• Deconvolution of bulk blood eQTL effects into immune cell subpopulations.

      Aguirre-Gamboa, Raúl; de Klein, Niek; di Tommaso, Jennifer; Claringbould, Annique; van der Wijst, Monique Gp; de Vries, Dylan; Brugge, Harm; Oelen, Roy; Võsa, Urmo; Zorro, Maria M; et al. (BMC, 2020-06-12)
      A novel planctomycetal strain, designated Pla85_3_4T, was isolated from the surface of wood incubated at the discharge of a wastewater treatment plant in the Warnow river near Rostock, Germany. Cells of the novel strain have a cell envelope architecture resembling that of Gram-negative bacteria, are round to pear-shaped (length: 2.2 ± 0.4 µm, width: 1.2 ± 0.3 µm), form aggregates and divide by polar budding. Colonies have a cream colour. Strain Pla85_3_4T grows at ranges of 10-30 °C (optimum 26 °C) and at pH 6.5-10.0 (optimum 7.5), and has a doubling time of 26 h. Phylogenetically, strain Pla85_3_4T (DSM 103796T = LMG 29741T) is concluded to represent a novel species of a novel genus within the family Pirellulaceae, for which we propose the name Lignipirellula cremea gen. nov., sp. nov.
    • Degradable magnesium implant-associated infections by bacterial biofilms induce robust localized and systemic inflammatory reactions in a mouse model.

      Rahim, Muhammad Imran; Babbar, Anshu; Lienenklaus, Stefan; Pils, Marina; Rohde, M; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2017-06-01)
      Biomaterial-associated Pseudomonas aeruginosa biofilm infections constitute cascade of host immune reactions ultimately leading towards implant failure. Due to lack of relevant in vivo biofilm models, majority of the studies report host immune responses against free living or planktonic bacteria while bacteria in clinical situations live more frequently as biofilm communities than as single cells. Present study investigated host immune responses against biomaterial-associated P. aeruginosa biofilms in a clinically relevant mouse model. Previously, we reported metallic magnesium, a prospective biodegradable implant, to be permissive for bacterial biofilms in vivo even though it exhibits antibacterial properties in vitro. Therefore, magnesium was employed as biomaterial to investigate in vivo biofilm formation and associated host immune responses by using two P. aeruginosa strains and two mouse strains. P. aeruginosa formed biofilms on subcutaneously implanted magnesium discs. Non-invasive in vivo imaging indicated transient inflammatory responses at control sites whereas robust prolonged interferon-β (IFN-β) expression was observed from biofilms in a transgenic animal reporter. Further, immunohistology and electron microscopic results showed that bacterial biofilms were located in two dimensions immediately on the implant surface and at a short distance in the adjacent tissue. These biofilms were surrounded by inflammatory cells (mainly polymorphonuclear cells) as compared to controls. Interestingly, even though the number of live bacteria in various organs remained below detectable levels, splenomegaly indicated systemic inflammatory processes. Overall, these findings confirmed the resistance of biofilm infections in vivo to potentially antibacterial properties of magnesium degradation products. In vivo imaging and histology indicated the induction of both, local and systemic host inflammatory responses against P. aeruginosa biofilms. Even though the innate host immune defenses could not eliminate the local infection for up to two weeks, there was no apparent systemic bacteremia and all animals investigated survived the infection.
    • Dengue-specific subviral nanoparticles: design, creation and characterization.

      Khetarpal, Niyati; Poddar, Ankur; Nemani, Satish K; Dhar, Nisha; Patil, Aravind; Negi, Priyanka; Perween, Ashiya; Viswanathan, Ramaswamy; Lünsdorf, Heinrich; Tyagi, Poornima; et al. (2013)
      Dengue is today the most significant of arboviral diseases. Novel tools are necessary to effectively address the problem of dengue. Virus-like particles (VLP) offer a versatile nanoscale platform for developing tools with potential biomedical applications. From the perspective of a potentially useful dengue-specific tool, the dengue virus envelope protein domain III (EDIII), endowed with serotype-specificity, host receptor recognition and the capacity to elicit virus-neutralizing antibodies, is an attractive candidate.
    • Designation of type strains for seven species of the order Myxococcales and proposal for neotype strains of Cystobacter ferrugineus, Cystobacter minus and Polyangium fumosum.

      Lang, Elke; Reichenbach, Hans; Leibniz-Institut DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Inhoffenstrasse 7B, 38124 Braunschweig, Germany (2013-11)
      Ten species of the order Myxococcales with validly published names are devoid of living type strains. Four species of the genus Chondromyces are represented by dead herbarium samples as the type material. For a species of the genus Melittangium and two species of the genus Polyangium, no physical type material was assigned at the time of validation of the names or later on. In accordance with rule 18f of the International Code of Nomenclature of Bacteria the following type strains are designated for these species: strain Cm a14(T) ( = DSM 14605(T) = JCM 12615(T)) as the type strain of Chondromyces apiculatus, strain Cm c5(T) ( = DSM 14714(T) = JCM 12616(T)) as the type strain of Chondromyces crocatus, strain Sy t2(T) ( = DSM 14631(T) = JCM 12617(T)) as the type strain of Chondromyces lanuginosus, strain Cm p51(T) ( = DSM 14607(T) = JCM 12618(T)) as the type strain of Chondromyces pediculatus, strain Me b8(T) ( = DSM 14713(T) = JCM 12633(T)) as the type strain of Melittangium boletus, strain Pl s12(T) ( = DSM 14670(T) = JCM 12637(T)) as the type strain of Polyangium sorediatum and strain Pl sm5(T) ( = DSM 14734(T) = JCM 12638(T)) as the type strain of Polyangium spumosum. Furthermore, the type strains given for three species of the genera Cystobacter and Polyangium had been kept at one university institute and have been lost according to our investigations. In accordance with Rule 18c of the Bacteriological Code, we propose the following neotype strains: strain Cb fe18 ( = DSM 14716  = JCM 12624) as the neotype strain of Cystobacter ferrugineus, strain Cb m2 ( = DSM 14751 = JCM 12627) as the neotype strain of Cystobacter minus and strain Pl fu5 ( = DSM 14668 = JCM 12636) as the neotype strain of Polyangium fumosum. The proposals of the strains are based on the descriptions and strain proposals given in the respective chapters of Bergey's Manual of Systematic Bacteriology (2005).
    • The Deubiquitinating Enzyme Cylindromatosis Dampens CD8(+) T Cell Responses and Is a Critical Factor for Experimental Cerebral Malaria and Blood-Brain Barrier Damage.

      Schmid, Ursula; Stenzel, Werner; Koschel, Josephin; Raptaki, Maria; Wang, Xu; Naumann, Michael; Matuschewski, Kai; Schlüter, Dirk; Nishanth, Gopala; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2017)
      Cerebral malaria is a severe complication of human malaria and may lead to death of Plasmodium falciparum-infected individuals. Cerebral malaria is associated with sequestration of parasitized red blood cells within the cerebral microvasculature resulting in damage of the blood-brain barrier and brain pathology. Although CD8(+) T cells have been implicated in the development of murine experimental cerebral malaria (ECM), several other studies have shown that CD8(+) T cells confer protection against blood-stage infections. Since the role of host deubiquitinating enzymes (DUBs) in malaria is yet unknown, we investigated how the DUB cylindromatosis (CYLD), an important inhibitor of several cellular signaling pathways, influences the outcome of ECM. Upon infection with Plasmodium berghei ANKA (PbA) sporozoites or PbA-infected red blood cells, at least 90% of Cyld(-/-) mice survived the infection, whereas all congenic C57BL/6 mice displayed signatures of ECM, impaired parasite control, and disruption of the blood-brain barrier integrity. Cyld deficiency prevented brain pathology, including hemorrhagic lesions, enhanced activation of astrocytes and microglia, infiltration of CD8(+) T cells, and apoptosis of endothelial cells. Furthermore, PbA-specific CD8(+) T cell responses were augmented in the blood of Cyld(-/-) mice with increased production of interferon-γ and granzyme B and elevated activation of protein kinase C-θ and nuclear factor "kappa light-chain enhancer" of activated B cells. Importantly, accumulation of CD8(+) T cells in the brain of Cyld(-/-) mice was significantly reduced compared to C57BL/6 mice. Bone marrow chimera experiments showed that the absence of ECM signatures in infected Cyld(-/-) mice could be attributed to hematopoietic and radioresistant parenchymal cells, most likely endothelial cells that did not undergo apoptosis. Together, we were able to show that host deubiqutinating enzymes play an important role in ECM and that CYLD promotes ECM supporting it as a potential therapeutic target for adjunct therapy to prevent cerebral complications of severe malaria.
    • Developmental induction of human T-cell responses against Candida albicans and Aspergillus fumigatus.

      Vogel, Katrin; Pierau, Mandy; Arra, Aditya; Lampe, Karen; Schlueter, Dirk; Arens, Christoph; Brunner-Weinzierl, Monika C; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Nature publishing group, 2018-11-15)
      The origin of human T-cell responses against fungal pathogens early in life is not clearly understood. Here, we show that antifungal T-cell responses are vigorously initiated within the first years of life against lysates and peptides of Candida albicans or Aspergillus fumigatus, presented by autologous monocytes. The neonatal responding T-cell pool consists of 20 different TCR-V
    • Die nicht-alkoholische Fettlebererkrankung : Die Rolle der Leber im metabolischen Syndrom

      Jupa, K.L.; Manns, M.P.; Jäckel, E; DZIF,Deutsches Zentrum für Infektionsforschung; HZI, Helmholtz-Zentrum für Infektiondforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig.
      Epidemiologie Die nicht-alkoholische Fettlebererkrankung (»non-alcoholic fatty liver disease«, NAFLD) ist mittlerweile eine der häufigsten Lebererkrankung weltweit mit einer mittleren Prävalenz von 20% weltweit und bis zu 30% in Europa [1]. Als Hauptrisikofaktoren gelten einerseits verschiedene Umweltfaktoren, insbesondere Bewegungsmangel und falsche Ernährung sowie andererseits die verschiedenen Aspekte des metabolischen Syndroms: Adipositas, Fettstoffwechselstörungen sowie Insulinresistenz und Diabetes mellitus Typ 2. Aus diesem Grund wird die Fettleber mittlerweile auch als hepatische Komponente des metabolischen Syndroms bezeichnet. Neben den Umweltfaktoren konnte auch gezeigt werden, dass eine genetische Prädisposition im Sinne von einem Adiponutrin Polymorphismus (»patatin-like phospholipase domain containing 3«, PNPLA3 [2, 3] zu einem gehäuften Auftreten einer Fettlebererkrankung führen kann.
    • Differential magnesium implant corrosion coat formation and contribution to bone bonding.

      Rahim, Muhammad Imran; Weizbauer, Andreas; Evertz, Florian; Hoffmann, Andrea; Rohde, M; Glasmacher, Birgit; Windhagen, Henning; Gross, Gerhard; Seitz, Jan-Marten; Mueller, Peter P; et al. (2017)
      Magnesium alloys are presently under investigation as promising biodegradable implant materials with osteoconductive properties. To study the molecular mechanisms involved, the potential contribution of soluble magnesium corrosion products to the stimulation of osteoblastic cell differentiation was examined. However, no evidence for the stimulation of osteoblast differentiation could be obtained when cultured mesenchymal precursor cells were differentiated in the presence of metallic magnesium or in cell culture medium containing elevated magnesium ion levels. Similarly, in soft tissue no bone induction by metallic magnesium or by the corrosion product magnesium hydroxide could be observed in a mouse model. Motivated by the comparatively rapid accumulation solid corrosion products physicochemical processes were examined as an alternative mechanism to explain the stimulation of bone growth by magnesium-based implants. During exposure to physiological solutions a structured corrosion coat formed on magnesium whereby the elements calcium and phosphate were enriched in the outermost layer which could play a role in the established biocompatible behavior of magnesium implants. When magnesium pins were inserted into avital bones, corrosion lead to increases in the pull out force, suggesting that the expanding corrosion layer was interlocking with the surrounding bone. Since mechanical stress is a well-established inducer of bone growth, volume increases caused by the rapid accumulation of corrosion products and the resulting force development could be a key mechanism and provide an explanation for the observed stimulatory effects of magnesium-based implants in hard tissue. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 697-709, 2017.
    • Divergent co-transcriptomes of different host cells infected with Toxoplasma gondii reveal cell type-specific host-parasite interactions.

      Swierzy, Izabela J; Händel, Ulrike; Kaever, Alexander; Jarek, Michael; Scharfe, Maren; Schlüter, Dirk; Lüder, Carsten G K; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2017-08-03)
      The apicomplexan parasite Toxoplasma gondii infects various cell types in avian and mammalian hosts including humans. Infection of immunocompetent hosts is mostly asymptomatic or benign, but leads to development of largely dormant bradyzoites that persist predominantly within neurons and muscle cells. Here we have analyzed the impact of the host cell type on the co-transcriptomes of host and parasite using high-throughput RNA sequencing. Murine cortical neurons and astrocytes, skeletal muscle cells (SkMCs) and fibroblasts differed by more than 16,200 differentially expressed genes (DEGs) before and after infection with T. gondii. However, only a few hundred of them were regulated by infection and these largely diverged in neurons, SkMCs, astrocytes and fibroblasts indicating host cell type-specific transcriptional responses after infection. The heterogeneous transcriptomes of host cells before and during infection coincided with ~5,400 DEGs in T. gondii residing in different cell types. Finally, we identified gene clusters in both T. gondii and its host, which correlated with the predominant parasite persistence in neurons or SkMCs as compared to astrocytes or fibroblasts. Thus, heterogeneous expression profiles of different host cell types and the parasites' ability to adapting to them may govern the parasite-host cell interaction during toxoplasmosis.
    • DSA are associated with more graft injury, more fibrosis and upregulation of rejection associated transcripts in subclinical rejection.

      Höfer, Anne; Jonigk, Danny; Hartleben, Björn; Verboom, Murielle; Hallensleben, Michael; Hübscher, Stefan G; Manns, Michael P; Jaeckel, Elmar; Taubert, Richard; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Lippincott, Williams & Wilkins , 2019-10-23)
      Background: Subclinical T cell-mediated rejection (subTCMR) is commonly found after liver transplantation and has a good short-term prognosis, even when it is left untreated. Donor-specific antibodies (DSA) are putatively associated with a worse prognosis for recipient and graft after liver transplantation. Methods: To assess the immune regulation in subTCMR grafts, gene expression of 93 transcripts for graft injury, tolerance and immune regulation was analyzed in 77 biopsies with “no histological rejection” (NHR; n=25), “clinical TCMR” (cTMCR; n=16) and subTCMR (n=36). In addition, all available subTCMR biopsies (n=71) were tested for DSA with bead assays. Results: SubTCMR showed heterogeneous and intermediate expression profiles of transcripts that were upregulated in cTCMR. Graft gene expression suggested a lower activation of effector lymphocytes and a higher activation of regulatory T cells in grafts with subTCMR compared to cTCMR.DSA positivity in subTCMR was associated with histological evidence of more severe graft inflammation and fibrosis. This more severe DSA+ associated graft injury in subTCMR was converged with an upregulation of cTCMR associated transcripts. In nonsupervised analysis DSA positive subTCMR mostly clustered together with cTCMR, while DSA negative subTCMR clustered together with NHR. Conclusion: T cell-mediated rejection seem to form a continuum of alloimmune activation. Although subTCMR exhibited less expression of TCMR associated transcript, DSA positivity in subTCMR was associated with an upregulation of rejection associated transcripts. The identification of DSA positive subclinical rejection might help to define patients with more inflammation in the graft and development of fibrosis.
    • Efficacy of rituximab in difficult-to-manage autoimmune hepatitis: Results from the International Autoimmune Hepatitis Group.

      Than, Nwe Ni; Hodson, James; Schmidt-Martin, Daniel; Taubert, Richard; Wawman, Rebecca E; Botter, Meemee; Gautam, Nishant; Bock, Kilian; Jones, Rebecca; Appanna, Gautham D; et al. (Elsevier, 2019-12-01)
      Twenty-two patients with type-1 AIH were included, with a median age of 40 years at diagnosis (range 19-79); 15/22 (68%) were female and 18/22 (82%) were Caucasian. The median period from diagnosis to the end of follow-up in these patients was 11 years (range 3-28). Values of alanine aminotransferase, aspartate aminotransferase and albumin improved significantly following rituximab therapy, and were sustained for up to 2 years (all p ≪0.001). Prednisolone doses were significantly reduced by 12 months post-treatment (p = 0.003), with 13/21 (62%) patients having a dose reduction. Over a median post-treatment follow-up period of 6 years (range 1-10), 5 patients developed AIH flares at a median of 22 months post-treatment, giving an estimated 71% freedom from AIH flare at 2 years. Four of these patients received a second course of treatment, of whom 2 had subsequent further flares. No serious adverse events attributable to rituximab were recorded.
    • An endothelial cell line infected by Kaposi's sarcoma-associated herpes virus (KSHV) allows the investigation of Kaposi's sarcoma and the validation of novel viral inhibitors in vitro and in vivo.

      Dubich, Tatyana; Lieske, Anna; Santag, Susann; Beauclair, Guillaume; Rückert, Jessica; Herrmann, Jennifer; Gorges, Jan; Büsche, Guntram; Kazmaier, Uli; Hauser, Hansjörg; et al. (2019-01-04)
      Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), a tumor of endothelial origin predominantly affecting immunosuppressed individuals. Up to date, vaccines and targeted therapies are not available. Screening and identification of anti-viral compounds are compromised by the lack of scalable cell culture systems reflecting properties of virus-transformed cells in patients. Further, the strict specificity of the virus for humans limits the development of in vivo models. In this study, we exploited a conditionally immortalized human endothelial cell line for establishment of in vitro 2D and 3D KSHV latency models and the generation of KS-like xenograft tumors in mice. Importantly, the invasive properties and tumor formation could be completely reverted by purging KSHV from the cells, confirming that tumor formation is dependent on the continued presence of KSHV, rather than being a consequence of irreversible transformation of the infected cells. Upon testing a library of 260 natural metabolites, we selected the compounds that induced viral loss or reduced the invasiveness of infected cells in 2D and 3D endothelial cell culture systems. The efficacy of selected compounds against KSHV-induced tumor formation was verified in the xenograft model. Together, this study shows that the combined use of anti-viral and anti-tumor assays based on the same cell line is predictive for tumor reduction in vivo and therefore allows faithful selection of novel drug candidates against Kaposi's sarcoma. KEY MESSAGES: Novel 2D, 3D, and xenograft mouse models mimic the consequences of KSHV infection. KSHV-induced tumorigenesis can be reverted upon purging the cells from the virus. A 3D invasiveness assay is predictive for tumor reduction in vivo. Chondramid B, epothilone B, and pretubulysin D diminish KS-like lesions in vivo.
    • Enteric Murine Ganglionitis Induced by Autoimmune CD8 T Cells Mimics Human Gastrointestinal Dysmotility.

      Sanchez-Ruiz, Monica; Brunn, Anna; Montesinos-Rongen, Manuel; Rudroff, Claudia; Hartmann, Melanie; Schlüter, Dirk; Pfitzer, Gabriele; Deckert, Martina; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Elsevier, 2018-12-27)
      Inflammatory bowel diseases frequently cause gastrointestinal dysmotility, suggesting that they may also affect the enteric nervous system. So far, the precise mechanisms that lead to gastrointestinal dysmotility in inflammatory bowel diseases have not been elucidated. To determine the effect of CD8 T cells on gastrointestinal motility, transgenic mice expressing ovalbumin on enteric neurons were generated. In these mice, adoptive transfer of ovalbumin-specific OT-I CD8 T cells induced severe enteric ganglionitis. CD8 T cells homed to submucosal and myenteric plexus neurons, 60% of which were lost, clinically resulting in severely impaired gastrointestinal transition. Anti-interferon-γ treatment rescued neurons by preventing their up-regulation of major histocompatibility complex class I antigen, thus preserving gut motility. These preclinical murine data translated well into human gastrointestinal dysmotility. In a series of 30 colonic biopsy specimens from patients with gastrointestinal dysmotility, CD8 T cell-mediated ganglionitis was detected that was followed by severe loss of enteric neurons (74.8%). Together, the preclinical and clinical data support the concept that autoimmune CD8 T cells play an important pathogenetic role in gastrointestinal dysmotility and may destroy enteric neurons.
    • Epigenome-wide association study of DNA methylation and adult asthma in the Agricultural Lung Health Study.

      Hoang, Thanh T; Sikdar, Sinjini; Xu, Cheng-Jian; Lee, Mi Kyeong; Cardwell, Jonathan; Forno, Erick; Imboden, Medea; Jeong, Ayoung; Madore, Anne-Marie; Qi, Cancan; et al. (European Respiratory Society (ERS), 2020-09-03)
      Epigenome-wide studies of methylation in children support a role for epigenetic mechanisms in asthma; however, studies in adults are rare and few have examined non-atopic asthma. We conducted the largest epigenome-wide association study (EWAS) of blood DNA methylation in adults in relation to non-atopic and atopic asthma.We measured DNA methylation in blood using the Illumina MethylationEPIC array among 2286 participants in a case-control study of current adult asthma nested within a United States agricultural cohort. Atopy was defined by serum specific immunoglobulin E (IgE). Participants were categorised as atopy without asthma (n=185), non-atopic asthma (n=673), atopic asthma (n=271), or a reference group of neither atopy nor asthma (n=1157). Analyses were conducted using logistic regression.No associations were observed with atopy without asthma. Numerous cytosine-phosphate-guanine (CpG) sites were differentially methylated in non-atopic asthma (eight at family-wise error rate (FWER) p<9×10-8, 524 at false discovery rate (FDR) less than 0.05) and implicated 382 novel genes. More CpG sites were identified in atopic asthma (181 at FWER, 1086 at FDR) and implicated 569 novel genes. 104 FDR CpG sites overlapped. 35% of CpG sites in non-atopic asthma and 91% in atopic asthma replicated in studies of whole blood, eosinophils, airway epithelium, or nasal epithelium. Implicated genes were enriched in pathways related to the nervous system or inflammation.We identified numerous, distinct differentially methylated CpG sites in non-atopic and atopic asthma. Many CpG sites from blood replicated in asthma-relevant tissues. These circulating biomarkers reflect risk and sequelae of disease, as well as implicate novel genes associated with non-atopic and atopic asthma.
    • Fate of the UPR marker protein Kar2/Bip and autophagic processes in fed-batch cultures of secretory insulin precursor producing Pichia pastoris.

      Roth, Gustavo; Vanz, Ana Letícia; Lünsdorf, Heinrich; Nimtz, Manfred; Rinas, Ursula; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018-08-09)
      Secretory recombinant protein production with Pichia (syn. Komagataella) pastoris is commonly associated with the induction of an unfolded protein response (UPR) usually apparent through increased intracellular levels of endoplasmic reticulum (ER) resident chaperones such as Kar2/Bip. During methanol-induced secretory production of an insulin precursor (IP) under industrially relevant fed-batch conditions the initially high level of intracellular Kar2/Bip after batch growth on glycerol unexpectedly declined in the following methanol fed-batch phase misleadingly suggesting that IP production had a low impact on UPR activation. Analysis of the protein production independent level of Kar2/Bip revealed that high Kar2/Bip levels were reached in the exponential growth phase of glycerol batch cultures followed by a strong decline of Kar2/Bip during entry into stationary phase. Ultra-structural cell morphology studies revealed autophagic processes (e.g. ER phagy) at the end of the glycerol batch phase most likely responsible for the degradation of ER resident chaperones such as Kar2/Bip. The pre-induction level of Kar2/Bip did not affect the IP secretion efficiency in the subsequent methanol-induced IP production phase. During growth on methanol intracellular Kar2/Bip levels declined in IP producing and non-producing host cells. However, extracellular accumulation of Kar2/Bip was observed in IP-producing cultures but not in non-producing controls. Most importantly, the majority of the extracellular Kar2/Bip accumulated in the culture supernatant of IP producing cells as truncated protein (approx. 35 kDa). Rapid growth leads to higher basal levels of the major UPR marker protein Kar2/Bip independent of recombinant protein production. Entry into stationary phase or slower growth on poorer substrate, e.g. methanol, leads to a lower basal Kar2/Bip level. Methanol-induced secretory IP production elicits a strong UPR activation which counteracts the reduced UPR during slow growth on methanol. The major ER chaperone Kar2/Bip is found together with recombinant IP in the culture medium where full-length Kar2/Bip accumulates in addition to large amounts of truncated Kar2/Bip. Thus, for judging UPR activating properties of the produced protein it is important to additionally analyze the medium not only for intact Kar2/Bip but also for truncated versions of this UPR reporter protein.
    • FKBPs in bacterial infections.

      Ünal, Can M; Steinert, Michael; Helmholtz Centre for infection research, Inhoffenstr. 7, D-38124 Braunschweig, Germany. (2015-10)
      FK506-binding proteins (FKBPs) contain a domain with peptidyl-prolyl-cis/trans-isomerase (PPIase) activity and bind the immunosuppressive drugs FK506 and rapamycin. FKBPs belong to the immunophilin family and are found in eukaryotes and bacteria.
    • Functional and immunogenic characterization of diverse HCV glycoprotein E2 variants.

      Khera, Tanvi; Behrendt, Patrick; Bankwitz, Dorothea; Brown, Richard J P; Todt, Daniel; Doepke, Mandy; Ghafoor Khan, Abdul; Schulze, Kai; Law, John; Logan, Michael; et al. (Elsevier, 2018-11-12)
      Induction of cross-reactive antibodies targeting conserved epitopes of the envelope proteins E1E2 is a key requirement for an HCV vaccine. Conserved epitopes like the viral CD81-binding site are targeted by rare broadly neutralizing antibodies. However, these viral segments are occluded by variable regions and glycans. We aimed to identify antigens exposing conserved epitopes and to characterize their immunogenicity. We created HCV variants with mutated glycosylation sites and/or hypervariable region 1 (HVR1). Exposure of the CD81 binding site and conserved epitopes was quantified by soluble CD81 and antibody interaction and neutralization assays. E2 or E1-E2 heterodimers with mutations causing epitope exposure were used to immunize mice. Vaccine-induced antibodies were examined and compared with patient-derived antibodies. Mutant viruses bound soluble CD81 and antibodies targeting the CD81 binding site with enhanced efficacy. Mice immunized with E2 or E1E2 heterodimers incorporating these modifications mounted strong, cross-binding, and non-interfering antibodies. E2-induced antibodies neutralized the autologous virus but they were not cross-neutralizing. Viruses lacking the HVR1 and selected glycosylation sites expose the CD81 binding site and cross-neutralization antibody epitopes. Recombinant E2 proteins carrying these modifications induce strong cross-binding but not cross-neutralizing antibodies.
    • Functional design of pH-responsive folate-targeted polymer-coated gold nanoparticles for drug delivery and in vivo therapy in breast cancer

      Mahalunkar, Sneha; Yadav, Amit Singh; Gorain, Mahadeo; Pawar, Vinay; Braathen, Ranveig; Weiss, Siegfried; Bogen, Bjarne; Gosavi, Suresh W.; Kundu, Gopal C.; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (2019-01-01)
      Background: Curcumin has been widely used owing to its various medicinal properties including antitumor effects. However, its clinical application is limited by its instability, poor solubility and low bioavailability. Folic acid (FA)-functionalized nanoformulations may enhance the sustained release of an anticancer drug (curcumin) by tumor-specific targeting to improve therapeutic benefit. This study aims to design a nanoconjugate (NC) comprised of folate–curcumin-loaded gold–polyvinylpyrrolidone nanoparticles (FA–CurAu-PVP NPs) for targeted delivery in breast cancer model systems. Methods: We developed curcumin-loaded FA-functionalized Au-PVP NCs by layer-by-layer assembly. The folic acid–curcumin Au-PVP NCs (FA–CurAu-PVP NCs) were characterized by ultraviolet–visible spectra, Fourier transform infrared spectroscopy, X-ray powder diffraction and thermogravimetric analysis. In vitro anticancer and antimigratory effects of NCs were examined by performing MTT and wound migration assays. The in vivo antitumor efficacy of NCs was investigated using a preclinical breast cancer orthotopic mouse model. Results: Curcumin (40 µg/mL) was loaded along with conjugation of folate onto Au-PVP NPs to form FA–CurAu-PVP NCs. The size and charge of the NCs were increased gradually through layer-by-layer assembly and showed 80% release of curcumin at acidic pH. The NC did not show aggregation when incubated with human serum and mimicked an intrinsic peroxidase-like property in the presence of 3,3ʹ,5,5ʹ-tetramethylbenzidine substrate. The MTT data using these NCs showed efficient anticancer activity at lower doses in estrogen/ progesterone receptor (ER/PR)-negative cells compared with ER/PR-positive cells. Furthermore, the NCs did not show cytotoxicity at the investigated concentration in human breast epithelial and mouse fibroblast cell lines. They showed inhibitory effects on cell migration and high antitumor efficacy in in vivo analysis. Conclusion: These results suggest that folate-based tumor targeting using CurAu-PVP NCs is a promising approach for tumor-specific therapy of breast cancer without harming normal cells.
    • Future Organization of Clinical Research in Germany: The Road to the "German Centre for Digestive Health" (GCDH).

      Manns, Michael P; Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School (MHH), Hannover, Germany. (2016-12)
    • Gain of function in Jak2V617F-positive T-cells.

      Nishanth, G; Wolleschak, D; Fahldieck, C; Fischer, T; Mullally, A; Perner, F; Schnöder, T M; Just, S; Heidel, F H; Schlüter, D; et al. (2017-04)