Anti-Human CD8 [Clone UCHT-4] — Purified in vivo GOLD™ Functional Grade

Clone UCHT-4 is a mouse monoclonal antibody specific to the human CD8 antigen, and its common in vivo applications in mice are primarily in studies involving humanized or xenograft mouse models containing human immune cells.

Key applications include:

• Depletion of human CD8+ T cells: UCHT-4 is used to selectively deplete or block human CD8+ T lymphocytes in vivo, allowing researchers to assess the role of these cells in immune responses, cancer immunotherapy studies, graft-versus-host disease (GVHD) models, and infectious disease models that use human immune system mice.

• Functional studies of human CD8+ T cell responses: In humanized mice (mice engrafted with human immune cells), UCHT-4 can be used to interrogate human CD8+ T cell-mediated pathways such as cytotoxicity, immune regulation, and antibody interactions in a living organism.

• Assessment of therapeutics targeting human CD8+ lymphocytes: The antibody enables in vivo testing of candidate drugs or biologics intended to modulate or eliminate human CD8+ T cells by simulating therapeutic depletion or checkpoint blockade settings.

• Control or comparison in immunodeficient mouse models: UCHT-4 helps confirm the specificity or effectiveness of human cell engraftment by enabling detection and manipulation of the human CD8+ population within the mouse, facilitating studies on tumor rejection, viral infections, and vaccine efficacy.

Limitations:

• UCHT-4 does not react with murine CD8, so it is only useful in mice containing human CD8+ cells, not for manipulation or depletion of mouse CD8+ populations.
• Its in vivo use is generally restricted to xenograft and humanized immune system mouse models.

The antibody is not used for immune cell manipulation in wild-type mice or for any mouse-specific cell depletions, for which anti-mouse CD8 clones (e.g., YTS 169, 53-6.7) are required.

Commonly used antibodies or proteins paired with UCHT-4 (a monoclonal antibody against human CD8) in the literature are other monoclonal antibodies or detection reagents that target related markers, especially in immunology and flow cytometry experiments.

In experimental contexts, the following are frequently used together with UCHT-4:

• CD3 antibodies (e.g., UCHT1, OKT3): For identifying total T cells, often combined with CD8 (UCHT-4) to distinguish cytotoxic T cell subsets.
• CD4 antibodies: Used to separate helper T cells (CD4^+) from cytotoxic T cells (CD8^+). This provides a comprehensive analysis of T cell populations.
• CD45 or other leukocyte/common lineage markers: To confirm cell identity and exclude non-T cells, increasing data accuracy.
• HIV Env, Tau protein, or other antigens: In specialized research, as targets for functional assays or validation of immune responses.
• Viability dyes and intracellular markers: For assessing live/dead status or functional protein expression within CD8^+ T cells.

In flow cytometry or cell sorting, these combinations enable multi-parametric analysis:

• UCHT-4 (CD8) for cytotoxic T cells.
• Anti-CD3 (UCHT1 or OKT3) for total T cells.
• Anti-CD4 for helper T cells.
• Additional functional markers, such as cytokine antibodies (IFN-γ, IL-2), may be included for profiling T cell responses.

These antibodies are often conjugated to different fluorochromes to distinguish them during multiplexed assays. The exact panel depends on the experimental question, but CD3 and CD4 are the most common co-used antibodies with UCHT-4 in immunological studies.

Clone UCHT-4 is a monoclonal antibody widely cited in scientific literature for its specificity to human CD8, predominantly marking cytotoxic T cells and some regulatory T cell subsets. The principal findings from publications citing UCHT-4 include:

• Reliable detection of CD8+ T cells: UCHT-4 enables selective identification and quantification of human CD8+ T lymphocytes, facilitating immunophenotyping in flow cytometry, immunohistochemistry, and other immunological assays.

• Functional analyses of cytotoxic T cells: Studies using UCHT-4 have characterized the roles of CD8+ T cells in immune responses, disease states, and both normal and malignant hematopoiesis.

• Isotype specification and utility: UCHT-4 is commonly derived as a mouse IgG2a isotype monoclonal antibody, providing robust affinity and minimal cross-reactivity, making it standard for human immune cell profiling.

• Contribution to leukocyte typing: UCHT-4 has featured prominently in seminal works on leukocyte typing and standardization of immunological reagents, laying the foundation for modern cellular immunology.

• Support for clinical and basic research: The antibody is foundational in research on autoimmune disease, HIV/AIDS, cancer immunology, and transplantation, where accurate CD8+ cell enumeration is critical.

Key publications that cite UCHT-4 have reinforced its status as a benchmark reagent for defining CD8+ lymphocytes in human samples, supporting its widespread adoption in research and diagnostics.

No significant alternative or conflicting uses of clone UCHT-4 are described in the indexed search results. Its main scientific impact derives from its reliable specificity and utility in immunological studies targeting human CD8+ T cells.

Dosing regimens for clone UCHT-4 (an anti-human CD8 monoclonal antibody) in mouse models are not explicitly detailed in the provided search results, and published protocols are limited compared to more common depleting clones such as GK1.5 (anti-CD4) and 2.43 (anti-CD8α) used in mice. However, general principles can be inferred:

• Antibody Dosing for Human Targets in Humanized Mice: Antibodies like clone UCHT-4, which target human CD8, are typically applied in humanized mouse models (mice engrafted with human immune cells). Dosing in these models often mirrors regimens established for related anti-human or anti-mouse antibodies, though pilot experiments are used to confirm efficacy due to variability in antibody clearance and bioavailability in vivo.

• Typical Regimens for Depleting Antibodies in Mouse Models: For anti-mouse CD8 depleting antibodies (like clone 2.43), typical regimens are 200–250 μg per mouse, administered intraperitoneally 2–3 times per week. For antibodies against human CD8 in humanized models, initial dosing often starts with matching or slightly higher dose ranges given the potential for faster clearance and the need to ensure full depletion.

• Dosing Adjustments Across Mouse Models:

  • In NSG or NOG immunodeficient mice engrafted with human PBMCs, doses of 100–500 μg per mouse, administered intraperitoneally or intravenously, every 3–4 days are cited as a starting point in the absence of specific UCHT-4 guidance. The precise schedule and number of doses often depends on the experiment’s readout (e.g., complete depletion, functional blockade, or partial modulation).
  • Frequency and Duration: Dosing can be increased (split or more frequent injections) if antibody half-life is short due to rapid clearance by the murine host.
  • Pilot Studies: Pilot dosing and functional validation (e.g., by flow cytometry of human CD8 T cells in blood or spleen) are recommended to fine-tune the regimen for each model or experimental goal.

• Reported Examples: While direct published examples of clone UCHT-4 regimens are scarce, the approach typically follows the general protocol for T-cell depleting monoclonal antibodies:

  • Dose: 100–500 μg per mouse (as referenced for similar anti-human T cell mAbs).
  • Route: Intraperitoneal (IP) or intravenous (IV) injection.
  • Interval: Every 3–7 days, depending on required depletion kinetics and antibody half-life.

Summary Table:

• Key differences between regimens depend on:
  • Xenogeneic vs. syngeneic models (human antibody in mouse vs. mouse antibody in mouse).
  • Mouse strain (immunodeficient vs. immunocompetent).
  • Engraftment and persistence of human cells.

No direct, controlled, comparative studies of clone UCHT-4 dosing regimens across different mouse models are present in the search results. Most laboratories optimize based on depletion efficiency, host strain, and antibody pharmacokinetics in a given model, generally starting from regimens published for analogous monoclonal antibodies.

If you have a specific mouse model or experimental context (e.g., depletion of human CD8+ T cells in NSG mice engrafted with human PBMCs), this would enable a more tailored dosing guidance.