Type I interferon regulates pDC maturation and Ly49Q expression

Abstract

Ly49Q is expressed on peripheral mouse plasmacytoid dendritic cells (pDC). Immature Ly49Q-negative pDC precursors acquire Ly49Q in the bone marrow and then migrate into the periphery. While searching for molecules that regulate pDC maturation, we found that type I interferon (IFN) inhibited Ly49Q acquisition in vitro. Infections that induce type I IFN production by cells other than pDC (a condition mimicked by poly(I:C) injection in vivo) increase the prevalence of Ly49Q- pDC in the bone marrow and peripheral lymphoid organs in wild-type but not IFN-α/β receptor knockout BALB/c mice. Moreover, in vivo exposure to type I IFN causes some Ly49Q-, but not Ly49Q+, pDC to convert to conventional DC, defined as B220- CD11c+ CD11b+ cells. These data suggest that type I IFN regulates pDC development and affects their distribution in the body. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.