Detection of IL-17RA protein on the cell surface of neonatal glial cells. Purified astrocytes (A) and microglia (B) cultured on chamber slides were fluorescently labeled with anti-IL-17RA antibody and CY2 -conjugated Hamster anti-goat IgG secondary antibody. The majority of astrocytes showed punctuate surface staining (A), whereas IL-17RA staining was much weaker in microglia (B). Binding of polyclonal-anti-mouse IL-17R-fluorescein on the surface of isolated astrocytes and microglia was tested using flow cytometric analysis. Cells were double labeled with anti-GFAP (intracellular marker for astrocytes) and IL-17RA antibody (C) or anti-CD11b (for microglia) and IL-17RA antibody (D). Protein G- coupled normal goat-IgG conjugated with carboxyfluorescein was used as isotype. Cells were gated either for GFAP or for CD11b, and IL-17RA expression on gated cells shown in single parameter FACS plot against the isotype staining demonstrates a prominent population of IL-17RA positive astrocytes, but only rare positive microglia.