Project description:Inhibition of IFN-I signaling promotes the control of persistent virus infection, but the underlying mechanisms remain poorly understood. Here we report that genetic ablation of IFNAR1 specifically in NK cells led to elevated numbers of T follicular helper cells, germinal center B cells, and plasma cells, resulting in hastened virus clearance comparable to IFNAR1 blockade by an IFNAR1 neutralizing antibody. Antigen-specific B cells and antiviral antibodies were essential for the accelerated control of LCMV Cl13 infection following IFNAR1 blockade. IFNAR1 signaling in NK cells promoted NK cell maturation, function, and killing of antigenspecific CD4 and CD8 T cells. Therefore, Inhibition of IFN I signaling in NK cells enhances CD4 and CD8 T cell responses, elevates humoral immune response, and thereby facilitates the control of persistent virus infection.
Project description:To understand the effect of type-I IFN signaling directly on CD8+ T cells following an LCMV infection we compared the overall gene expression of WT and Ifnar1-/- T cells following an LCMV infection. WT and Ifnar1-/- P14 cells were sorted from infected mice (day 3) that were depleted of NK cells or left untreated. Each sample and condition (WT or IFNAR) was performed in triplicates
Project description:Type I interferons (IFNs) are a family of cytokines that play an important role in regulating immune responses to pathogens and tumors and are used therapeutically. All IFNs are considered to signal via the heterodimeric IFNAR1-IFNAR2 complex, yet some subtypes such as IFN? can exhibit distinct functional properties, although the molecular basis of this is unclear. Here we demonstrate IFN uniquely and specifically ligates to IFNAR1 in an IFNAR2-independent manner and provide the structural basis of the IFNAR1-IFN interaction. We show that the IFNAR1-IFN complex transduces signals to modulate the expression of a set of genes independently of IFNAR2. Moreover, we show the in vivo importance of the IFNAR1-IFN signaling axis in a murine model of LPS-induced septic shock. Thus, we provide a molecular basis for understanding specific functions of IFN?. Interferon b induced gene expression in peritoneal exudate cells was measured 3hr post intra-peritoneal injection of 10,000IU/ml of interferon beta or saline into wildtype and Ifnar2-/- mice. Three independant experiments were performed for each treatment in both genotypes using different mice for each sample.
Project description:Type I interferon (IFN-I) signals through two receptor subunits, IFNAR1 and IFNAR2, to regulate sterile and infectious immunity. IFNAR1 expression is tightly regulated to prevent autoimmunity although the mechanisms governing this are incompletely understood. We investigated the strategies used by two flaviviruses, tick-borne encephalitis virus and West Nile virus, to antagonize IFN-I signaling. Infection with these viruses resulted in depletion of IFNAR1 associated with the function of the viral IFN-I antagonist, NS5. NS5 function was dependent on its ability to associate with prolidase (PEPD), a cellular dipeptidase. PEPD was required for IFNAR1 maturation and accumulation, as well as gene induction following IFNAR1 stimulation. The relevance of PEPD to human biology was confirmed in fibroblasts derived from patients with genetic prolidase deficiency that expressed low IFNAR1 and exhibited reduced responses to IFNAR1. Thus, by understanding flavivirus IFN-I antagonism, PEPD is revealed as a central regulator of IFN-I responses in humans. RNA was isolated from replicates of 4 cultured dermal fibroblast lines derived from patients with genetic prolidase deficiency (PEPD), as well as from 4 cultured dermal fibroblast lines derived from normal healthy donors. These were run on Agilent microarrays to compare differences in gene expression observed in PEPD fibroblasts compared with normal fibroblasts.
Project description:The experimental data indicate that during a persistent infection, lymphocytic choriomeningitis virus (LCMV) may both directly or indirectly modulate the regulatory cellular processes and alter the cellular functions that are not critical for the survival, but are needed for the homeostasis in the organism. Two-dimensional differential in-gel electrophoresis (2D-DIGE) and MALDI-TOF MS/MS analyses were used to determine the cellular proteome response of HeLa cell line to persistent LCMV infection. Quantitative analysis revealed 24 differentially abundant proteins, half of which were up-regulated and the rest down-regulated. Functional categorization showed that LCMV-responsive proteins were mainly involved in metabolism, stress and defense responses. Among identified proteins, significant changes were found for peroxiredoxins, family of antioxidant enzymes. Decreased amount of these antioxidant proteins was accompanied with the elevation of ROS content in infected cells.
Project description:Type I interferons (IFNs) are a family of cytokines that play an important role in regulating immune responses to pathogens and tumors and are used therapeutically. All IFNs are considered to signal via the heterodimeric IFNAR1-IFNAR2 complex, yet some subtypes such as IFN? can exhibit distinct functional properties, although the molecular basis of this is unclear. Here we demonstrate IFN uniquely and specifically ligates to IFNAR1 in an IFNAR2-independent manner and provide the structural basis of the IFNAR1-IFN interaction. We show that the IFNAR1-IFN complex transduces signals to modulate the expression of a set of genes independently of IFNAR2. Moreover, we show the in vivo importance of the IFNAR1-IFN signaling axis in a murine model of LPS-induced septic shock. Thus, we provide a molecular basis for understanding specific functions of IFN?.
Project description:Type I interferon (IFN-I) signals through two receptor subunits, IFNAR1 and IFNAR2, to regulate sterile and infectious immunity. IFNAR1 expression is tightly regulated to prevent autoimmunity although the mechanisms governing this are incompletely understood. We investigated the strategies used by two flaviviruses, tick-borne encephalitis virus and West Nile virus, to antagonize IFN-I signaling. Infection with these viruses resulted in depletion of IFNAR1 associated with the function of the viral IFN-I antagonist, NS5. NS5 function was dependent on its ability to associate with prolidase (PEPD), a cellular dipeptidase. PEPD was required for IFNAR1 maturation and accumulation, as well as gene induction following IFNAR1 stimulation. The relevance of PEPD to human biology was confirmed in fibroblasts derived from patients with genetic prolidase deficiency that expressed low IFNAR1 and exhibited reduced responses to IFNAR1. Thus, by understanding flavivirus IFN-I antagonism, PEPD is revealed as a central regulator of IFN-I responses in humans.
Project description:is involved in the formation of immune signaling complexes. To date only limited and moreover 35 conflicting data exist regarding the role of ADAP in NK cells. To extend existing knowledge we 36 investigated ADAP-dependency of NK cells in the context of in vivo infection with the intracellular 37 pathogen Listeria monocytogenes (Lm). Ex vivo analysis of infection-primed NK cells revealed 38 impaired expression of IFN-γ and chemokines as well as impaired cytotoxic capacity in NK cells 39 lacking ADAP as indicated by reduced CD107a surface expression and inefficient perforin 40 production. However, ADAP-deficiency had no global effect on NK cell morphology or intracellular 41 distribution of CD107a-containing vesicles. Proteomic definition of ADAPko and wild type NK cells 42 did not uncover obvious differences in protein composition during the steady state and moreover, 43 similar early response patterns were induced in NK cells upon infection independent of the genotype. 44 In line with protein network analyses that suggested an altered migration phenotype in naïve 45 ADAPko NK cells, in vitro migration assays uncovered significantly reduced migration of both naïve 46 as well as infection-primed ADAPko NK cells compared to wild type NK cells. We propose that this 47 migration defect might account at least in part for the fact that during in vivo infection significantly 48 lower numbers of ADAPko NK cells accumulate in the spleen i.e. the site of infection. In conclusion, 49 we show here that during systemic Lm infection in mice ADAP is essential for efficient cytokine and 50 chemokine production, cytotoxic capacity and migration of NK cells.
Project description:Here we show that Zika virus infection induces memory like NK cells that express CD27. This subset shared transcriptional changes with memory CD8 T cells, stem cells and stem like T cells. These NK cells with memory and stemness features which we term NK memory stem cells (SCMNK) demonstrated greater antiviral potential. Transcriptional data of SCMNK and non-memory NK cells is presented.