Anti-Human IgM µ-Chain Specific (Clone HB57) – Purified in vivo GOLD™ Functional Grade

In in vivo mouse studies, clone HB57 refers to the use of transgenic mice expressing the human HLA-B*57:01 allele to model immune responses and drug-induced liver injury, particularly for studying hypersensitivity reactions to drugs like abacavir and flucloxacillin.

Key applications and context:

• *Transgenic mice expressing HLA-B57:01** (often called "HB57 mice") are generated to precisely model human immune responses that involve this particular HLA allele.
• These mice are typically used to study mechanisms of drug presentation and immune activation by the human risk allele HLA-B57:01*, which is associated with adverse drug reactions (ADRs) such as flucloxacillin (FLX)-induced liver injury and abacavir hypersensitivity.
• In in vivo experiments, these mice are treated with the relevant drug (e.g., FLX). Researchers assess:
  • CD8^+^ T-cell activation—robust drug-specific immune responses occur in mice lacking CD4^+^ T cells or PD-1 expression, leading to cytotoxic infiltrates in the liver.
  • Histopathology and liver tolerance—although immune infiltrates occur, actual liver injury (DILI) is often prevented by tolerogenic mechanisms, such as the presence of CD4^+^ regulatory T cells and PD-1-mediated inhibition.
• Variants of HB57 mouse models lacking endogenous mouse MHC class I, or with knockout of PD-1 or CD4^+^ T cells, are often used to dissect the roles of different immune components and tolerogenic pathways in vivo.
• Experimental protocols include breeding specific HLA-B*57:01 transgenic strains, housing under pathogen-free conditions, and drug administration followed by immunological and histological assessment.

In summary, clone HB57 in mouse studies is a transgenic line expressing HLA-B*57:01, widely used to investigate human-like adaptive immune responses to certain drugs, mechanisms of tolerance, and the cellular basis for HLA-associated hypersensitivity syndromes.

There is no specific information available about the storage temperature for a sterile packaged clone named HB57 in the provided search results. However, for general sterile medical supplies, it is recommended that storage temperatures do not exceed 72°F (22°C) to 78°F (26°C) to maintain sterility and integrity. If HB57 is related to a specific biological product or reagent, such as the IgM Antibody (DA4-4 same as SA-DA4 or HB57), it would typically require storage at lower temperatures, such as refrigeration at 4°C, especially if it is a sensitive biological reagent. It's advisable to consult specific product guidelines or manufacturer recommendations for precise storage conditions.

There is no direct evidence in the provided search results that identifies specific antibodies or proteins commonly used alongside HB57 in the literature. The available information describes HB57 (clone ID) as a monoclonal antibody specific for the human IgM ?-chain constant region (target: Ig mu chain C region, Ig mu chain C region BOT, IGHM), with applications such as flow cytometry (FCM), Western blot (WB), and immunohistochemistry (IHC).

In typical laboratory use, antibodies like HB57 are often paired with reagents that detect different immunoglobulin isotypes (e.g., anti-IgG), secondary antibodies (e.g., anti-mouse IgG for detection of mouse-derived primary antibodies like HB57), or antibodies specific for cellular markers (e.g., CD19 for B cells if studying B cell IgM expression). However, the search results do not cite any specific examples of these pairings or named collaborations of HB57 with other antibodies or proteins in published studies.

In summary:
The search results confirm the use and specificity of HB57 but do not contain information about other antibodies or proteins commonly used in combination with HB57. For such information, you would need to consult primary research articles or review papers in immunology and B cell biology, which often describe multiplex antibody panels in flow cytometry or co-staining experiments.

The clone HB57, specifically in the form of dextran-conjugated anti-? mAb HB57 (HB57-dex), is referenced in scientific literature primarily for its role in B-cell receptor (BCR) stimulation and its impact on telomerase activity and cell survival in B-cell chronic lymphocytic leukemia (B-CLL) clones. Here are the key findings:

1. BCR Stimulation and Telomerase Activity: HB57-dex is used as a multivalent BCR ligand to stimulate B cells. This stimulation increases telomerase activity, which is crucial for cell survival and proliferation, particularly in U-CLL (unmutated IGHV genes) cases compared to M-CLL (mutated IGHV genes) cases.

2. Cell Survival and Proliferation: The study shows that HB57-dex preferentially promotes cell survival and proliferation in U-CLL clones. In contrast, M-CLL clones exhibit similar membrane-proximal signaling responses but do not show significant increases in telomerase activity or cell survival.

3. Comparison with Bivalent Ligands: When compared to bivalent F(ab?)2 goat anti-? antibodies, HB57-dex induces higher telomerase activity and better cell survival outcomes. The bivalent ligand causes a significant Ca2+ flux but does not translate into increased proliferation or telomerase activity in M-CLL clones.

4. Signaling Pathways: The PI3K/Akt inhibitor LY294002 blocks the telomerase activation induced by HB57-dex, indicating that the PI3K/Akt pathway is involved in BCR-mediated telomerase up-regulation.

These findings highlight the importance of valency and ligand structure in BCR signaling and its downstream effects on telomerase activity and cell fate in B-CLL clones.