Anti-Human CD5 [Clone UCHT-2] — Purified in vivo Functional GOLD™ Functional Grade

Clone UCHT-2 is a mouse anti-human CD5 monoclonal antibody commonly used in humanized mouse models to specifically target and study human CD5-positive T cells and B cells in vivo. Its primary use in these studies is to deplete, modulate, or trace human CD5-expressing immune cells, enabling analysis of human immune cell function, trafficking, or depletion within a mouse environment.

Essential context for in vivo mouse studies:

• UCHT-2 specifically recognizes human CD5, a 67 kDa transmembrane glycoprotein present on most human thymocytes, the majority of peripheral T cells, and a subset of B cells. This specificity allows researchers to interrogate human immune responses in mice engrafted with human hematopoietic or immune cells.
• In vivo applications include:
  • Depletion of human T cells: UCHT-2 can be administered to humanized mice in order to selectively eliminate human CD5+ T cells, helping to study their roles in immune responses, tolerance, or disease models (e.g. autoimmunity, graft-versus-host disease).
  • Cellular tracking and tissue localization: By labeling human CD5+ cells, researchers can analyze cell migration, tissue localization, and compartmentalization using flow cytometry or histology in mouse tissues.
  • Modulation of immune responses: The antibody may be used to alter functional states of human T cells in vivo, such as activation or inhibition, depending on experimental goals.
• Functional Grade Antibody Use: The product description from Leinco specifically mentions that UCHT-2 is available in a “Functional GOLD™” grade for in vivo studies, indicating it is purified and formulated to minimize adverse effects (such as endotoxin contamination) and maximize functional efficacy in live animal models.

Additional relevant information:

• UCHT-2 is a mouse IgG1 isotype.
• Species cross-reactivity is highly selective for human CD5—it does not cross-react with mouse CD5, making it ideally suited for distinguishing human cells in mouse models.
• Humanized mouse platforms, such as those described for studying human immunity and antibody responses, frequently use such antibodies to probe specific human leukocyte subsets in vivo for therapeutic and mechanistic studies.

In summary, UCHT-2 is used in vivo in mouse studies to identify, deplete, or modulate human CD5+ T and B cells in humanized mouse models, supporting investigations in immunology, cell therapy, and disease modeling.

The UCHT-2 antibody specifically targets CD5, a surface marker found on T cells and a subset of B cells. In the scientific literature, when UCHT-2 (anti-CD5) is used, it's commonly part of multicolor flow cytometry panels or immunophenotyping assays alongside several other antibodies and markers to distinguish and subclassify lymphocyte populations or analyze immune cell states.

Frequently used antibodies or proteins in combination with UCHT-2 include:

• Anti-CD3 (e.g., clone UCHT1): A pan-T cell marker used to broadly define mature T cells. Co-staining with anti-CD3 and anti-CD5 helps further resolve T cell populations and potential T cell abnormalities.
• Anti-CD19 or Anti-CD20: B cell markers; used to distinguish T cells (CD3?CD5?) from the subset of B cells that co-express CD5 (CD19?CD5?, often implicated in certain leukemias and lymphomas).
• Anti-CD4 and Anti-CD8: Markers for helper and cytotoxic T cell subsets, respectively, often used in multicolor panels with anti-CD5 to delineate T cell differentiation and subset frequencies.
• Anti-CD45: A pan-leukocyte marker for gating leukocytes and further refining analysis of T versus B cells in immunophenotyping studies.
• Anti-CD7, CD2, CD56: Additional T/NK cell-related markers that may be included depending on the research or clinical focus.
• Anti-CD22, CD79a/b: Used in some advanced phenotypic or functional screens, especially for B cell studies or bispecific antibody screening, as shown in high-throughput approaches identifying combinations like CD22 and CD79 for modulating B cell activation.

Typical applications using these combinations include:

• Flow cytometry for lymphocyte subset discrimination
• Immunohistochemistry for tissue analysis of lymphoid organs or pathology
• Advanced functional screens for therapeutic antibody target discovery and immune modulation studies

In summary, UCHT-2 (anti-CD5) is most commonly used in conjunction with major T and B cell markers—CD3, CD19, CD20, CD4, CD8, CD45—and, increasingly, with novel or functional markers like CD22 or CD79 in more specialized settings. This approach allows for detailed immune profiling in both basic research and clinical diagnostics.

Summary of Key Findings from Clone UCHT-2 (Anti-CD5 Antibody) in Scientific Literature

Clone UCHT-2 is a widely used monoclonal antibody against human CD5, a 67 kDa glycoprotein expressed on most T lymphocytes, thymocytes, and a subset of B lymphocytes. The antibody has been utilized in research and clinical diagnostics for several decades, with findings spanning immunophenotyping, hematological malignancies, and fundamental immunology.

Specificity and Cellular Localization

• T-cell specific staining: UCHT-2 specifically recognizes human CD5 and is routinely used to identify and characterize human T-lymphocytes in both peripheral blood and tissues.
• B-cell subpopulation reactivity: Importantly, UCHT-2 also reacts with a distinct subset of normal B-lymphocytes, particularly B-chronic lymphocytic leukemia (CLL) cells and some lymphomas.
• Absence on monocytes, granulocytes, and NK cells: The antibody does not stain these cell types, emphasizing its specificity for lymphocytes within the immune system.
• Differential staining intensity: Peripheral blood T-cells typically show strong staining, while thymic T-cells exhibit weaker staining with UCHT-2.

Applications in Research and Diagnostics

• Leukemia and lymphoma characterization: UCHT-2 has been instrumental in the classification of leukemias and lymphomas, particularly for distinguishing CD5+ B-cell malignancies, which are a key diagnostic feature in chronic lymphocytic leukemia.
• Flow cytometry validation: The antibody is validated for flow cytometry, with peripheral blood lymphocytes clearly differentiated by positive staining in flow cytometric profiles.
• Benchmark for other reagents: UCHT-2 is frequently used as a positive control in experimental settings, including the development of novel CD5-targeting reagents.

Technical Notes and Limitations

• Optimal dilution varies: Each investigator must titrate UCHT-2 to determine the best working dilution for their specific application, as optimal conditions can vary with experimental setup.
• Safety considerations: Some commercial preparations contain sodium azide, which is toxic and requires careful handling.

Molecular Insights

• CD5 ligand: CD72 has been identified as the natural physiological ligand for CD5, and UCHT-2 is a tool to study this interaction in immune regulation.
• B-cell polyreactivity: CD5+ B cells targeted by UCHT-2 are known for producing polyreactive antibodies, mostly IgM, which is significant in understanding innate-like B-cell responses.

Conclusion

Clone UCHT-2 is a highly specific and reliable antibody for the identification of human T lymphocytes and CD5+ B-cell subsets, with broad applications in research and clinical diagnostics—especially in hematological malignancy classification, immunophenotyping, and basic immunology studies. It remains a benchmark reagent for studying CD5 biology and its role in human immune cell populations.

Dosing regimens of clone UCHT-2 (an anti-human CD5 monoclonal antibody) in mouse models are not universally standardized and can vary significantly depending on the mouse model, the specific research application, and the protocol design. There is no widely published, fixed dosing regimen for UCHT-2 in mice, as optimal doses and schedules are rarely detailed in vendor documentation or public antibody handbooks.

Most common findings and considerations:

• Clone UCHT-2 recognizes human CD5, so its primary application is in models where mice express human CD5, such as in humanized mouse models (mice reconstituted with human immune cells).

• Vendor recommendations: For in vitro applications, typical working dilutions for flow cytometry are 1:5–1:10 on 10^6 cells. However, such guidance does not directly translate to in vivo dosing, and vendors generally do not provide in vivo dosing instructions for UCHT-2, instead urging users to optimize based on pilot titrations.

• Humanized mouse models: In mice engrafted with human lymphocytes or hematopoietic stem cells, anti-human antibodies, including UCHT-2, may be used to target or deplete human T cells. Protocols published for other human-specific antibodies in humanized mice typically use doses ranging broadly (e.g., 100–500??g per mouse, given intraperitoneally). These numbers serve as a general reference for the class of anti-human immune cell antibodies, but no direct studies on UCHT-2 are cited in standard dosing guides.

• Model/Schedule variability: The route (often intraperitoneal), frequency (weekly or biweekly), and dose amount should be determined by:

  • The fraction of human cell reconstitution in the mouse
  • The specific immune effect desired (depletion, modulation, blocking)
  • Potential for cross-reactivity or off-target effects
  • Observed toxicity and antibody clearance

• Adjustments based on application: When using UCHT-2 for functional studies (e.g., T cell depletion or signaling inhibition) in humanized mouse models, many researchers pilot doses based on the expected in vivo efficacy seen with similar IgG1 antibodies and then optimize as needed.

Key point: Since UCHT-2 is species-specific (human CD5) and not cross-reactive with mouse CD5, it will have little to no effect in wild-type mice and is only functional in humanized or transgenic mice expressing human CD5.

Summary Table: (Example approach to dosing, drawn from broader anti-human antibody guidelines):| Application | Mouse Model Type | Typical Dose (?g/mouse) | Route | Notes ||-----------------------------------|-------------------------|-------------------------|-------------------|----------------------------------------------------------|| Flow Cytometry (ex vivo) | Any | 10 ?l at 1:10 dilution | Cell suspension | For labeling human cells only || In vivo functional (eg depletion) | Humanized mice | 100–500 (pilot range) | Intraperitoneal | Adjust based on reconstitution, efficacy, toxicity || WT mice (no human CD5) | Wild-type, not humanized| Not Effective | n/a | No cross-reactivity with mouse CD5 |

Conclusion: Optimal in vivo dosing of clone UCHT-2 in mouse models must be empirically determined for each setting, guided by protocols for similar anti-human antibodies in reconstituted mice, and should involve titration studies with close monitoring for efficacy and adverse effects. No universal or model-specific regimen for UCHT-2 is available in the peer-reviewed or vendor-supplied literature as of the current date.