Human DCs express endothelin receptors upon maturation. Immunohistochemical expression of ETA and ETB receptors by immature human dendritic cells (DC), and by DCs stimulated with S aureus (DC + SA). DCs were collected on the seventh day of the culture, either immature or after 48-hour stimulation, and cytospun to the slides. Immunostaining was performed using antibodies against ETA and ETB receptors and the Vectastatin ABC system. Negative controls included staining with irrelevant isotype-matched antibodies. The results from a representative experiment (of 3) are shown. (A) Immature DCs stained with anti-ETA receptor antibodies. (B) Mature DCs (DC + SA) stained with anti-ETA receptor antibodies. (C) Immature DCs stained with anti-ETB receptor antibodies. (D) Mature DCs (DC + SA) stained with anti-ETB receptor antibodies. (E) Negative control: immature DCs stained with isotype-matched irrelevant antibodies. (F) Negative control: mature DCs (DC + SA) stained with isotype-matched irrelevant antibodies. Color was developed with a DAB reagent kit (Biogenex, San Ramon, CA) and slides were counterstained. Microscopy was performed using a Zeiss Axioplan 2 microscope (Carl Zeiss Microimaging, Thornwood, NY) equipped with a digital camera and a 20 ×/0.5 objective (A-D) or a 10 ×/0.5 objective (E,F). Images were acquired using AxioVision KS300 software (Carl Zeiss Microimaging).
