Interferon-? reduces Ia4 dendritic cell traffic to the lung

Abstract: MHC class II ’ lung dendritic cells (DC) increase in number following treatment of animals with interferon-y (IFN-y) [Kradin et a!. (1991) Am. J, Resp. Mol. Biol. 4,210; Gonget al. (1992)J. Exp. Med. 175, 797]. To test whether this is due to increased sequestration and/or trafficking of DC to the lung, bone marrow DC from BALB/c mice were obtained by culturing bone marrow with granulo-cyte-macrophage colony-stimulating factor (GM-CSF). Recipient BALB/c mice were injected intraperitoneally (i.p.) for 4 days with one of the following: IFN-’y, dexamethasone (Dex), or phos-phate-buffered saline (PBS). Twenty-four hours af-ter the last dose, they were injected intravenously (i.v.) with carboxyfluorescein (Fl)-labeled DC (1