Anti-Mouse CD278 (ICOS) (Clone 7E.17G9) – Purified in vivo PLATINUM™ Functional Grade

Clone 7E.17G9 is a rat anti-mouse monoclonal antibody that targets ICOS (Inducible T-cell Co-Stimulator, also known as CD278) and has several important applications in mouse research models, particularly for studying immune responses and T-cell biology.

Primary In Vivo Function

The antibody is widely used as a blocking agent to inhibit the interaction between ICOS and its ligand ICOSL (also called B7h/B7RP-1 or B7-H2), thereby modulating T-cell activation and immune responses. This blocking capacity has been specifically demonstrated in functional assays where 7E.17G9 prevents ICOSL from binding to ICOS.

Key Research Applications

Immune Response Modulation: By blocking ICOS-ICOSL interactions, researchers can investigate the role of this costimulatory pathway in various immune processes. ICOS signaling is crucial for T-cell activation and proliferation, and the antibody allows scientists to study what happens when this pathway is inhibited.

B Cell and Humoral Immunity Studies: Since ICOS has been shown to be involved in humoral immune responses and B cell germinal center formation, the blocking antibody is valuable for studying antibody production and B cell-dependent immune responses.

Regulatory T Cell Research: ICOS signaling is thought to be important for maintaining regulatory T cell homeostasis, making 7E.17G9 useful for investigating Treg function and stability in various disease models.

Th2 Cell Development: The antibody can be used to study the role of ICOS in Th2 cell differentiation, as ICOS stimulation has been shown to potentiate TCR-mediated IL-4 and IL-10 production.

Inflammatory Disease Models: Given that ICOS has been proposed to play a protective role in inflammatory autoimmune diseases and is involved in airway tolerance and downregulation of pulmonary inflammation, 7E.17G9 serves as a tool for investigating these pathological conditions.

The antibody is specifically manufactured for in vivo use with appropriate quality specifications, including low endotoxin levels (less than 0.001 ng/µg), high purity (greater than 90%), and minimal aggregation (less than 10%).

When analyzing the 7E.17G9 antibody, which targets mouse ICOS (Inducible COStimulatory molecule), other commonly used antibodies or proteins in the literature include:

• CD28 and CTLA-4 antibodies: These proteins are homologous to ICOS and are critical costimulatory molecules in T cell activation studies, often analyzed in parallel to profile costimulatory signaling.

• Isotype controls: Such as Rat IgG2b isotype controls, are often used as negative controls in flow cytometry experiments to ensure the specificity of the staining.

• Other antibodies targeting T cell surface molecules: These can include antibodies against CD3, CD4, CD8, and PD-1, which are used to study T cell subsets and their activation states in combination with ICOS.

• B7h/B7RP-1 and B7-H2: These are ligands for ICOS and can be involved in studies examining the interaction between ICOS and its ligands in immune responses.

These antibodies and proteins are used to understand the role of ICOS in T cell activation and immune responses, comparing it with other costimulatory pathways.

The clone 7E.17G9, associated with the anti-CD278 (ICOS) monoclonal antibody, is widely used in scientific research for detecting and analyzing ICOS expression. Here are the key findings from its citations in scientific literature:

1. ICOS Expression and Function: ICOS is a costimulatory molecule expressed on activated T cells, playing a crucial role in T cell activation and proliferation. It is involved in the development of Th2 cells and is required for humoral immune responses.

2. Antibody Properties and Applications: The 7E.17G9 antibody has been primarily used in flow cytometric analysis to detect ICOS expression on mouse T cells. It is noted for its ability to stain stimulated mouse splenocytes effectively.

3. Signaling and Agonistic Activity: Despite being reported as a blocking antibody, 7E.17G9 has shown agonistic properties in some studies, enhancing AKT phosphorylation in activated T cells. This suggests that it may have non-trivial effects on ICOS signaling pathways.

4. Imaging and Diagnostic Applications: ICOS targeting has been explored in imaging studies, such as immunoPET, to visualize activated T cells in models of graft-versus-host disease (GvHD). This technique allows for early diagnosis and monitoring of inflammatory conditions.

5. In Vivo Studies: Clone 7E.17G9 is used in in vivo mouse studies to inhibit ICOS interactions, which helps understand its role in immune responses and potential therapeutic interventions.

The dosing regimen of the clone 7E.17G9 monoclonal antibody to mouse ICOS can vary across different mouse models. While specific dosages might differ, a common approach is intraperitoneal (i.p.) injection. Here are some general trends observed in different studies:

• General Dosing: A typical dose for intraperitoneal administration is 100 µg/mouse. This has been used in various studies to block ICOS function in vivo.

• Frequency and Interval: Dosing intervals can vary based on the experimental design. For example, in one study, the antibody was administered 2 days post-irradiation (IR) and then on days 6 and 9 post-IR. Other regimens might involve repetitive dosing over a period that suits the model's needs.

• Dose Titration: Some studies have explored dose titration, using a range of doses (1, 5, 20, 100, and 200 mg per mouse) to assess efficacy and safety in combination with other treatments.

The choice of dosing regimen can depend on the specific tumor model, the desired effect on immune responses, and the combination with other therapies like radiation or checkpoint inhibitors.