Anti-ICOS/CD278 Rabbit Polyclonal Antibody for WB, IF/ICC, ELISA - Q9Y6W8

Core Product Specifications and Parameters

Biological Background: ICOS/CD278 Function and Localization

• ICOS (Inducible T-cell costimulator), also known as AILIM and CD278, is a stimulatory receptor expressed on activated T-cells. It belongs to the CD28 family of immune costimulatory molecules and contains an immunoglobulin domain.
• ICOS plays a crucial role in T-cell responses by binding to its ligand ICOSL on APCs, delivering costimulatory signals that enhance T-cell proliferation, cytokine secretion (e.g., IL10), and help for B-cell antibody secretion. Related references: PMID:9930702, PMID:33033255
• It is critical for the differentiation of T follicular regulatory cells during immune challenges like viral infection, acting via PI3K signaling and TCR-induced calcium flux modulation. Related references: PMID:27135603, PMID:30523347
• ICOS prevents apoptosis of pre-activated T-cells and is essential for efficient T-B cell interactions and CD40-mediated class switching of immunoglobulin isotypes.
• Subcellularly, ICOS is localized to the cell membrane and can also be secreted.
• It is highly expressed on tonsillar T-cells in germinal centers, with lower levels in thymus, lung, lymph node, and peripheral blood leukocytes, showing a tissue-specific expression pattern.
• Post-translational modifications include glycosylation and disulfide bond formation, contributing to its structural stability.
• Alternative splicing may generate multiple isoforms, adding functional diversity.

Experimental Guidance and Technical Tips

• The immunogen corresponds to the extracellular domain (aa 21-140) of human ICOS, which shares high homology with mouse and rat, supporting cross-reactivity.
• For Western blot, a band around 23 kDa (sometimes appearing as a doublet due to glycosylation) is expected; consider using positive control lysates from activated T-cells.
• In immunofluorescence/ICC, permeabilization may be required for intracellular detection; validate staining in T-cell lines such as Jurkat.
• For ELISA, the antibody may be used as a capture or detection antibody; consider pairing with other ICOS antibodies or ICOSL-Fc fusion proteins.
• Always include appropriate negative controls (e.g., ICOS-deficient cells or blocking peptide) to confirm specificity.
• Consider testing a range of dilutions starting from 1:500 for WB and 1:50 for IF, as polyclonal antibodies can vary between lots.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio is a trusted one-stop partner for IVD raw materials, providing diagnostic manufacturers and research labs with comprehensive access to high-quality antibodies, antigens, and ancillary reagents. Our portfolio includes validated polyclonal and monoclonal antibodies, such as this anti-ICOS/CD278 antibody, which is ideal for immunological research into T-cell activation and checkpoint regulation. We support bulk orders, custom sourcing for rare targets, and technical consulting to accelerate your assay development from concept to clinic.