Anti-Human TCR Vα24-Jα18 (iNKT cell)- Purified in vivo GOLD™ Functional Grade

Clone 6B11 is most commonly used in vivo in mice to identify, track, and analyze human invariant natural killer T (iNKT) cells in humanized or transgenic mouse models that express the human Vα24-Jα18 T-cell receptor (TCR), as native murine cells are not recognized by this antibody.

Essential context and supporting details:

• 6B11 specifically recognizes the invariant CDR3 region of the human Vα24-Jα18 TCR, a definitive marker for human iNKT cells.
• It does not stain or react with mouse iNKT cells or conventional murine T cells under normal conditions. Its in vivo use in regular wild-type mice is therefore essentially limited.
• Its principal in vivo applications in mice are in:
  • Transgenic mice or humanized mice engineered to express the human invariant iNKT TCR (and sometimes human CD1d), such as the VαKI model. In these mice, 6B11 can be used to:
    • Detect, enumerate, and localize human iNKT cells in blood and tissues by flow cytometry and immunohistochemistry.
    • Monitor expansion, persistence, and trafficking of adoptively transferred or endogenous human iNKT cells in therapeutic, cancer, or immunological studies.
    • Evaluate immune responses to glycolipid antigens, vaccine candidates, or immunotherapies, as these models respond to stimulation similarly to humans.
• The antibody may also facilitate isolation and purification of iNKT cells for functional assaying and downstream analysis.
• It has ex vivo utility in, for example, cytometric analysis of tissues from mouse models in which human iNKT cells have been engrafted or developed.

Limitations and special notes:

• 6B11 is not reactive with rodent iNKT cells or conventional mouse TCR repertoires; effectiveness is strictly in the context of mice with a humanized iNKT TCR.
• The antibody is essential for distinguishing human iNKT cells from background mouse lymphoid populations in chimeric or humanized models—a critical need for translational research.

In summary, the most common in vivo application of clone 6B11 in mice is to monitor, quantify, and analyze human iNKT cells within humanized or transgenic models, particularly for immunological research and preclinical development of iNKT cell-targeted therapies.

The 6B11 antibody is widely used to identify human invariant natural killer T (iNKT) cells by recognizing the unique invariant TCR Vα24-Jα18 chain. In published studies and core protocols, 6B11 is most commonly used in combination with a standard panel of antibodies and proteins to further define iNKT cells and their functional or developmental subsets. The most commonly used molecules and antibodies with 6B11 include:

• CD3: A universal T cell marker, used to confirm that the 6B11+ cells are indeed T lymphocytes.
• TCR Vβ11: This TCR beta chain is most frequently paired with the Vα24-Jα18 chain in human iNKT cells. Co-staining for Vβ11 helps further enrich for canonical iNKT cells.
• CD4 and CD8: Used to delineate iNKT cell subsets (CD4+, CD8+, double negative) for phenotyping and functional studies.
• CD161 (NKRP1A): Commonly included because many human iNKT cells co-express this NK cell marker, distinguishing them from other T cells.
• CD1d Tetramers (α-GalCer-loaded): While not an antibody, these MHC class I-like molecules loaded with glycolipid antigens are used in parallel or together with 6B11 to specifically identify iNKT cells by their antigen specificity, offering a complementary approach to surface TCR detection.
• Cytokine antibodies (e.g., IFN-γ, IL-4, IL-13): Intracellular staining for cytokines measures the functional responses of iNKT cells after stimulation.
• Viability dyes: Frequently paired for dead cell exclusion in flow cytometry panels.

For multiparametric flow cytometry, 6B11 is typically used in combination with fluorochrome-conjugated versions of the above antibodies/proteins for higher-resolution analysis of iNKT cell frequency, phenotype, and function.

In summary, CD3, TCR Vβ11, CD4, CD8, CD161, and CD1d tetramers are the most common reagents used alongside 6B11 to characterize human iNKT cells in the literature.

Clone 6B11 is a monoclonal antibody developed for the specific identification and characterization of human invariant natural killer T (iNKT) cells based on their canonical TCR α-chain (Vα24Jα18). Key scientific findings from citations involving clone 6B11 are as follows:

• Specificity and Utility:
  6B11 binds specifically to the invariant CDR3 loop of the human Vα24Jα18 TCR α chain, allowing for highly accurate phenotypic identification and quantification of iNKT cells in human samples. Studies confirm its utility in detecting iNKT cells, providing up to 95% overlap with CD1d tetramer-reactive CD1-restricted T cells.

• Enrichment and Isolation:
  The use of 6B11 enables significant enrichment of iNKT cells, allowing researchers to isolate nearly 90% pure populations from peripheral blood, greatly facilitating downstream molecular and functional studies.

• Characterization of Subsets:
  With 6B11, four stable iNKT cell subsets have been characterized in peripheral blood (CD4+, CD8+, double negative, and others), revealing distinct phenotypic and functional profiles. Notably, CD8+ iNKT cells preferentially express LAG-3, distinguishing them from other subsets.

• Functional Insights and Disease Association:
  6B11 studies show a strong negative correlation between total iNKT cell frequency and the percentage of the CD4+ subset. In patients at risk for type 1 diabetes, frequencies of double negative iNKT cells are significantly expanded. CD4+ iNKT cells are the highest producers of IL-4, whereas IFN-γ and TNF-α production is similar across subsets, suggesting the ratio of iNKT cell subsets might influence susceptibility to immune-mediated diseases.

• Comparison to Other Markers:
  6B11 provides a more precise definition of human iNKT cells compared to other markers such as CD1d tetramer, Vα24 alone, or Vβ11, which can lead to overlap or misidentification due to non-invariant populations or technical limitations.

• Applications in Flow Cytometry and Research:
  6B11 is widely used in flow cytometric protocols for reliable quantification and characterization of iNKT cells in both research and clinical contexts, as reported in flow cytometry method comparisons and standardization efforts.

• Cross-reactivity and Limitations:
  6B11 can cross-react with iNKT cells from old-world non-human primates but not with rodent iNKT cells, limiting its comparative use in small animal models.

In summary, clone 6B11 is a gold-standard tool for human iNKT cell identification, enabling advances in immunological research, subset analysis, and disease association studies due to its high specificity for the invariant TCR α-chain rearrangement.

Based on the available information, specific dosing regimens for clone 6B11 in different mouse models are not comprehensively documented in the current literature. Clone 6B11 is a monoclonal antibody that targets the invariant TCR Vα24Jα18 expressed on invariant Natural Killer T (iNKT) cells, but detailed dose-response studies across various mouse models remain limited.

Available Dosing Information

The primary dosing data for iNKT cell-targeting antibodies comes from studies using related clones rather than 6B11 specifically. For example, studies with NKTT120, a humanized monoclonal antibody targeting iNKT cells, have established dosing regimens in cynomolgus monkeys ranging from 0.3 to 10 mg/kg administered weekly for five consecutive weeks. However, these primate studies do not directly translate to mouse model dosing recommendations for clone 6B11.

Factors Influencing Dosing Variations

Dosing regimens for iNKT cell-targeting antibodies like 6B11 vary based on several key factors:

Model-specific considerations play a significant role, as the extent of tissue iNKT cell depletion required can differ substantially between models. Studies indicate that the dose needed to significantly deplete total tissue iNKT cells is approximately 10-fold higher than that necessary to produce total blood depletion.

Frequency and duration of administration also impact outcomes. Higher doses tend to produce more variable recovery responses, with iNKT cell reappearance occurring at different timepoints depending on the initial dose administered.

Current Research Gaps

The literature acknowledges that dosing regimens for clone 6B11 primarily vary by dose amount, frequency, and mouse model context, but comprehensive protocols detailing these variations across specific tumor models, infection models, or autoimmune disease models are not readily available. Researchers typically need to optimize dosing empirically based on the specific experimental objectives and the mouse strain being used.

For practical applications, flow cytometry studies suggest that 6B11 can be used at less than or equal to 1 μg per test for in vitro applications, though in vivo dosing would require substantially higher amounts based on standard antibody pharmacokinetics in mice.