Anti-Mouse CD8b.2 [Clone 53-5.8] — Purified in vivo PLATINUM™ Functional Grade

Clone 53-5.8 is most commonly used in vivo in mice to achieve selective depletion of CD8⁺ T cells by targeting the CD8β chain, which is a component of the CD8 coreceptor primarily expressed on cytotoxic T lymphocytes. This function enables researchers to study the roles of CD8⁺ T cells in immunity, infection, tumor surveillance, transplantation, and autoimmune disease models.

Key in vivo applications include:

• CD8⁺ T cell depletion: Administration of clone 53-5.8 in mice results in robust elimination of peripheral CD8⁺ T cells, with high specificity for the CD8β chain, thereby sparing CD8⁺, CD11c⁺ dendritic cells.
• Functional immune studies: By depleting CD8⁺ T cells, researchers can dissect the specific contribution of these cells to various immune responses, including responses to infection, vaccination, tumor challenge, and transplant acceptance or rejection.
• Immunotherapy and memory cell research: Depletion with clone 53-5.8 allows comparison of the roles and functions of CD8⁺ T cells in primary or recall responses and is sometimes used to compare with CD8α depletion (which can have different immunologic effects).

Additional context:

• Superiority for depletion: Evidence shows that clone 53-5.8 (anti-CD8β) is more efficient at depleting CD8⁺ T cells in vivo than anti-CD8α antibody clones.
• Caveats: Residual CD8⁺ T cells that survive depletion can exhibit altered phenotypes and functions, possibly with enhanced cytotoxic capacity.
• Alternative uses: While its main application is depletion in vivo, 53-5.8 is also used for in vitro blocking and immunofluorescence studies, though these are not in vivo contexts.

In summary, the principal in vivo use of clone 53-5.8 in mice is for selective CD8⁺ T cell depletion to enable precise functional studies of cell-mediated immunity.

Commonly used antibodies or proteins with 53-5.8 (anti-mouse CD8b.2) in the literature include key markers for defining T cell subsets and broader immune cell characterization. The most frequent companions are:

• Anti-CD8α (commonly clone 53-6.7 or 53-6.72): Used to distinguish CD8a/b heterodimers from CD8a homodimers and for comprehensive CD8+ T cell analysis.
• Anti-CD3: Identifies all T cells by targeting the T-cell receptor complex.
• Anti-CD4: Labels helper T cell subsets, often to separate from cytotoxic CD8+ populations.
• Anti-CD45: A pan-leukocyte marker, useful for general immune profiling or gating in flow cytometry.
• Anti-CD11c: Sometimes used when characterizing dendritic cell populations, as some dendritic cells are CD8+.

These antibodies help distinguish CD8+ T cell subsets, segment T cell populations in flow cytometry, and support studies of cytotoxic cell functions. They are often combined in multicolor panels for murine immunophenotyping or T cell depletion experiments.

Clone 53-5.8 is a monoclonal antibody targeting mouse CD8β used extensively in immunology research for selective depletion of CD8+ T cells in vivo, with multiple studies highlighting its superior efficacy and diverse experimental outcomes.

Key findings from scientific literature citing clone 53-5.8 include:

• High Depletion Efficiency: Clone 53-5.8 exhibits a high efficiency in depleting CD8+ T cells, outperforming other anti-CD8 monoclonal antibodies such as clone 53-6.72, making it a gold standard for mouse CD8+ T cell depletion.

• Effects on Pulmonary Injury and Disease Models: In malaria models, administration of clone 53-5.8 reduced pulmonary vascular leakage and protected mice from experimental cerebral malaria (ECM), without affecting parasitemia levels. This demonstrates that the antibody can selectively mitigate CD8+ T cell-mediated tissue injury and improve survival during infection.

• CD8+ T Cell Function Post-depletion: Residual CD8+ T cells, when present after clone 53-5.8-mediated depletion, may possess enhanced cytotoxic capability and altered surface marker expression, indicating effects on T cell function beyond mere depletion.

• Impact on Differentiation and Phenotype: The use of clone 53-5.8 has facilitated functional studies revealing intrinsic requirements for CD8+ T cell differentiation, such as CD103-dependent pathways, and enabled precise phenotyping in competitive and adoptive transfer experiments.

• Recommended Usage: Scientific and commercial sources recommend careful interpretation of experimental results given the antibody’s potency and specificity for functional CD8+ T cell removal.

• Comparison with Other Clones: Peer-reviewed literature underscores that clone 53-5.8 is more selective and effective for targeting the CD8β subunit compared to some other clones against CD8α, which can spare non-cytotoxic CD8+ subsets.

In summary, citations of clone 53-5.8 focus on its high efficiency and specificity for depleting CD8+ T cells, its protective role in immune-mediated tissue injury in infectious disease models, and its utility in mechanistic studies of CD8+ T cell biology and differentiation.

Dosing regimens for the anti-mouse CD8β antibody clone 53-5.8 vary considerably across different experimental models, with variations in dose amounts, timing, and frequency depending on the specific research application and tumor model being studied.

Dose Amounts

The most commonly used dose is 5 mg/kg, which appears across multiple tumor models and experimental contexts. However, lower doses have also been employed successfully. In cancer models studying anthracycline resistance, researchers used 20 μg per mouse intraperitoneally, administered weekly starting from day 0. This represents a substantially lower dose compared to the standard 5 mg/kg regimen, yet still achieved effective CD8+ T cell depletion.

Timing and Frequency

The timing of antibody administration relative to tumor implantation shows significant variation. In some protocols, treatment begins the day before tumor implantation, continues on the day of implantation, and then weekly thereafter. This pre-emptive approach ensures CD8+ T cell depletion is established before tumor cells are introduced.

Other studies initiate treatment at different timepoints post-implantation. The specific timing depends on when investigators want to assess CD8+ T cell involvement in tumor control. The 5 mg/kg dose is typically administered on the day before, the day of implantation, and weekly thereafter in CD8 depletion studies.

For maintaining depletion throughout experiments, twice weekly dosing for 2-3 weeks is common in tumor models, while some protocols use weekly injections for long-term studies.

Model-Specific Considerations

Different tumor models employ distinct protocols. In CT26 and MC38 colon carcinoma models, as well as B16-F10 melanoma models, the standard 5 mg/kg dose is used with intraperitoneal administration. The duration of treatment varies from 2 weeks in MC38 models to 3 weeks in CT26 models.

Clone 53-5.8 is particularly valued because it completely depletes CD8+ T cells without depleting CD8+ CD11c+ dendritic cells, making it more selective than some alternative anti-CD8α antibodies. This selectivity allows for more precise interpretation of experimental results when distinguishing T cell effects from dendritic cell contributions.