Introduction Astrocytes are the most abundant glial cell type. in C57BL/6 mice TNFSF11 astroglial cells in response to lipopolysaccharide (LPS) using reverse-transcription polymerase BMS-911543 BMS-911543 chain reaction (RT-PCR) method. Results We provide for the first time evidence that astrocytes can express IL-19 mRNA following LPS stimulation. Furthermore we have found the expression of IL-19 mRNA in the cortex of adult C57BL/6 mice following intraperitoneal (i.p.) administration of LPS. Discussion This finding will contribute to current knowledge on the function and behavior of cells and mediators during inflammatory conditions in BMS-911543 the brain. Keywords: IL-19 Mice Astroglial Cells brain Cortex Lipopolysaccharide 1 Introduction Glial cells play an important role in controlling of CNS inflammation. Astrocytes are the most abundant glial cell type in the brain (Kim Hong & BMS-911543 Ro 2011 BMS-911543 Astrocytes are multifunctional glial cells that regulate extracellular ion and neurotransmitter concentrations and are also involved in the immune responses. Astrocytes produce neurotrophic and neuroprotective factors and participate in the CNS repair procedure (Minagar et al. 2002 When inflammation occurs in the brain astrocytes are activated and involved in the process of reactive gliosis and the formation of a glial scar (Ledeboer et al. 2002 Astrocytes take part in immune functions by expression of adhesion molecules chemokines and production of proinflammatory mediators such as IL-1 IL-6 and tumor necrosis factor-α (TNF-α) in response to a variety of stimuli (Dong & Benveniste 2001 Astrocytes may participate in the downregulation of T cell autoreactivity in the CNS. Indeed astrocytes BMS-911543 can suppress microglial IL-12 production which is crucial for Th1 differentiation. In addition Astrocytes produce several immunosuppressive molecules for example prostaglandin E2 (PGE2) or transforming growth factor-β (TGF-β) (Aloisi Ria & Adorini 2000 Astrocytes represent the non-professional class of CNS-resident antigen presenting cells (APCs) (Constantinescu et al. 2005 These cells can not constitutively express MHC class II molecules; however MHC class II expression can be induced with Interferon (IFN)-γ and further modulated by TNF-α (Dong & Benveniste 2001 In vitro activated astrocytes can stimulate autoreactive T cells and it has been suggested that astrocytes may promote CNS inflammation (Kort et al. 2006 The IL-10 family of cytokines has different biological functions and includes IL-10 IL-19 IL-20 IL-22 IL-24 IL-26 IL-28A IL-28B and IL-29 (Sabat et al. 2007 Sabat et al. 2010 Zdanov 2010 Data have shown that IL-19 IL-20 IL-22 IL-24 and IL-26 have structural homology and constitute the IL-20 subfamily In fact IL-10 is an immunosuppressive cytokine but and it seems likely that these cytokines belonging to IL-20 subfamily are proinflammatory (Sa et al. 2007 IL-10 IL-19 IL-20 and IL-24 are primarily secreted by activated macrophages whereas T cells are the main source of IL-22 IL-26 and IL-28 (Wolk et al. 2010 Gallagher et al. 2000 The IL-10 family of cytokine binds to heterodimeric transmembrane receptor complexes that are composed of a long α-chain (R1-type; with a long cytoplasmic domain) and a shorter β-chain (R2-type; with a short cytoplasmic domain) (Blumberg et al. 2001 IL-19 has 21% shared amino acid similarity with IL-10. Previous findings indicated that IL-19 is primarily produced by monocytes and LPS IL-4 and granulocyte monocyte-colony stimulating factor (GM-CSF) can induce its expression (Blumberg et al. 2001 Gallagher et al. 2000 Furthermore keratinocytes and bronchial epithelia have also been reported to express IL-19 in vitro under stimulatory conditions (Sa et al. 2007 IL-19 signaling occurs through a receptor complex composed of the IL-20R1 and IL-20R2 chains and activates monocytes in an autocrine and paracrine fashion (Blumberg et al. 2001 Concerning the biological effects of IL-19 controversial data exist. Several investigators have demonstrated that long time exposure of T cells to IL-19 plays a role in the appearance of increased numbers of IL-4 and IL-13 producing and fewer IFN-γ producing cells; therefore they have implicated IL-19 in Th2 immune differentiation. In addition IL-19 increased IL-10 production in peripheral blood mononuclear cells (PBMCs) (Leng et al. 2011 Jordan et al. 2005 Oral et al. 2006 These observations suggest that IL-19 may have.