CDA7 Antibody

What is CD7 and what cellular populations express this marker?

CD7 is a 40 kDa transmembrane, single-chain glycoprotein that belongs to the immunoglobulin gene superfamily. It plays an essential role in T-cell interactions and T-cell/B-cell interaction during early lymphoid development. The expression profile of CD7 includes:

• Majority of immature and mature T-lymphocytes

• Natural killer (NK) cells

• Small subpopulation of normal B-cells

• Certain malignant B-cells

• Majority of mature peripheral T-cells

• Post-thymic T-cells

• Some myeloid cells

Notably, CD7 expression is conspicuously absent in adult T-cell Leukemia/Lymphoma and Sezary cells, making this an important differential diagnostic marker .

What are the validated applications for CD7 antibodies in laboratory research?

CD7 antibodies have been validated for multiple research applications with specific methodological considerations for each:

These applications provide researchers with multiple approaches to study CD7 expression in various experimental contexts, with each method requiring specific optimization steps .

What is the biological function of CDA and what antibodies are available for its detection?

CDA (Cytidine Deaminase) is an enzyme that scavenges exogenous and endogenous cytidine and 2'-deoxycytidine for UMP synthesis. This enzymatic activity is critical for nucleotide metabolism pathways and has implications for drug metabolism, particularly for nucleoside analogs used in cancer treatment .

CDA antibodies for research include:

These antibodies have been validated for immunohistochemical applications, with recommended dilutions of 1:100 for paraffin-embedded tissues, such as gastric carcinoma xenografts .

How do researchers quantitatively assess CD7 antibody affinity and what parameters indicate superior candidates for therapeutic development?

Assessing CD7 antibody affinity requires rigorous biophysical characterization. Researchers typically employ Surface Plasmon Resonance (SPR) techniques such as Biacore assays to determine binding kinetics:

Among the tested anti-CD7 antibodies, J87 demonstrated the highest affinity with a KD of 1.54 × 10⁻¹⁰ M, making it a superior candidate for therapeutic applications. For SPR analysis, the extracellular domain of CD7 (CD7-mFc) is typically immobilized on CM5 chips using amine coupling, followed by injection of antibodies in a 2-fold dilution series across the chip .

The equilibrium dissociation constant (KD) values in the 10⁻¹⁰ M range indicate high-affinity interactions, with lower values representing stronger binding. When developing therapeutic antibodies, researchers should prioritize clones with KD values <10⁻⁹ M and evaluate internalization efficiency in parallel .

What methodologies are most effective for evaluating CD7 antibody internalization kinetics in T-cell leukemia models?

Antibody internalization is a critical parameter for developing effective antibody-drug conjugates (ADCs). The following methodological approach provides a robust assessment of internalization kinetics:

• Cell preparation:

  • Culture CD7-expressing cell lines (e.g., CCRF-CEM, Jurkat) in appropriate media

  • Harvest cells in exponential growth phase (viability >95%)

  • Prepare cell suspensions at 1 × 10⁶ cells/mL

• Time-course evaluation:

  • Incubate cells with anti-CD7 antibodies at 0h, 1h, 2h, 4h, and 6h timepoints

  • Maintain consistent temperature (37°C) and antibody concentration

• Detection methods:

  • Flow cytometry: Stain with FITC-conjugated secondary antibody to quantify remaining surface antibody

  • Confocal microscopy: Use fluorescently-labeled antibodies to visualize intracellular localization

This approach revealed that among three tested anti-CD7 mAbs (J87, G73, and A15), J87 demonstrated superior internalization efficiency, which correlated with its higher binding affinity. This combined profile of high affinity and efficient internalization made J87 the optimal candidate for ADC development .

How can researchers develop and validate a CD7-targeting antibody-drug conjugate for T-cell malignancies?

The development of anti-CD7 ADCs follows a systematic process that combines antibody engineering with drug conjugation technology:

A recent study successfully generated J87-Dxd, an anti-CD7 ADC using the topoisomerase I inhibitor Deruxtecan (DXd) conjugated to J87 via a cleavable maleimide-GGFG peptide linker. This ADC demonstrated potent cytotoxicity against CD7-expressing T-ALL cell lines with an IC50 of 6.3 nM against CCRF-CEM cells, highlighting the therapeutic potential of this approach .

What are the optimal conditions for CD7 immunohistochemistry in clinical and research specimens?

Achieving consistent and specific CD7 immunostaining requires careful optimization of multiple parameters:

When performing CD7 IHC, specific staining is primarily localized to the plasma membrane of T-cells. Common tissues used as positive controls include thymus, tonsil, and lymph node, where distinct T-cell zones should show clear membrane positivity .

How should researchers address discrepancies between CD7 detection methods when characterizing novel T-cell populations?

When discrepancies arise between different CD7 detection methods, a systematic troubleshooting approach is essential:

• Method-specific considerations:

  • Flow cytometry detects native conformation on viable cells

  • IHC visualizes fixed epitopes with spatial context

  • Western blot identifies denatured protein by molecular weight

• Validation strategy:

  • Employ multiple antibody clones targeting different CD7 epitopes

  • Include known positive controls (MOLT-4, CCRF-CEM) and negative controls (Raji)

  • Compare results across multiple techniques using standardized samples

  • Quantify expression levels rather than relying on binary positive/negative classification

• Discrepancy resolution:

  • For weak IHC staining with positive flow cytometry: Optimize antigen retrieval conditions

  • For aberrant molecular weight in Western blot: Investigate glycosylation variations (CD7 typically appears at 35-40 kDa)

  • For heterogeneous expression: Increase sample size and evaluate at single-cell resolution

This comprehensive approach allows researchers to reconcile conflicting results and develop a more accurate understanding of CD7 expression in complex cellular populations .

What strategies can overcome common technical challenges when using CDA antibodies for detection in tissue specimens?

Researchers working with CDA antibodies may encounter several technical challenges that require specific optimization approaches:

When working with CDA antibody ab137605, immunohistochemical analysis has been successfully performed on paraffin-embedded gastric carcinoma xenografts at a 1:100 dilution. When optimizing new tissue types, researchers should conduct titration experiments with dilutions ranging from 1:50 to 1:200 to determine optimal signal-to-noise ratio for their specific application .

How does CD7 antibody staining complement other T-cell markers in comprehensive immunophenotyping panels?

Comprehensive T-cell immunophenotyping requires strategic combinations of markers to accurately identify cell subsets and activation states:

When designing multicolor flow cytometry panels, CD7 antibodies can be effectively paired with CD3 to provide a comprehensive assessment of T-cell populations. In research settings, including CD7 alongside lineage markers (CD3, CD4, CD8) and activation markers (CD25, CD69) enables more precise characterization of T-cell functionality .

The distinctive expression pattern of CD7 across different T-cell malignancies makes it a valuable component of diagnostic panels, particularly for distinguishing T-ALL (typically CD7+) from other T-cell leukemias where CD7 expression may be downregulated or absent .

What genomic and post-translational modifications influence CD7 expression and antibody recognition in hematologic malignancies?

CD7 expression in hematologic malignancies is regulated through multiple mechanisms that can affect antibody recognition:

• Transcriptional regulation:

  • Promoter methylation can silence CD7 gene expression in some T-cell malignancies

  • Transcription factor dysregulation in leukemic cells can alter CD7 expression levels

• Post-translational modifications:

  • Glycosylation variations: CD7 is a glycoprotein with variable glycosylation patterns

  • Phosphorylation status may affect protein conformation and epitope accessibility

  • Proteolytic processing can generate variant forms with altered antibody recognition

• Methodological implications:

  • Antibodies targeting different epitopes may show discordant results based on post-translational modifications

  • Detection of glycosylated forms results in the 35-40 kDa band observed in Western blot analysis

  • Certain fixation methods may alter glycan structures, affecting antibody binding

Understanding these modifications is crucial when interpreting CD7 detection results, particularly when comparing findings across different methodological platforms or patient samples .

How can CDA antibody-based research contribute to understanding chemotherapeutic resistance mechanisms?

CDA (Cytidine Deaminase) plays a crucial role in nucleoside metabolism and has significant implications for resistance to nucleoside analog drugs:

• Research applications:

  • Quantification of CDA expression in tumor samples before and after treatment

  • Correlation of CDA levels with response to nucleoside analog drugs (e.g., gemcitabine, cytarabine)

  • Identification of regulatory mechanisms controlling CDA expression in resistant cells

• Methodological approach:

  • IHC analysis of CDA expression in paired sensitive/resistant tumor samples

  • Western blot quantification of CDA protein in cell line models

  • Integration with functional enzyme activity assays to correlate protein levels with catalytic function

• Clinical implications:

  • Potential use as a predictive biomarker for response to nucleoside analog therapies

  • Identification of patients who might benefit from CDA inhibitor combination strategies

  • Development of personalized treatment approaches based on CDA expression profile

CDA antibodies provide researchers with tools to investigate one of the key resistance mechanisms for important classes of chemotherapeutic agents. By combining CDA protein detection with functional studies, researchers can develop a more comprehensive understanding of drug resistance pathways and potential therapeutic strategies to overcome them .