Technical Note: IL-17 Family Antibodies for Flow Cytometry

R&D Systems has added several new fluorochrome-conjugated antibodies for the Interleukin 17 (IL-17) family of ligands and receptors. IL-17 family ligands are pro-inflammatory cytokines that induce local cytokine production and are involved in the regulation of immune functions, most notably allergic responses. The six members, IL-17, IL-17B, IL-17C, IL-17D, IL-17E (also known as IL-25), and IL-17F are structurally related proteins with a conserved cysteine-knot fold near the C-terminus and considerable sequence divergence at the N-terminus. IL-17 family members activate three receptors, IL-17 R, IL-17B R, and IL-17 RC. Two orphan receptors exhibiting homology to IL-17 R, but whose functional ligands are not current­ly known, have been named IL-17 RD and IL-17 RE. Detection of intracellular staining by flow cytometry using new conjugated antibodies for IL-17B (Figure 1), IL-17C (Figure 2) or IL-17E (Figure 3) are shown below. IL-17B is highly expressed in the spinal cord and binds IL-17B R but not IL-17 R. IL-17B and C have been shown to stimulate the release of TNF-alpha and IL-1 beta from the human monocytic cell line THP-1. IL-17E binds and activates IL-17B R, which is upregulated under inflam­matory conditions. A complete listing of fluorochrome-conjugated antibodies for the IL-17 family of ligands and receptors offered by R&D Systems is shown in Table 1. In addition, R&D Systems offers a Human IL-17 Fluorokine® Flow Cytometry Kit (Catalog # NF1700) for the purpose of detecting functional receptors of IL-17 and for estimating their density on cell surfaces.

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Figure 1: Intracellular staining of K562 cells with PE-conjugated anti-human IL-17B monoclonal antibody (Catalog # IC1248P; filled histogram) or with mouse IgG2B isotype control antibody (Catalog # IC0041P; open histogram). Figure 2: Intracellular staining of PC-3 cells with PE-conjugated anti-human IL-17C monoclonal antibody (Catalog # IC1234P; filled histogram) or mouse IgG2B isotype control antibody (Catalog # IC003P open histogram). Figure 3: Intracellular staining of PC-3 cells with APC-conjugated anti-human IL-17E monoclonal antibody (Catalog # IC1258A; filled histogram) or with mouse IgG2B isotype control antibody (Catalog # IC002A; open histogram).