Two novel genes FIND and LIND differentially expressed in deactivated and Listeria-infected human macrophages

Deactivation of macrophage functions plays an important rule in human infec tious and inflammatory diseases. In this study, differential-display RT-PCR was used to analyze the gene expression of human mononuclear phagocytes de activated with interleukin (IL)-4, IL-10, and dexamethasone (DEX), in the a bsence and presence of infection with Listeria monocytogenes (Listeria). Tw o novel differentially expressed mRNA species were discovered: FIND (IL-Fou r INDuced) was upregulated with IL-4 but downregulated with DEX, and is pre dicted to code for an M-r 53,000 transmembrane protein. LIND (Listeria INDu ced) was induced by Listeria infection, and is predicted to code for an M-r 39,000 nuclear or cytoplasmic protein containing three coiled-coil domains . In addition, we report several novel effects of deactivators and infectio n on the expression of known genes: (1) IL-C caused pronounced upregulation of ABCG2, coding for an ATP-binding cassette transporter highly expressed in the placenta, which mediates multidrug, resistance of cancer cells, but is otherwise of unknown function; (2) both DEX and IL-4 downregulated osteo pontin, an important factor of host resistance against intracellular infect ions; (3) inhibition of the CC-chemokine I-309 mRNA expression by all three deactivators in the presence of Listeria infection, and (3) upregulation b y Lister-in infection of the interferon-stimulated gene ISG20 of unknown fu nction, whose product localizes with nuclear dots/ PML bodies.