Background Swiprosin-1 was identified in human CD8+ lymphocytes mature B cells and non-lymphonoid tissue. attrs :”text”:”A23187″ term_id :”833253″ term_text :”A23187″}A23187-induced NF-κB promoter activity and cytokine expression including IL-3 and IL-8 (3). However the mechanism how swiprosin-1 involves in the cytokine production in mast cells is not investigated. In other cell types the only reported functions are that swiprosin-1 is associated with lipid rafts in the immature B-cell line WEHI231 and that it participates in GW4064 enhancement of BCR signals and contributes to BCR-induced apoptosis (2 4 Mast cells are broadly distributed throughout mammalian tissues and play a critical role in a variety of biological responses (5-7). Typically mast cells are considered in association with immediate-type hypersensitivity (5). However several recent reports have provided evidence for the possible participation of mast cells in more persistent and even in chronic inflammatory and immunological responses (8 9 Of note a variety Rabbit Polyclonal to EFNA2. of cytokines including IL-3 IL-4 IL-5 IL-6 IL-8 TNF-α and IFN-γ (10-12) are produced in mast cells and play an important role in immunological processes other than IgE-mediated hypersensitivity reactions. Given the potential GW4064 importance of mast cell-derived cytokines in physiological or pathological immune reactions it is essential to understand the signaling pathways and molecules involved in cytokine regulation in mast cells. Until recently however only a limited number of reports have examined the regulatory mechanism of cytokine expression in mast cells while the mechanism of mast GW4064 cell degranulation mediated by the high affinity IgE receptor (FcεR1) is relatively well characterized (7). As part of genome-wide approaches to finding novel genes that may be involved in mast cell activation we have previously found that swiprosin-1 is over-induced in the human mast cell line HMC-1 stimulated with PMA/{“type”:”entrez-nucleotide” attrs :{“text”:”A23187″ term_id :”833253″ term_text :”A23187″}}A23187 (3). In the present study we examined using confocal microscopy the three-dimensional localization of swiprosin-1 in various cell lines including HMC-1 cells 293 cells and COS-7 cells. {We then asked whether swiprosin-1 potentially modulates mast cell activation and cytokine expression in relation to its localization.|We then asked whether swiprosin-1 potentially modulates mast cell cytokine and activation expression in relation to its localization.} Database mining revealed that swiprosin-1 putatively contains four myristylation sites three binding sites for SH3 domain containing proteins two potential EF-hand domains and a coiled-coil domain at the C-terminus and therefore may have a role as a small adaptor protein involved in calcium signaling (1). In accordance with this prediction swiprosin- 1 was implicated in phosphotyrosine-based signaling events involved in the cellular stimulation of early growth factor (EGF)3 and in actin rearrangement (13). By utilizing HMC-1 cell line which was established from a patient with mast cell leukemia we studied whether swiprosin-1 involves in the expression of human cytokines and chemokines. The results presented here strongly demonstrate that swiprosin-1 potentially acts as a regulator for cytokine expression and activation of mast cells. MATERIALS AND METHODS Antibodies and reagents Goat polyclonal antibody to swiprosin-1 was from Imgenex (San Diego CA). Antibodies to p-PI3K p-Akt and GFP were from Cell Signaling Technology Inc (Beverly MA). HRP-conjugated anti-goat anti-rabbit and anti-mouse IgGs were from GE Healthcare (Chalfont St. Giles United GW4064 Kingdom). SB-203580 PD98059 MG132 cyclosporine A and PP2 were purchased from Calbiochem-Behring (La Jolla CA). Total RNA isolation reagent was from WelPrep? Join Bio Innovation (Daegu South Korea). Maxime RT Premix (oligo dT primer) Maxime PCR PreMix and a plasmid purification kit were from iNtRON Biotechnology (Daejon South Korea). SYBR premix Ex Taq was from Takara Bio Inc (Shiga Japan). The dual-luciferase reporter assay system was from Promega Corporation (Madison WI). The ELISA kit for hIL-8 was from R&D Systems (Minneapolis MN). All other reagents used in this study were purchased from Sigma Chemical Co (St. Louis MO). Cell culture HMC-1 cells were cultured in IMDM medium. Jurkat T and Molt-4 T cells (T cells) Raji B cells (B cells) THP-1 cells (monocytes) and 293-T and CHO-K1 cells (epithelial cells) were.