CD57 Biotin Antibody

What is CD57 and why is it important in immunological research?

CD57 (also known as HNK-1, NK-1, Leu-7, or B3GAT1) represents a 110 kDa oligosaccharide antigenic determinant present on various polypeptides, lipids, and chondroitan sulfate proteoglycans. It is expressed on approximately 7-35% of normal peripheral blood lymphocytes, including significant subsets of natural killer cells and CD8+ T lymphocytes . The importance of CD57 in immunological research stems from its role as a cell surface marker that helps identify specific immune cell populations involved in various biological processes.

The carbohydrate epitope is expressed on multiple cell adhesion molecules within the nervous system, suggesting its significance in cell-cell and cell-substrate interactions . CD57 serves as a valuable marker for monitoring immune cell dynamics, particularly in contexts of chronic immune activation, aging, and various pathological conditions including viral infections, autoimmune disorders, and cancer.

What are the primary applications of CD57 Biotin Antibody in laboratory research?

CD57 Biotin Antibody has diverse applications across multiple research methodologies:

The biotin conjugation provides versatility in detection systems, allowing for amplification through streptavidin-based secondary detection methods, which is particularly valuable for analyzing cells expressing low levels of CD57 .

How should CD57 Biotin Antibody be stored and handled to maintain optimal reactivity?

For optimal performance of CD57 Biotin Antibody in research applications, adherence to proper storage and handling protocols is essential:

• Recommended storage temperature: 2-8°C (refrigerated, not frozen)

• Buffer formulation: Typically provided in phosphate buffered saline containing <0.1% sodium azide or Tris Buffer, pH 7.3-7.7, with 1% BSA

• Avoid repeated freeze-thaw cycles which can compromise antibody integrity

• Centrifuge the vial briefly before opening to ensure recovery of all material

• Working dilutions should be prepared fresh before use for optimal performance

• Follow manufacturer-specific recommendations for each application

When handling the antibody, always wear appropriate personal protective equipment, especially considering the sodium azide preservative commonly present in antibody preparations, which is toxic at high concentrations.

How does CD57 expression correlate with T cell functionality and replicative potential?

Contrary to some published literature suggesting CD57 is a definitive marker for replicative senescent T cells, recent research demonstrates that CD8hiCD57+ T cells retain significant proliferative capacity under appropriate stimulation conditions . These cells show distinct functional characteristics:

• CD8hiCD57+ T cells can proliferate robustly when stimulated with plate-bound anti-CD3 antibodies in the presence of high concentrations of IL-2

• They produce significant levels of proinflammatory cytokines including IFN-γ and TNF-α

• Unexpectedly, CD8hiCD57+ cultures contain substantial amounts of IL-5, particularly after 4+ days of stimulation

• IL-5 production is dependent on both anti-CD3 signal strength and exogenous IL-2 concentration

• Intracellular cytokine staining reveals that the IL-5-producing population is distinct from the IFN-γ-producing population within CD8hiCD57+ cells

Critical methodological factors affecting CD8hiCD57+ T cell proliferation include:

• Culture duration (optimal observation at 5-8 days rather than 48 hours)

• Exogenous cytokine levels (requiring higher IL-2 concentrations)

• Serum type (human AB serum supports proliferation whereas fetal calf serum severely impairs it)

These findings necessitate careful reconsideration of CD57 as a marker of terminal differentiation in T cells, particularly when interpreting functional studies.

What role does CD57 expression play in neuroblastoma progression and tumor biology?

CD57 expression defines a functionally distinct subpopulation in neuroblastoma with significant implications for tumor progression. CD57high neuroblastoma cells display several aggressive characteristics compared to their CD57low counterparts:

• Decreased tumor latency after orthotopic transplantation into adrenal glands of mice

• Enhanced clonogenic potential and sphere formation capacity

• Reduced lineage restriction, suggesting a less differentiated phenotype

• Improved attachment to endothelial cells and increased invasiveness

• Capability to generate liver metastases after tail vein injection

In patient samples, CD57high cells are associated with undifferentiated tumor cells across all disease stages and tend to be more frequent after chemotherapy . These findings suggest CD57 may serve as both a biomarker and potential therapeutic target in neuroblastoma.

The invasion capacity of CD57high neuroblastoma cells appears to be cell line-dependent, as blocking antibodies against CD57 inhibited invasion in U-NB1 cells but not in SK-N-BE(2)-C cells . This highlights the complexity of CD57's role in different neuroblastoma contexts and the need for cell line-specific validation in experimental models.

What are the technical considerations for optimizing CD57 Biotin Antibody staining in multiparameter flow cytometry?

When incorporating CD57 Biotin Antibody into multiparameter flow cytometry panels, several technical considerations must be addressed:

• Panel design: When using biotin-conjugated CD57 antibodies, avoid other biotin-conjugated antibodies in the same panel to prevent cross-reactivity. Consider the following panel components:

  • Streptavidin-fluorophore conjugate selection based on expression level (brighter fluorophores for lower expressed markers)

  • Inclusion of appropriate lineage markers (CD3, CD8, NK markers) for proper subset identification

  • Avoidance of spectral overlap with the streptavidin-fluorophore

• Clone selection: Different anti-CD57 clones may have varying specificities and sensitivities:

  • NK-1 clone: Widely used for identifying CD57+ lymphocyte subsets

  • HNK-1 clone: Alternative option with similar specificity profiles

• Blocking and compensation:

  • Implement Fc receptor blocking to reduce non-specific binding

  • Include appropriate isotype controls (Mouse IgM-BIOT for NK-1 and HNK-1 clones)

  • Perform single-stain compensation controls for each fluorophore

• Staining protocol optimization:

  • Two-step staining process required (primary biotin antibody followed by streptavidin-fluorophore)

  • Titrate both the primary antibody and streptavidin-fluorophore to determine optimal concentrations

  • Consider longer incubation times (30-45 minutes) at 4°C for each step

  • Include washing steps between primary and secondary staining to reduce background

• Data analysis strategies:

  • Use biexponential display scales for proper visualization of CD57 populations

  • Consider analyzing CD57 expression as a continuous variable rather than discrete positive/negative populations

  • Correlate CD57 expression with functional parameters for comprehensive analysis

How can CD57 Biotin Antibody be effectively utilized in immunohistochemistry of different tissue types?

Optimizing CD57 Biotin Antibody staining for immunohistochemistry requires careful consideration of tissue-specific factors:

• Tissue preparation and antigen retrieval:

  • For formalin-fixed paraffin-embedded (FFPE) tissues: Heat-induced epitope retrieval methods are typically required

  • For frozen sections: Acetone or paraformaldehyde fixation protocols are generally suitable

  • Optimal dilution range for paraffin sections: 1:100-1:200

• Detection systems:

  • Streptavidin-HRP or streptavidin-AP systems provide signal amplification

  • The multi-step visualization process enhances sensitivity for detecting CD57 antigens in tissue sections

  • Consider tyramide signal amplification for tissues with low CD57 expression

• Tissue-specific considerations:

  • Tonsil tissue serves as an excellent positive control

  • Neuronal tissues require careful blocking of endogenous biotin

  • Tumors may require titration of antibody concentration due to variable CD57 expression levels

• Special applications:

  • Dual immunostaining with other markers (e.g., CD8, CD3) helps identify specific lymphocyte subpopulations

  • Quantitative image analysis can provide objective assessment of CD57+ cell densities

  • Serial section analysis can help correlate CD57 expression with other biomarkers

The visualization of CD57 antigen in tissue sections is accomplished through a multi-step immunohistochemical staining process, typically employing either horseradish peroxidase (HRP) or alkaline phosphatase (AP) linked detection systems . This approach allows for the spatial assessment of CD57+ cells within the tissue architecture and their relationship to other cellular components.

How do experimental conditions affect the proliferative capacity of CD57+ lymphocytes?

The controversial findings regarding CD57+ lymphocyte proliferation can be reconciled by understanding the critical influence of experimental conditions:

These findings highlight the importance of standardized methodologies when studying CD57+ lymphocyte populations. The previously reported impaired proliferation of CD8hiCD57+ cells may be attributable to suboptimal culture conditions rather than an intrinsic cellular property . Researchers must carefully consider these variables when designing experiments to evaluate the functional properties of CD57+ cells.

What emerging applications exist for CD57 Biotin Antibody in cancer research and immunotherapy development?

CD57 Biotin Antibody has growing applications in cancer research and immunotherapy development, particularly in:

• Tumor microenvironment analysis:

  • Identification and quantification of tumor-infiltrating CD57+ lymphocytes as potential prognostic biomarkers

  • Spatial distribution mapping of CD57+ cells relative to tumor cells and other immune populations

  • Assessment of CD57 expression on tumor cells themselves, as in neuroblastoma

• Immune checkpoint therapy response prediction:

  • Evaluation of CD57 as a potential biomarker for immunotherapy response

  • Correlation of CD57+ cell frequencies with clinical outcomes after checkpoint inhibitor treatment

  • Integration of CD57 into multiparameter immune profiling panels for comprehensive immune status assessment

• Novel therapeutic target identification:

  • CD57high neuroblastoma cells show enhanced tumorigenic and invasive properties

  • Targeting CD57-dependent pathways may provide new therapeutic strategies

  • CD57-blocking approaches may inhibit invasion in certain tumor contexts

• Cell-based therapy development:

  • Monitoring CD57 expression on adoptively transferred T cells to track differentiation status

  • Selection or depletion of CD57+ populations for optimized cell therapy products

  • Assessment of CD57 dynamics as a biomarker of T cell exhaustion or persistence

The diverse roles of CD57 in tumor biology and immune cell function position it as a valuable marker for both basic and translational cancer research, with potential implications for developing novel diagnostic and therapeutic approaches.