CD5 Antibody
Description
Structure and Function of CD5
CD5 is a 67 kDa glycoprotein belonging to the scavenger receptor cysteine-rich (SRCR) superfamily. It features a large extracellular domain and a cytoplasmic tail involved in signal transduction . Key functional roles include:
Diagnostic and Research Applications
CD5 antibodies are widely used in immunohistochemistry (IHC) and flow cytometry to identify specific lymphocyte populations:
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T-cell malignancies: CD5 is a marker for T-cell lymphomas and leukemias .
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B-cell neoplasms: Expressed in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma, aiding differentiation from CD5-negative subtypes .
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Immune profiling: Detects CD5+ regulatory T cells (Tregs) and activated T cells in autoimmune and cancer microenvironments .
Key Antibody Clones
Cancer Immunotherapy
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CAR-T/NK cell therapy:
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Checkpoint inhibition:
Autoimmune Disease Management
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Intravenous immunoglobulin (IVIg) containing anti-CD5 antibodies modulates T-cell function and reduces autoreactive B-cell activity, showing promise in autoimmune therapy .
Clinical Trial Progress
Challenges and Future Directions
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Toxicity: CD5 expression on normal T cells raises risks of on-target/off-tumor effects in CAR-T therapies .
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Mechanistic gaps: The regulatory role of CD5 in dendritic cells (e.g., CD5+ DCs prime T H1/17 responses) remains underexplored .
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Combination strategies: Pairing anti-CD5 antibodies with PD-1/CTLA-4 inhibitors may amplify antitumor efficacy .
Product Specs
Product Science Overview
CD5 belongs to the scavenger receptor cysteine-rich protein superfamily (SRCR) . It plays a crucial role in modulating T and B cell receptor signaling, thymocyte maturation, and T-B cell interactions . The natural ligand for CD5 is CD72 . CD5+ B cells are known to produce polyreactive antibodies, mostly immunoglobulin M (IgM) .
CD5 is primarily expressed on thymocytes, T cells, and B-1 cells . Although mature alpha/beta T cells express high levels of CD5, very few gamma/delta T cells express this antigen . The interaction of CD5 with CD72, gp35-37, T cell receptor (TCR), or B cell receptor (BCR) is involved in T and B cell activation .
CD5 acts as a negative regulator of T-B cell interaction . By setting the threshold level for activation signals, CD5 prevents B cells from activation-induced cell death and maintains tolerance in anergic B cells in vivo . This is crucial for keeping potentially autoreactive cells alive, as these cells are necessary for an effective immune response to some pathogens .
The mouse anti-human CD5 antibody is typically prepared by purifying the antibody through affinity chromatography . The antibody solution is usually stored undiluted between 2°C and 8°C . It is used in various applications such as flow cytometry, immunohistochemistry, and Western blotting .
In flow cytometry, the antibody is used for immunofluorescent staining with flow cytometric analysis . For immunofluorescent staining, it is recommended to use at ≤ 1.0 µg per 10^6 cells in 100 µl volume or 100 µl of whole blood . The reagent should be titrated for optimal performance for each application .
