 epitope (and its counterpart, Bw4) is a family of related structures, recognized by a diverse array of antibodies and natural killer (NK) cell receptors.
• Distinct Binding Profiles: Different anti-Bw6 antibodies have varying sensitivities to mutations. For example, while BB7.6 is sensitive to substitutions at residues 148 and 150 (?-2 helix), other anti-Bw6 antibodies (such as SFR8-B6) are sensitive to mutations elsewhere (e.g., residue 90), indicating that these antibodies contact different surfaces of the HLA molecule, even within the same family of epitopes.

Implications for HLA Typing and Immune Recognition

• Use in HLA Typing: Antibodies like BB7.6 are used to distinguish HLA alleles based on their public epitope groups (Bw4/Bw6), which is important in histocompatibility testing and transplantation.
• Model for Antibody-Antigen Interaction: The findings with BB7.6 highlight that the binding interface between antibody and antigen can be large and involve discontinuous stretches of amino acids, consistent with principles of structural immunology.

Summary Table: Key Features of BB7.6

In summary, clone BB7.6 is a well-characterized anti-Bw6 monoclonal antibody critical for defining HLA class I polymorphisms, with a binding pattern that bridges multiple structural domains of the HLA molecule. Its epitope specificity has been finely mapped, providing insights into the molecular basis of antibody-antigen recognition and the functional diversity of the HLA system.