Recent Submissions

  • Redispersible Spray-Dried Powder Containing Nanoencapsulated Curcumin: the Drying Process Does Not Affect Neuroprotection In vitro.

    de Andrade, Diego Fontana; Vukosavljevic, Branko; Hoppe, Juliana Bender; Pohlmann, Adriana Raffin; Guterres, Sílvia Stanisçuaski; Windbergs, Maike; Külkamp-Guerreiro, Irene; Salbego, Christianne Gazzana; Beck, Ruy Carlos Ruver; HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.;TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Springer, 2019-08-12)
    A redispersible spray-dried formulation containing curcumin-loaded, lipid-core nanocapsules (LNC-C) was developed for oral administration. The neuroprotective activity of curcumin after the spray-drying process was evaluated in vitro. The spray-dried powder (SD-LNC-C) was produced using a drying adjuvant composed of a blend of maltodextrin and L-leucine (90:10 w/w). Acceptable process yield (~ 70%) and drug content (6.5 ± 0.2 mg g-1) were obtained. SD-LNC-C was formed by smooth, spherical-shaped particles, and confocal Raman analysis indicated the distribution of the LNC-C on the surface of the leucine/maltodextrin agglomerates. The surface of the agglomerates was formed by a combination of LNC-C and adjuvants, and laser diffraction showed that SD-LNC-C had adequate aqueous redispersion, with no loss of controlled drug release behaviour of LNC-C. The in vitro curcumin activity against the lipopolysaccharide (LPS)-induced proinflammatory response in organotypic hippocampal slice cultures was evaluated. Both formulations (LNC-C and SD-LNC-C) reduced TNF-α to similar levels. Therefore, neuroprotection of curcumin in vitro may be improved by nanoencapsulation followed by spray-drying, with no loss of this superior performance. Hence, the redispersible spray-dried powder proposed here represents a suitable approach for the development of innovative nanomedicines containing curcumin for the prevention/treatment of neurodegenerative diseases.
  • Generation of two human ISG15 knockout iPSC clones using CRISPR/Cas9 editing.

    Merkert, S; Jaboreck, M-C; Engels, L; Malik, M N H; Göhring, G; Pessler, F; Martin, U; Olmer, R; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Elsevier, 2020-12-22)
    Background and aims: T cells are the main mediators of allogeneic immune responses. Specific T cell clones can be tracked by their unique T cell receptor (TCR), but specificity and function remain elusive and have not been investigated in human liver biopsies thus far. Methods: TCR repertoire analysis of CD4+, CD8+ and regulatory T cells of the peripheral blood and liver graft was performed in seven liver transplant recipients with either stable course (non-rejector, NR), subclinical cellular rejection (SCR) or acute cellular rejection (ACR) during an observation period from pre-transplant to six years post-transplant. Furthermore, donor-reactive T cells, identified by their expression of CD154 and GARP after allogeneic activation, were tracked longitudinally in peripheral blood and within the liver allograft. Results: While overall clonality of the TCR repertoire did not increase in peripheral blood after liver transplantation, clonality of donor-reactive CD4+ and regulatory T cells increased and these clones accumulated within the liver graft. Surprisingly, the TCR repertoires between the liver graft and the periphery were distinct and showed only little overlap. Notably, during ACR TCR repertoires aligned suggesting either graft-specific homing or release of activated T cells from the graft. Conclusions: This is the first study comparing TCR repertoires between liver graft and blood in patients with NR, SCR and ACR. Moreover, we attribute specificity and function to a subgroup of intragraft T cell populations. Given the little overlap between peripheral blood and intragraft repertoires future studies investigating function and specificities of T cells after liver transplantation should focus on the intragraft immune response. For this purpose, protocol biopsies of patients with normal graft function and subclinical rejection have to be taken into account.
  • Targeted metabolomic profiling of cerebrospinal fluid from patients with progressive multifocal leukoencephalopathy.

    Luo, Yi; Möhn, Nora; Al-Mekhlafi, Amani; Schuchardt, Sven; Skripuletz, Thomas; Sühs, Wolfram; Pessler, Frank; Stangel, Martin; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (PLOS, 2020-11-24)
    Progressive multifocal leukoencephalopathy (PML), caused by JC polyomavirus, is a demyelinating disease of the central nervous system that primarily affects oligodendrocytes. It can cause significant morbidity and mortality. An early diagnosis is of high relevance as timely immune reconstitution is essential. However, diagnosis can be challenging if virus detection via cerebrospinal fluid (CSF) PCR remains negative. Hence, identifying CSF biomarkers for this disease is of crucial importance. We applied a targeted metabolomic screen to CSF from 23 PML patients and eight normal pressure hydrocephalus (NPH) patients as controls. Out of 188 potentially detectable metabolites, 48 (13 amino acids, 4 biogenic amines, 1 acylcarnitine, 21 phosphatidylcholines, 8 sphingolipids, and the sum of hexoses) passed the quality screen and were included in the analyses. Even though there was a tendency towards lower concentrations in PML (mostly of phosphatidylcholines and sphingomyelins), none of the differences between PML and controls in individual metabolite concentrations reached statistical significance (lowest p = 0.104) and there were no potential diagnostic biomarkers (highest area under the ROC curve 0.68). Thus, CSF metabolite changes in PML are likely subtle and possibly larger group sizes and broader metabolite screens are needed to identify potential CSF metabolite biomarkers for PML.
  • Triple RNA-Seq Reveals Synergy in a Human Virus-Fungus Co-infection Model.

    Seelbinder, Bastian; Wallstabe, Julia; Marischen, Lothar; Weiss, Esther; Wurster, Sebastian; Page, Lukas; Löffler, Claudia; Bussemer, Lydia; Schmitt, Anna-Lena; Wolf, Thomas; et al. (Elsevier (Cell Press), 2020-11-17)
    High-throughput RNA sequencing (RNA-seq) is routinely applied to study diverse biological processes; however, when performed separately on interacting organisms, systemic noise intrinsic to RNA extraction, library preparation, and sequencing hampers the identification of cross-species interaction nodes. Here, we develop triple RNA-seq to simultaneously detect transcriptomes of monocyte-derived dendritic cells (moDCs) infected with the frequently co-occurring pulmonary pathogens Aspergillus fumigatus and human cytomegalovirus (CMV). Comparing expression patterns after co-infection with those after single infections, our data reveal synergistic effects and mutual interferences between host responses to the two pathogens. For example, CMV attenuates the fungus-mediated activation of pro-inflammatory cytokines through NF-κB (nuclear factor κB) and NFAT (nuclear factor of activated T cells) cascades, while A. fumigatus impairs viral clearance by counteracting viral nucleic acid-induced activation of type I interferon signaling. Together, the analytical power of triple RNA-seq proposes molecular hubs in the differential moDC response to fungal/viral single infection or co-infection that contribute to our understanding of the etiology and, potentially, clearance of post-transplant infections.
  • Mice defective in interferon signaling help distinguish between primary and secondary pathological pathways in a mouse model of neuronal forms of Gaucher disease.

    Vardi, Ayelet; Ben-Dor, Shifra; Cho, Soo Min; Kalinke, Ulrich; Spanier, Julia; Futerman, Anthony H; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (BMC, 2020-09-07)
    Epstein-Barr virus (EBV) is a latent and oncogenic human herpesvirus. Lytic viral protein expression plays an important role in EBV-associated malignancies. The EBV envelope glycoprotein 350 (gp350) is expressed abundantly during EBV lytic reactivation and sporadically on the surface of latently infected cells. Here we tested T cells expressing gp350-specific chimeric antigen receptors (CARs) containing scFvs derived from two novel gp350-binding, highly neutralizing monoclonal antibodies. The scFvs were fused to CD28/CD3ζ signaling domains in a retroviral vector. The produced gp350CAR-T cells specifically recognized and killed gp350+ 293T cells in vitro. The best-performing 7A1-gp350CAR-T cells were cytotoxic against the EBV+ B95-8 cell line, showing selectivity against gp350+ cells. Fully humanized Nod.Rag.Gamma mice transplanted with cord blood CD34+ cells and infected with the EBV/M81/fLuc lytic strain were monitored dynamically for viral spread. Infected mice recapitulated EBV-induced lymphoproliferation, tumor development, and systemic inflammation. We tested adoptive transfer of autologous CD8+gp350CAR-T cells administered protectively or therapeutically. After gp350CAR-T cell therapy, 75% of mice controlled or reduced EBV spread and showed lower frequencies of EBER+ B cell malignant lymphoproliferation, lack of tumor development, and reduced inflammation. In summary, CD8+gp350CAR-T cells showed proof-of-concept preclinical efficacy against impending EBV+ lymphoproliferation and lymphomagenesis.
  • Impact of Physical Exercise on Gut Microbiome, Inflammation, and the Pathobiology of Metabolic Disorders.

    Sohail, Muhammad U; Yassine, Hadi M; Sohail, Aaqib; Al Thani, Asmaa A; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Society for Biomedical Diabetes Research, 2019-08-04)
    Background: The gastrointestinal tract (GIT) harbors a complex and diverse microbial composition that outnumbers our own body cells and their gene contents. These microbes play a significant role in host metabolism and energy homeostasis. Emerging evidence suggests that the GIT microbiome significantly contributes to host health and that impairments in the microbiome may cause the development of metabolic diseases. The microbiome architecture is shaped by several genetic and environmental factors, including nutrition and physical activity. Physical exercise has preventive or therapeutic effects in respiratory, cardiovascular, neuroendocrine, and muscular diseases. Yet, we still have little information of the beneficial effects of physical exercise on GIT health and microbial composition. Furthermore, we are not aware whether exercise-derived benefits on microbiome diversity can beneficially influence other tissues and body organs. Objectives: The aim of this article is to review the available literature on exercise-induced microbiome changes and to explain how these changes may induce inflammatory, immune, and oxidative responses that may contribute to the improvement of metabolic disorders. Methods: A systemic and comprehensive search of the relevant literature using MEDLINE and Google Scholar databases was conducted during fall 2018 and spring 2019. The search identified sixty-two research and review articles that discussed exercise-induced microbiome changes. Results: The review of the relevant literature suggests that exercise-induced microbial changes affect the host's immune pathways and improve energy homeostasis. Microbes release certain neuroendocrine and immune-modulatory factors that may lower inflammatory and oxidative stress and relieve patients suffering from metabolic disorders. Conclusions: Exercise-induced changes in microbial diversity are able to improve tissue metabolism, cardiorespiratory fitness, and insulin resistance.
  • Type I Interferon Receptor Signaling in Astrocytes Regulates Hippocampal Synaptic Plasticity and Cognitive Function of the Healthy CNS.

    Hosseini, Shirin; Michaelsen-Preusse, Kristin; Grigoryan, Gayane; Chhatbar, Chintan; Kalinke, Ulrich; Korte, Martin; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany.
    Type I interferon receptor (IFNAR) signaling is a hallmark of viral control and host protection. Here, we show that, in the hippocampus of healthy IFNAR-deficient mice, synapse number and synaptic plasticity, as well as spatial learning, are impaired. This is also the case for IFN-β-deficient animals. Moreover, antibody-mediated IFNAR blocking acutely interferes with neuronal plasticity, whereas a low-dose application of IFN-β has a positive effect on dendritic spine structure. Interfering with IFNAR signaling in different cell types shows a role for cognitive function and synaptic plasticity specifically mediated by astrocytes. Intriguingly, levels of the astrocytic glutamate-aspartate transporter (GLAST) are reduced significantly upon IFN-β treatment and increase following inhibition of IFNAR signaling. These results indicate that, besides the prominent role for host defense, IFNAR is important for synaptic plasticity as well as cognitive function. Astrocytes are at the center stage of this so-far-unknown signaling cascade.
  • Human Lentiviral Gene Therapy Restores the Cellular Phenotype of Autosomal Recessive Complete IFN-γR1 Deficiency.

    Hahn, Katharina; Pollmann, Liart; Nowak, Juliette; Nguyen, Ariane Hai Ha; Haake, Kathrin; Neehus, Anna-Lena; Waqas, Syed F Hassnain; Pessler, Frank; Baumann, Ulrich; Hetzel, Miriam; et al. (Elsevier(Cell Press), 2020-04-11)
    Autosomal recessive (AR) complete interferon-γ receptor 1 (IFN-γR1) deficiency, also known as one genetic etiology of Mendelian susceptibility to mycobacterial disease (MSMD), is a life-threatening congenital disease leading to premature death. Affected patients present a pathognomonic predisposition to recurrent and severe infections with environmental mycobacteria or the Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccine. Current therapeutic options are limited to antibiotic treatment and hematopoietic stem cell transplantation, however with poor outcome. Given the clinical success of gene therapy, we introduce the first lentiviral-based gene therapy approach to restore expression and function of the human IFN-γR-downstream signaling cascade. In our study, we developed lentiviral vectors constitutively expressing the human IFN-γR1 and demonstrate stable transgene expression without interference with cell viability and proliferation in transduced human hematopoietic cells. Using an IFN-γR1-deficient HeLa cell model, we show stable receptor reconstitution and restored IFN-γR1 signaling without adverse effect on cell functionality. Transduction of both SV40-immortalized and primary fibroblasts derived from IFN-γR1-deficient MSMD patients was able to recover IFN-γR1 expression and restore type II IFN signaling upon stimulation with IFN-γ. In summary, we highlight lentiviral vectors to correct the IFN-γ mediated immunity and present the first gene therapy approach for patients suffering from AR complete IFN-γR1 deficiency.
  • Presence of hepatitis B virus in synovium and its clinical significance in rheumatoid arthritis.

    Chen, Yu-Lan; Jing, Jun; Mo, Ying-Qian; Ma, Jian-Da; Yang, Li-Juan; Chen, Le-Feng; Zhang, Xiang; Yan, Tao; Zheng, Dong-Hui; Pessler, Frank; et al. (BMC, 2018-06-19)
    Previous studies have revealed that hepatitis B virus (HBV) infection may be related to rheumatoid arthritis (RA), but there are no studies on the presence of HBV antigens or nucleic acid in synovium from patients with RA with HBV infection. In the present study, we investigated the presence of HBV in the synovium and its clinical significance in RA. METHODS: Fifty-seven consecutive patients with active RA (Disease Activity Score 28-joint assessment based on C-reactive protein ≥ 2.6) and available synovial tissue who had completed 1 year of follow-up were recruited from a prospective cohort. The patients were divided into chronic HBV infection (CHB, n = 11) and non-CHB groups according to baseline HBV infection status. Clinical data were collected at baseline and at 1-, 3-, 6-, and 12-month follow-up. Radiographic changes of hand/wrist at baseline and month 12 were assessed with the Sharp/van der Heijde-modified Sharp score (mTSS). HBV in synovium was determined by immunohistochemical staining for hepatitis B virus surface antigen and hepatitis B virus core antigen (HBcAg) and by nested PCR for the HBV S gene. RESULTS: HBcAg was found in the synovium of patients with RA with CHB (7 of 11, 64%), which was confirmed by PCR for the HBV S gene. Compared with the non-CHB group, more CD68-positive macrophages, CD20-positive B cells, and CD15-positive neutrophils infiltrated the synovium in the CHB group (all p <  0.05). There were smaller improvements from baseline in most disease activity indicators mainly at month 12, and a significantly higher percentage of CHB patients experienced 1-year radiographic progression (ΔmTSS ≥ 0.5 unit/yr, 64% vs. 26%, p = 0.024). Multivariate logistic regression analysis showed that CHB status (OR 14.230, 95% CI 2.213-95.388; p = 0.006) and the density of synovial CD68-positive macrophages (OR 1.002, 95% CI 1.001-1.003; p = 0.003) were independently associated with 1-year radiographic progression. CONCLUSIONS: The presence of HBV in RA synovium may be involved in the pathogenesis of local lesions and exacerbate disease progression in RA.
  • Patient iPSC-Derived Macrophages to Study Inborn Errors of the IFN-γ Responsive Pathway.

    Haake, Kathrin; Neehus, Anna-Lena; Buchegger, Theresa; Kühnel, Mark Philipp; Blank, Patrick; Philipp, Friederike; Oleaga-Quintas, Carmen; Schulz, Ansgar; Grimley, Michael; Goethe, Ralph; et al. (MDPI, 2020-02-19)
    nterferon γ (IFN-γ) was shown to be a macrophage activating factor already in 1984. Consistently, inborn errors of IFN-γ immunity underlie Mendelian Susceptibility to Mycobacterial Disease (MSMD). MSMD is characterized by genetic predisposition to disease caused by weakly virulent mycobacterial species. Paradoxically, macrophages from patients with MSMD were little tested. Here, we report a disease modeling platform for studying IFN-γ related pathologies using macrophages derived from patient specific induced pluripotent stem cells (iPSCs). We used iPSCs from patients with autosomal recessive complete- and partial IFN-γR2 deficiency, partial IFN-γR1 deficiency and complete STAT1 deficiency. Macrophages from all patient iPSCs showed normal morphology and IFN-γ-independent functionality like phagocytic uptake of bioparticles and internalization of cytokines. For the IFN-γ-dependent functionalities, we observed that the deficiencies played out at various stages of the IFN-γ pathway, with the complete IFN-γR2 and complete STAT1 deficient cells showing the most severe phenotypes, in terms of upregulation of surface markers and induction of downstream targets. Although iPSC-derived macrophages with partial IFN-γR1 and IFN-γR2 deficiency still showed residual induction of downstream targets, they did not reduce the mycobacterial growth when challenged with Bacillus Calmette-Guérin. Taken together, we report a disease modeling platform to study the role of macrophages in patients with inborn errors of IFN-γ immunity.
  • Non-canonical Caspase-1 Signaling Drives RIP2-Dependent and TNF-α-Mediated Inflammation In Vivo.

    Reinke, Sören; Linge, Mary; Diebner, Hans H; Luksch, Hella; Glage, Silke; Gocht, Anne; Robertson, Avril A B; Cooper, Matthew A; Hofmann, Sigrun R; Naumann, Ronald; et al.
    Pro-inflammatory caspase-1 is a key player in innate immunity. Caspase-1 processes interleukin (IL)-1β and IL-18 to their mature forms and triggers pyroptosis. These caspase-1 functions are linked to its enzymatic activity. However, loss-of-function missense mutations in CASP1 do not prevent autoinflammation in patients, despite decreased IL-1β production. In vitro data suggest that enzymatically inactive caspase-1 drives inflammation via enhanced nuclear factor κB (NF-κB) activation, independent of IL-1β processing. Here, we report two mouse models of enzymatically inactive caspase-1-C284A, demonstrating the relevance of this pathway in vivo. In contrast to Casp1-/- mice, caspase-1-C284A mice show pronounced hypothermia and increased levels of the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and IL-6 when challenged with lipopolysaccharide (LPS). Caspase-1-C284A signaling is RIP2 dependent and mediated by TNF-α but independent of the NLRP3 inflammasome. LPS-stimulated whole blood from patients carrying loss-of-function missense mutations in CASP1 secretes higher amounts of TNF-α. Taken together, these results reveal non-canonical caspase-1 signaling in vivo.
  • Selective reconstitution of IFN‑γ gene function in Ncr1+ NK cells is sufficient to control systemic vaccinia virus infection.

    Borst, Katharina; Flindt, Sven; Blank, Patrick; Larsen, Pia-Katharina; Chhatbar, Chintan; Skerra, Jennifer; Spanier, Julia; Hirche, Christoph; König, Martin; Alanentalo, Tomas; et al. (PLOS, 2020-02-01)
    IFN-γ is an enigmatic cytokine that shows direct anti-viral effects, confers upregulation of MHC-II and other components relevant for antigen presentation, and that adjusts the composition and balance of complex cytokine responses. It is produced during immune responses by innate as well as adaptive immune cells and can critically affect the course and outcome of infectious diseases, autoimmunity, and cancer. To selectively analyze the function of innate immune cell-derived IFN-γ, we generated conditional IFN-γOFF mice, in which endogenous IFN-γ expression is disrupted by a loxP flanked gene trap cassette inserted into the first intron of the IFN-γ gene. IFN-γOFF mice were intercrossed with Ncr1-Cre or CD4-Cre mice that express Cre mainly in NK cells (IFN-γNcr1-ON mice) or T cells (IFN-γCD4-ON mice), respectively. Rosa26RFP reporter mice intercrossed with Ncr1-Cre mice showed selective RFP expression in more than 80% of the NK cells, while upon intercrossing with CD4-Cre mice abundant RFP expression was detected in T cells, but also to a minor extent in other immune cell subsets. Previous studies showed that IFN-γ expression is needed to promote survival of vaccinia virus (VACV) infection. Interestingly, during VACV infection of wild type and IFN-γCD4-ON mice two waves of serum IFN-γ were induced that peaked on day 1 and day 3/4 after infection. Similarly, VACV infected IFN-γNcr1-ON mice mounted two waves of IFN-γ responses, of which the first one was moderately and the second one profoundly reduced when compared with WT mice. Furthermore, IFN-γNcr1-ON as well as IFN-γCD4-ON mice survived VACV infection, whereas IFN-γOFF mice did not. As expected, ex vivo analysis of splenocytes derived from VACV infected IFN-γNcr1-ON mice showed IFN-γ expression in NK cells, but not T cells, whereas IFN-γOFF mice showed IFN-γ expression neither in NK cells nor T cells. VACV infected IFN-γNcr1-ON mice mounted normal cytokine responses, restored neutrophil accumulation, and showed normal myeloid cell distribution in blood and spleen. Additionally, in these mice normal MHC-II expression was detected on peripheral macrophages, whereas IFN-γOFF mice did not show MHC-II expression on such cells. In conclusion, upon VACV infection Ncr1 positive cells including NK cells mount two waves of early IFN-γ responses that are sufficient to promote the induction of protective anti-viral immunity.
  • IL-7 derived from lymph node fibroblastic reticular cells is dispensable for naive T cell homeostasis but crucial for central memory T cell survival.

    Knop, Laura; Deiser, Katrin; Bank, Ute; Witte, Amelie; Mohr, Juliane; Philipsen, Lars; Fehling, Hans J; Müller, Andreas J; Kalinke, Ulrich; Schüler, Thomas; et al. (Wiley Online Open, 2020-02-11)
    The survival of peripheral T cells is dependent on their access to peripheral lymph nodes (pLNs) and stimulation by Interleukin-7 (IL-7). In pLNs fibroblastic reticular cells (FRCs) and lymphatic endothelial cells (LECs) produce IL-7 suggesting their contribution to the IL-7-dependent survival of T cells. However, IL-7 production is detectable in multiple organs and is not restricted to pLNs. This raises the question whether pLN-derived IL-7 is required for the maintenance of peripheral T cell homeostasis. Here, we show that numbers of naive T cells (TN ) remain unaffected in pLNs and spleen of mice lacking Il7 gene activity in pLN FRCs, LECs or both. In contrast, frequencies of central memory T cells (TCM ) are reduced in FRC-specific IL-7 knockout mice. Thus, steady state IL-7 production by pLN FRCs is critical for the maintenance of TCM , but not TN , indicating that both T cell subsets colonize different ecological niches in vivo. This article is protected by copyright. All rights reserved.
  • The deubiquitinase OTUB1 augments NF-κB-dependent immune responses in dendritic cells in infection and inflammation by stabilizing UBC13.

    Mulas, Floriana; Wang, Xu; Song, Shanshan; Nishanth, Gopala; Yi, Wenjing; Brunn, Anna; Larsen, Pia-Katharina; Isermann, Berend; Kalinke, Ulrich; Barragan, Antonio; et al. (Springer Nature, 2020-02-05)
    Dendritic cells (DCs) are indispensable for defense against pathogens but may also contribute to immunopathology. Activation of DCs upon the sensing of pathogens by Toll-like receptors (TLRs) is largely mediated by pattern recognition receptor/nuclear factor-κB (NF-κB) signaling and depends on the appropriate ubiquitination of the respective signaling molecules. However, the ubiquitinating and deubiquitinating enzymes involved and their interactions are only incompletely understood. Here, we reveal that the deubiquitinase OTU domain, ubiquitin aldehyde binding 1 (OTUB1) is upregulated in DCs upon murine Toxoplasma gondii infection and lipopolysaccharide challenge. Stimulation of DCs with the TLR11/12 ligand T. gondii profilin and the TLR4 ligand lipopolysaccharide induced an increase in NF-κB activation in OTUB1-competent cells, resulting in elevated interleukin-6 (IL-6), IL-12, and tumor necrosis factor (TNF) production, which was also observed upon the specific stimulation of TLR2, TLR3, TLR7, and TLR9. Mechanistically, OTUB1 promoted NF-κB activity in DCs by K48-linked deubiquitination and stabilization of the E2-conjugating enzyme UBC13, resulting in increased K63-linked ubiquitination of IRAK1 (IL-1 receptor-associated kinase 1) and TRAF6 (TNF receptor-associated factor 6). Consequently, DC-specific deletion of OTUB1 impaired the production of cytokines, in particular IL-12, by DCs over the first 2 days of T. gondii infection, resulting in the diminished production of protective interferon-γ (IFN-γ) by natural killer cells, impaired control of parasite replication, and, finally, death from chronic T. encephalitis, all of which could be prevented by low-dose IL-12 treatment in the first 3 days of infection. In contrast, impaired OTUB1-deficient DC activation and cytokine production by OTUB1-deficient DCs protected mice from lipopolysaccharide-induced immunopathology. Collectively, these findings identify OTUB1 as a potent novel regulator of DCs during infectious and inflammatory diseases.
  • Obstetric Ultrasonography to Detect Fetal Abnormalities in a Mouse Model for Zika Virus Infection.

    Forster, Dominik; Schwarz, Jan Hendrik; Brosinski, Katrin; Kalinke, Ulrich; Sutter, Gerd; Volz, Asisa; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (MDPI, 2020-01-07)
    In 2015 Zika virus (ZIKV) emerged for the first time in South America. The following ZIKV epidemic resulted in the appearance of a clinical phenotype with microcephaly and other severe malformations in newborns. So far, mechanisms of ZIKV induced damage to the fetus are not completely understood. Previous data suggest that ZIKV may bypass the placenta to reach the fetus. Thus, animal models for ZIKV infection are important to facilitate studies about ZIKV infection during pregnancy. Here, we used ultrasound based imaging (USI) to characterize ZIKV induced pathogenesis in the pregnant Type I interferon receptor-deficient (IFNAR-/-) mouse model. Based on USI we suggest the placenta to be a primary target organ of ZIKV infection enabling ZIKV spreading to the fetus. Moreover, in addition to direct infection of the fetus, the placental ZIKV infection may cause an indirect damage to the fetus through reduced uteroplacental perfusion leading to intrauterine growth retardation (IUGR) and fetal complications as early as embryonic day (ED) 12.5. Our data confirmed the capability of USI to characterize ZIKV induced modifications in mouse fetuses. Data from further studies using USI to monitor ZIKV infections will contribute to a better understanding of ZIKV infection in pregnant IFNAR-/- mice.
  • A dual role for hepatocyte-intrinsic canonical NF-κB signaling in virus control.

    Namineni, Sukumar; O'Connor, Tracy; Faure-Dupuy, Suzanne; Johansen, Pål; Riedl, Tobias; Liu, Kaijing; Xu, Haifeng; Singh, Indrabahadur; Shinde, Prashant; Li, Fanghui; et al. (Elsevier, 2020-01-15)
    Using lymphocytic choriomeningitis virus (LCMV) as a model of liver infection, we first assessed the role of myeloid cells by depletion prior to infection. We investigated the role of hepatocyte-intrinsic innate immune signaling by infecting mice lacking canonical NF-κB signaling (IKKβΔHep) specifically in hepatocytes. In addition, mice lacking hepatocyte-specific interferon-α/β signaling-(IFNARΔHep), or interferon-α/β signaling in myeloid cells-(IFNARΔMyel) were infected.
  • Control of Nipah Virus Infection in Mice by the Host Adaptors Mitochondrial Antiviral Signaling Protein (MAVS) and Myeloid Differentiation Primary Response 88 (MyD88).

    Iampietro, Mathieu; Aurine, Noemie; Dhondt, Kevin P; Dumont, Claire; Pelissier, Rodolphe; Spanier, Julia; Vallve, Audrey; Raoul, Herve; Kalinke, Ulrich; Horvat, Branka; et al. (Oxford Academic, 2019-12-19)
    Interferon (IFN) type I plays a critical role in the protection of mice from lethal Nipah virus (NiV) infection, but mechanisms responsible for IFN-I induction remain unknown. In the current study, we demonstrated the critical role of the mitochondrial antiviral signaling protein signaling pathway in IFN-I production and NiV replication in murine embryonic fibroblasts in vitro, and the redundant but essential roles of both mitochondrial antiviral signaling protein and myeloid differentiation primary response 88 adaptors, but not TRIF (Toll/Interleukin-1 receptor/Resistance [TIR] domain-containing adaptor-inducing IFN-β), in the control of NiV infection in mice. These results reveal potential novel targets for antiviral intervention and help in understanding NiV immunopathogenesis.
  • Phosphatidylcholine PC ae C44:6 in cerebrospinal fluid is a sensitive biomarker for bacterial meningitis.

    de Araujo, Leonardo Silva; Pessler, Kevin; Sühs, Kurt-Wolfram; Novoselova, Natalia; Klawonn, Frank; Kuhn, Maike; Kaever, Volkhard; Müller-Vahl, Kirsten; Trebst, Corinna; Skripuletz, Thomas; et al. (BioMed Central (BMC), 2020-01-07)
    BACKGROUND: The timely diagnosis of bacterial meningitis is of utmost importance due to the need to institute antibiotic treatment as early as possible. Moreover, the differentiation from other causes of meningitis/encephalitis is critical because of differences in management such as the need for antiviral or immunosuppressive treatments. Considering our previously reported association between free membrane phospholipids in cerebrospinal fluid (CSF) and CNS involvement in neuroinfections we evaluated phosphatidylcholine PC ae C44:6, an integral constituent of cell membranes, as diagnostic biomarker for bacterial meningitis. METHODS: We used tandem mass spectrometry to measure concentrations of PC ae C44:6 in cell-free CSF samples (n = 221) from patients with acute bacterial meningitis, neuroborreliosis, viral meningitis/encephalitis (herpes simplex virus, varicella zoster virus, enteroviruses), autoimmune neuroinflammation (anti-NMDA-receptor autoimmune encephalitis, multiple sclerosis), facial nerve and segmental herpes zoster (shingles), and noninflammatory CNS disorders (Bell's palsy, Tourette syndrome, normal pressure hydrocephalus). RESULTS: PC ae C44:6 concentrations were significantly higher in bacterial meningitis than in all other diagnostic groups, and were higher in patients with a classic bacterial meningitis pathogen (e.g. Streptococcus pneumoniae, Neisseria meningitidis, Staphylococcus aureus) than in those with less virulent or opportunistic pathogens as causative agents (P = 0.026). PC ae C44:6 concentrations were only moderately associated with CSF cell count (Spearman's ρ = 0.45; P = 0.009), indicating that they do not merely reflect neuroinflammation. In receiver operating characteristic curve analysis, PC ae C44:6 equaled CSF cell count in the ability to distinguish bacterial meningitis from viral meningitis/encephalitis and autoimmune CNS disorders (AUC 0.93 both), but had higher sensitivity (91% vs. 41%) and negative predictive value (98% vs. 89%). A diagnostic algorithm comprising cell count, lactate and PC ae C44:6 had a sensitivity of 97% (specificity 87%) and negative predictive value of 99% (positive predictive value 61%) and correctly diagnosed three of four bacterial meningitis samples that were misclassified by cell count and lactate due to low values not suggestive of bacterial meningitis. CONCLUSIONS: Increased CSF PC ae C44:6 concentrations in bacterial meningitis likely reflect ongoing CNS cell membrane stress or damage and have potential as additional, sensitive biomarker to diagnose bacterial meningitis in patients with less pronounced neuroinflammation.
  • A Soluble Version of Nipah Virus Glycoprotein G Delivered by Vaccinia Virus MVA Activates Specific CD8 and CD4 T Cells in Mice.

    Kalodimou, Georgia; Veit, Svenja; Jany, Sylvia; Kalinke, Ulrich; Broder, Christopher C; Sutter, Gerd; Volz, Asisa; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (MDPI, 2019-12-24)
    Nipah virus (NiV) is an emerging zoonotic virus that is transmitted by bats to humans and to pigs, causing severe respiratory disease and often fatal encephalitis. Antibodies directed against the NiV-glycoprotein (G) protein are known to play a major role in clearing NiV infection and in providing vaccine-induced protective immunity. More recently, T cells have been also shown to be involved in recovery from NiV infection. So far, relatively little is known about the role of T cell responses and the antigenic targets of NiV-G that are recognized by CD8 T cells. In this study, NiV-G protein served as the target immunogen to activate NiV-specific cellular immune responses. Modified Vaccinia virus Ankara (MVA), a safety-tested strain of vaccinia virus for preclinical and clinical vaccine research, was used for the generation of MVA-NiV-G candidate vaccines expressing different versions of recombinant NiV-G. Overlapping peptides covering the entire NiV-G protein were used to identify major histocompatibility complex class I/II-restricted T cell responses in type I interferon receptor-deficient (IFNAR-/-) mice after vaccination with the MVA-NiV-G candidate vaccines. We have identified an H2-b-restricted nonamer peptide epitope with CD8 T cell antigenicity and a H2-b 15mer with CD4 T cell antigenicity in the NiV-G protein. The identification of this epitope and the availability of the MVA-NiV-G candidate vaccines will help to evaluate NiV-G-specific immune responses and the potential immune correlates of vaccine-mediated protection in the appropriate murine models of NiV-G infection. Of note, a soluble version of NiV-G was advantageous in activating NiV-G-specific cellular immune responses using these peptides
  • Type I Interferon Signaling Disrupts the Hepatic Urea Cycle and Alters Systemic Metabolism to Suppress T Cell Function.

    Lercher, Alexander; Bhattacharya, Anannya; Popa, Alexandra M; Caldera, Michael; Schlapansky, Moritz F; Baazim, Hatoon; Agerer, Benedikt; Gürtl, Bettina; Kosack, Lindsay; Májek, Peter; et al. (Elsevier/ Cel Press, 2019-12-17)
    Infections induce complex host responses linked to antiviral defense, inflammation, and tissue damage and repair. We hypothesized that the liver, as a central metabolic hub, may orchestrate systemic metabolic changes during infection. We infected mice with chronic lymphocytic choriomeningitis virus (LCMV), performed RNA sequencing and proteomics of liver tissue, and integrated these data with serum metabolomics at different infection phases. Widespread reprogramming of liver metabolism occurred early after infection, correlating with type I interferon (IFN-I) responses. Viral infection induced metabolic alterations of the liver that depended on the interferon alpha/beta receptor (IFNAR1). Hepatocyte-intrinsic IFNAR1 repressed the transcription of metabolic genes, including Otc and Ass1, which encode urea cycle enzymes. This led to decreased arginine and increased ornithine concentrations in the circulation, resulting in suppressed virus-specific CD8+ T cell responses and ameliorated liver pathology. These findings establish IFN-I-induced modulation of hepatic metabolism and the urea cycle as an endogenous mechanism of immunoregulation. VIDEO ABSTRACT.

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