Anti-Mouse CD28 [Clone 37.51] — Purified in vivo PLATINUM™ Functional Grade

In Vivo Use of Clone 37.51 in Mouse Studies

Clone 37.51 is a well-characterized Syrian hamster monoclonal antibody specifically targeting mouse CD28, the co-stimulatory receptor essential for optimal T-cell activation. Its primary roles in in vivo mouse studies include modulating immune responses through either CD28 activation or blockade, depending on the experimental context.

Key Applications

• T-Cell Activation: When administered in vivo, clone 37.51 can stimulate T-cell proliferation and enhance cytokine (e.g., IL-2) production, mimicking physiological CD28 co-stimulation. This is particularly useful for amplifying immune responses in tumor immunotherapy models or vaccine studies.
• Costimulation in Functional Assays: The antibody is frequently used to provide a second signal necessary for full T-cell activation when combined with agents that engage the T-cell receptor (e.g., anti-CD3). This is critical in studies focusing on T-cell biology, vaccination, and immunomodulation.
• Blockade of CD28 Signaling: Although less commonly, clone 37.51 has also been used to block CD28 interactions in vivo, potentially dampening immune responses for research into autoimmunity or transplantation tolerance.
• NK Cell Modulation: Since CD28 is also expressed on certain subsets of NK cells in mice, this clone can be used to study NK cell activation and function in vivo.

Technical Considerations

• Formulation: Special low-endotoxin formulations are available for in vivo use to minimize nonspecific immune activation or toxicity.
• Dosing and Administration: The optimal dose, route (intravenous, intraperitoneal, or other), and schedule depend on the specific experimental goals and should be determined empirically by each investigator.
• Controls: Appropriate isotype-matched controls (e.g., Syrian hamster IgG) are recommended to distinguish specific effects from nonspecific antibody-mediated effects.
• Validation: Clone 37.51 has been widely validated in both in vitro and in vivo contexts, ensuring reliable reproducibility in immunological studies.

Summary Table

Conclusion

Clone 37.51 is a versatile tool for in vivo mouse studies, primarily used to manipulate CD28-mediated co-stimulation of T cells but also applicable in NK cell research. Its effects—either activating or blocking—depend on experimental design, and its use requires careful optimization of dose, timing, and formulation for robust and interpretable results.

The correct storage temperature for sterile packaged clone 37.51 is 4°C.

Storage Requirements

The Anti-mouse CD28(37.51)-InVivo antibody should be stored at 4°C in the dark to avoid freeze-thaw cycles. This temperature requirement applies specifically to the undiluted solution from the date of receipt.

Additional Storage Considerations

The product datasheet indicates that this clone 37.51 antibody is formulated in PBS at pH 7.0 and contains no stabilizers or preservatives. It has a protein concentration of 3.84 mg/mL with 99% purity and an endotoxin level of less than 1 EU/mg.

It's worth noting that while products may sometimes be shipped at temperatures that differ from the recommended storage temperature, the manufacturer ensures that shipping conditions maintain reagent quality, and the long-term storage should follow the 4°C requirement specified on the product datasheet.

The 37.51 antibody specifically targets mouse CD28, a key T cell costimulatory receptor involved in immune activation. In the scientific literature, when 37.51 is used—to study T cell activation, costimulation, or immune modulation—it is frequently used in combination with other antibodies or proteins that target related T cell surface markers and signaling pathways.

Commonly used antibodies/proteins in conjunction with 37.51 include:

• Anti-CD3 (e.g., clone 145-2C11): CD3 is a component of the T cell receptor (TCR) complex. Co-stimulation with anti-CD3 and anti-CD28 (37.51) antibodies is a well-established method for robustly activating mouse T cells, as CD3 engagement provides the primary activation signal and CD28 delivers the costimulatory ("second") signal required for full activation and proliferation.
• CD80 (B7-1) and CD86 (B7-2) antibodies/ligands: Since CD28 binds these ligands on antigen-presenting cells, studies may include blocking or engaging CD80/CD86 to dissect costimulatory signaling along with 37.51.
• Other lineage or activation markers (examples):
  • CD4 or CD8: To distinguish and study subsets of T cells (helper or cytotoxic) and assess responses.
  • CD25 (IL-2R?): Used to measure T cell activation.
  • Intracellular cytokine stains (e.g., IL-2, IFN-?): To quantify functional responses after costimulation by CD3 and CD28.
• Isotype controls and fluorochrome-conjugated secondary antibodies: These help control for specificity and enable multiparametric analysis in flow cytometry.

Frequently, protocols for T cell activation, proliferation, and functional assays employ a combination of anti-CD3 (primary activation), anti-CD28 (37.51, costimulation), and additional surface or intracellular markers to characterize immune cell phenotypes and responses. This strategy is standard in both in vitro and in vivo murine immunology studies.

In summary, anti-CD3 antibodies are the most commonly co-used reagent with 37.51, but studies often expand to include markers of T cell subsets, activation status, and costimulatory/inhibitory ligands to comprehensively analyze immune cell function.

The key findings from scientific literature citing clone 37.51 focus on its role as an anti-mouse CD28 monoclonal antibody widely used to study T cell costimulation in immunological research. Clone 37.51 is primarily referenced in studies investigating T cell activation, proliferation, cytokine production, and the development of cytotoxic T lymphocytes (CTLs).

Main findings from citations include:

• Potent Costimulation: The 37.51 antibody is used to provide a costimulatory signal via CD28 during T cell activation, which is essential for optimal proliferation, cytokine release, and CTL development in vitro and in vivo.
• Expression Pattern: CD28, the target of clone 37.51, is expressed on nearly all CD4+ and CD8+ mouse T cells (most thymocytes and peripheral T cells) but at low levels on NK cells.
• Role in T and NK Cell Function: Several studies show clone 37.51 enhances the proliferative response and effector functions of T cells and, in some reports, murine NK cells via CD28 signaling.
• Mechanistic Studies: Citations encompass mechanistic research on CD28-mediated signaling pathways (such as studies on the MAPK pathway, sensitivity modulation, and signal integration via Akt) and how costimulation impacts effector and memory T cell differentiation.
• Functional Blockade: Some works examine how blocking CD28 with clone 37.51 can inhibit T cell activation or cytotoxic function, confirming a critical requirement for CD28 in these processes.
• Detailed Usage: Flow cytometry studies frequently use clone 37.51 to distinguish CD28+ T cell subsets and analyze receptor induction on immune cells post-activation.

Representative findings from specific studies:

• Augmentation of Proliferation and Cytokine Production: Clone 37.51 increases in vitro T cell proliferation, IL-2 secretion, and promotes CTL development.
• Costimulation in NK Cells: CD28-mediated costimulation, using 37.51, is necessary for optimal murine NK cell proliferation.
• Development Without Thymic Epithelium: 37.51 aids in defining the role of surface molecules in driving T cell development in the absence of the thymic epithelium.

Summary Table

In summary, clone 37.51 is a critical research tool for dissecting the role of CD28 in murine immune cell activation and function, with literature consistently showing its necessity for robust T and NK cell responses.