Anti-Human PPP2CA (a.a. 1-309) Polyclonal antibody

Upon immune recognition of viruses, the mammalian innate immune response activates a complex signal transduction network to combat infection. This activation requires phosphorylation of key transcription factors regulating IFN production and signaling, including IFN regulatory factor 3 (IRF3) and STAT1. The mechanisms regulating these STAT1 and IRF3 phosphorylation events remain unclear. Here, using human and mouse cell lines along with gene microarrays, quantitative RT-PCR, viral infection and plaque assays, and reporter gene assays, we demonstrate that a microRNA cluster conserved among bilaterian animals, encoding miR-96, miR-182, and miR-183, regulates IFN signaling. In particular, we observed that the miR-183 cluster promotes IFN production and signaling, mediated by enhancing IRF3 and STAT1 phosphorylation. We also found that the miR-183 cluster activates the IFN pathway and inhibits vesicular stomatitis virus infection by directly targeting several negative regulators of IRF3 and STAT1 activities, including protein phosphatase 2A (PPP2CA) and tripartite motif?containing 27 (TRIM27). Overall, our work reveals an important role of the evolutionarily conserved miR-183 cluster in the regulation of mammalian innate immunity.

Cross-Reacting Material 197 (CRM197) is a diphtheria toxin non-toxic mutant that has shown antitumor activity in mice and humans. It is still unclear whether this anti-tumorigenic effect depends on its strong inflammatory-immunological property, its ability to inhibit heparin-binding epidermal growth factor (HB-EGF), or even its possible weak toxicity. CRM197 is utilized as a specific inhibitor of HB-ECF that competes for the epidermal growth factor receptor (EGFR), overexpressed in colorectal cancer and implicated in its progression. In this study we evaluate the effects of CRM197 on HT-29 human colon cancer cell line behaviour and, for CRM197 recognized ability to inhibit HB-EGF, its possible influence on EGFR activation. In particular, while HT-29 does not show any reduction of viability after CRM197 treatment (MTT modified assay), or changes in cell cycle distribution (flow cytometry), in EGFR localization, phospho-EGFR detected signals (immunohistochemistry) or in morphology (scanning electron microscopy, SEM) they show a change in the gene expression profile by microarray analysis (cDNA microarray SS-H19k8). The overexpression of genes like protein phosphatase 2, catalytic subunit, alpha isozyme (PPP2CA), guanine nucleotide-binding protein G subunit alpha-1(GNAI1) and butyrophilin, subfamily 2, member A1 (BTN2A1) has been confirmed with real-time-qPCR. This is the first study where the CRM197 treatment on HT-29 shows a possible scarce implication of endogenous HB-EGF on EGFR expression and cancer cell development. At the same time, our results show the alteration of a specific and selected number of genes.