Anti-Human CD4 (Clone OKT-4) – Purified in vivo GOLD™ Functional Grade

Based on the search results provided, there is limited specific information about how the OKT-4 clone is used in in vivo mouse studies. The search results primarily focus on other research areas, with only brief mentions of the OKT-4 antibody.

Available Information on OKT-4

The OKT-4 clone is a mouse monoclonal antibody that specifically reacts with human CD4. This antibody has been validated for use in multiple applications including western blotting, immunofluorescence, and flow cytometry. The antibody is available in different formats, including PE-conjugated versions for flow cytometry applications.

Potential Applications in Mouse Studies

While the search results don't provide detailed protocols for in vivo mouse studies using OKT-4, the antibody's specificity for human CD4 suggests it would typically be used in research involving:

• Humanized mouse models where human CD4+ T cells have been engrafted
• Xenograft studies involving human immune cells
• Studies examining human CD4+ T cell function in mouse recipients

The fact that OKT-4 is specifically designed to react with human CD4, rather than mouse CD4, indicates that its primary utility in mouse studies would be for tracking, depleting, or analyzing human CD4+ T cells that have been introduced into mouse models.

However, the search results do not contain sufficient detail about specific experimental protocols, dosing regimens, administration routes, or applications in particular disease models using the OKT-4 clone in mouse studies. More comprehensive research literature would be needed to provide detailed information about its specific uses in in vivo mouse research.

Commonly used antibodies and proteins with OKT-4 (anti-human CD4) in the literature include markers for other T cell subsets, activation states, and immune cell populations—such as CD3, CD8, CD25, CD45RA/RO, and CD14.

In typical immunological studies and flow cytometry panels, some of the most frequent companion antibodies and markers to OKT-4 include:

• CD3: This is a pan-T cell marker commonly used to identify total T cell populations, enabling distinction between helper (CD4+) and cytotoxic (CD8+) T cells when used with OKT-4.
• CD8: Used to identify cytotoxic T cells; helps distinguish CD4+ (helper) from CD8+ (cytotoxic) T cell subsets in mixed populations.
• CD25: Marks activated T cells, including regulatory T cells (Tregs) when used in conjunction with CD4.
• CD45RA and CD45RO: Used to differentiate naive and memory T cell subsets within the CD4+ population.
• CD14: A monocyte marker, sometimes included to exclude monocytes, further refining lymphocyte gating (since CD4 can be expressed at lower levels on monocytes/macrophages).

OKT-4 is sometimes compared or combined with other anti-CD4 clones, such as RPA-T4, since they recognize different epitopes on the CD4 molecule and can be used together in multiplex assays or competition experiments.

For functional or activation studies, antibodies against surface markers and cytokines (such as IFN-?, IL-2, FoxP3 for Tregs, and CD69/CD62L) are commonly co-used.

In summary, CD3, CD8, CD25, CD45RA/RO, and CD14 are among the most commonly used markers with OKT-4 in immunology literature and flow cytometry. Clones like RPA-T4 are often used for epitope discrimination and experimental controls.

Key findings from scientific literature involving clone OKT-4 (more accurately referred to as anti-CD4 monoclonal antibody, clone OKT4) center on its use in immunology for identifying and functionally characterizing CD4+ T lymphocyte populations, particularly in the context of cytotoxic T lymphocyte (CTL) activity and antigen recognition.

Core findings include:

• OKT4+ T Cell Definition: The OKT4 antibody recognizes the human CD4 molecule, a key surface marker expressed on T helper cells (CD4+ T cells).

• Functional Cloning and Specificity: In a landmark study, OKT4+ cytotoxic T lymphocytes were cloned via limiting dilution. Analysis of these clones showed that:

  • Both assessed clones (B8 and C6) were OKT3+, OKT4+, and OKT8-, confirming their CD4+ phenotype rather than CD8+.
  • These clones had specificity for HLA-DR antigens: clone B8 recognized DR6 in a target-specific manner, while clone C6 recognized a "supratypic" determinant present on some DR3, DR5, and DR6 alleles, likely corresponding to a broader or alternative Ia-like structure.
  • Monoclonal antibody blocking: Both target cell recognition and cytolytic activity by these clones could be blocked by anti-OKT3 and anti-OKT4 antibodies, but not anti-OKT8, demonstrating a functional reliance on CD3 and CD4 molecules.
  • Antigen recognition: Panels of monoclonal antibodies identifying DR molecules could block recognition, underlining the critical role of HLA-DR in the target specificity of these CD4+ CTL clones.

• Broader Impact: The availability of OKT4+ (CD4+) CTL clones aids in dissecting the spectrum of Ia-like (MHC class II) antigens recognized by human T cells. This fosters deeper understanding of T cell specificity in immunity and helps clarify the roles of different helper and cytotoxic subsets in human immune responses.

If your query was focused on the OKT-4 (anti-CD4) antibody clone in flow cytometry and immunology, these are the foundational insights. If you meant research on "Oct4" (the transcription factor crucial for pluripotency, sometimes confused with OKT4 due to similar spelling), references and are relevant, but they pertain to developmental biology and not immunology. If you need findings on "Oct4," please clarify for a targeted answer.

Dosing regimens for clone OKT-4 (anti-CD4 monoclonal antibody) in mouse models typically range from 200–250??g per mouse, administered via intraperitoneal injection, given 2–3 times per week, although precise schedules may vary depending on the experimental context and desired extent of CD4+ T cell depletion.

The regimen can be adjusted in:

• Autoimmune models: Frequent dosing may be needed to maintain sustained CD4+ T cell depletion, with 2–3 injections weekly as standard.
• Transplantation and tumor rejection studies: Similar dosing (200–250??g/mouse, 2–3 times weekly i.p.) is common, often in combination with anti-CD8 antibodies to target all T cell subsets.
• Infection models: May use the same doses, but the schedule could be tailored depending on pathogen load and kinetics of immune response.
• Long-term studies: Some protocols extend dosing for several weeks, maintaining regular injections to ensure continuous CD4+ T cell depletion.

Key factors affecting dosing variation:

• Mouse strain and weight: Although dosing is usually per mouse rather than per kilogram, some investigators adjust for larger or smaller animals.
• Route of administration: While i.p. injection is standard, intravenous or subcutaneous routes are rarely used and could require dose modification.
• Study design: Short-term depletion (acute) may use a single or limited doses, while chronic depletion uses repeated dosing.

No major conflicting protocols are reported for clone OKT-4, but dosing guidance is often extrapolated from functionally similar clones (such as GK1.5), as direct peer-reviewed OKT-4 murine usage is less common due to its human/primatized origin; GK1.5 is more frequently used for mouse CD4 targeting.

Thus, while the 200–250??g/injection, 2–3 times weekly regimen is broadly accepted for CD4 depletion in mice, individual studies may tailor for experimental needs, mouse strain, and target depletion kinetics.