Recent Results
Update: 21.09.2017

2016 - 2017


Cross, M. , Rajan, S. Biberacher, S. Park, S.-Y., Coster, M.J., Długosz, E., Kim, J.-S., Gasser, R.B., Hofmann, A. (2017) Em. Topics Life Sci., in press
Abstract
As opposed to organism-based drug screening approaches, protein-based strategies have the distinct advantage of providing insights into the molecular mechanisms of chemical effectors and thus afford a precise targeting. Capitalising on the increasing number of genome and transcriptome datasets, novel targets in pathogens for therapeutic intervention can be identified in a more rational manner as compared to conventional organism-based methodologies. Trehalose-6-phosphate phosphatases (TPPs) are structurally and functionally conserved enzymes of the trehalose biosynthesis pathway which play a critical role for pathogen survival, in particular in parasites. The absence of these enzymes as well as trehalose biosynthesis from mammalian hosts has recently given rise to increasing interest in TPPs as novel therapeutic targets for drugs and vaccines. Here, we summarise some key aspects of the current state of research towards novel therapeutics targeting in particular nematode TPPs.

Ma, G., Holland, C., Wang, T., Hofmann, A., Fan, C.-K., Maizels, R., Hotez, P.J., Gasser, R.B. (2017) Lancet Infect. Dis., in press
Abstract
Parasitic nematodes of the genus Toxocara are socioeconomically important zoonotic pathogens. These parasites are usually directly transmitted to the human host via the faecal-oral route and can cause substantial clinical disease, known as toxocariasis, as well as associated complications including allergic and/or neurological disorders. Although it is estimated that tens of million people are exposed to or infected with Toxocara species, there is limited precise epidemiological information on the relationship between seropositivity and associated disease (toxocariasis) on a global scale. Some recent studies indicate that toxocariasis is having an increased human-health impact in some countries. To gain improved insights into human toxocariasis, this seminar reviews salient background on Toxocara and biology, summarises key aspects of the pathogenesis, diagnosis and treatment of toxocariasis, describes what is presently known about its geographic distribution and prevalence, and makes some recommendations regarding future research towards the prevention and control of this important disease.
PubMed | DOI |

Preston, S., Jiao, Y., Baell, J.B., Keiser, J., Crawford, S., Koehler, A.V., Wang, T., Simpson, M.M., Kaplan, R.M., Cowley, K.J., Simpson, K.J., Hofmann, A., Jabbar, A., Gasser, R.B. (2017) Int. J. Parasitol. Drug 7, 286-294
Abstract
The discovery and development of novel anthelmintic classes is essential to sustain the control of socioeconomically important parasitic worms of humans and animals. With the aim of offering novel, lead-like scaffolds for drug discovery, Compounds Australia released the ‘Open Scaffolds’ collection containing 33,999 compounds, with extensive information available on the physicochemical properties of these chemicals. In the present study, we screened 14,464 prioritised compounds from the ‘Open Scaffolds’ collection against the exsheathed third-stage larvae (xL3s) of Haemonchus contortus using recently developed whole-organism screening assay. We identified a hit compound, called SN00797439, which was shown to reproducibly reduce xL3 motility by ≥70%; this compound induced a characteristic, “coiled” xL3 phenotype (IC50 = 3.46-5.93 μM), inhibited motility of fourth-stage larvae (L4s; IC50 = 0.31-12.5 μM) and caused considerable cuticular damage to L4s in vitro. When tested on other parasitic nematodes in vitro, SN00797439 was shown to inhibit (IC50 = 3-50 μM) adults of Ancylostoma ceylanicum (hookworm) and first-stage larvae of Trichuris muris (whipworm) and eventually kill (>90%) these stages. Furthermore, this compound completely inhibited the motility of female and male adults of Brugia malayi (50-100 μM) as well as microfilariae of both B. malayi and Dirofilaria immitis (heartworm). Overall, these results show that SN00797439 acts against genetically (evolutionarily) distant parasitic nematodes (i.e. H. contortus and A. ceylanicum [strongyloids] vs. B. malayi and D. immitis [filarioids] vs. T. muris [enoplid], and, thus, might offer a novel, lead-like scaffold for the development of a relatively broad-spectrum anthelmintic. Our future work will focus on assessing the activity of SN00797439 against other pathogens that cause neglected tropical diseases, optimising analogs with improved biological activities and characterising their targets.
PubMed | DOI |

Wibowo, M., Wang, Q., Holst, J., White, J.M., Hofmann, A., Davis, R. (2017) J. Nat. Prod. 80, 1918-1925
Abstract
Seven new dihydro-β-agarofurans, celastrofurans A–G (1–7) along with two known secondary metabolites, 9β-benzoyloxy-1α-furoyloxydihydro-β-agarofuran (8) and (1R,2R,4R,5S,7R,9S,10R)-2-acetoxy-9-benzoyloxy-1-furoyloxydihydro-β-agarofuran (9) were obtained from the leaves of the Australian rainforest vine, Celastrus subspicata. The structures of the new compounds were determined by detailed spectroscopic (1D/2D NMR and MS) data analysis. The absolute configurations of compounds 1–4 were defined by ECD and single-crystal X-ray diffraction studies. All compounds were found to exhibit inhibitory activity on leucine transport in the human prostate cancer cell line LNCaP with IC50 values ranging from 7.0–98.9 μM. Dihydro-β-agarofurans 1–9 showed better potency than the L-type amino acid transporter (LAT) family inhibitor, 2-aminobicyclo[2.2.1]-heptane-2-carboxylic acid (BCH).
PubMed | DOI |

Jiao, Y., Preston, S., Song, H., Jabbar, A., Liu, Y., Baell, J., Hofmann, A., Hutchinson, D., Wang, T., Koehler, A., Fisher, G., Andrews, K., Willis, P., Palmer, M., Wells, T., Wang, Q., Gasser, R.B. (2017) Parasites & Vectors 10, 272
Abstract
In this study, we tested five series of pyrazole-5-carboxamide compounds (n = 55) for activity against parasitic stages of the nematode Haemonchus contortus (barber’s pole worm). In an optimised, whole-organism screening assay, using exsheathed third-stage (xL3) and fourth-stage (L4) larvae, we measured the inhibition of larval motility and development of H. contortus. Amongst the 55 compounds, we identified two compounds (designated a-15 and a-17) that reproducibly inhibit xL3 motility as well as L4 motility and development, with IC50 values ranging between ~ 3.4 and 55.6 μM. We studied the effect of these two ‘hit’ compounds on mitochondrial function by measuring oxygen consumption. This assessment showed that xL3s exposed to each of these compounds consumed significantly less oxygen and had less mitochondrial activity than untreated xL3s, which was consistent with specific inhibition of complex I of the respiratory electron transport chain in arthropods. The present findings provide a sound basis for future work aiming to identify the targets of compounds a-15 and a-17, and to establish the modes of action of these chemicals in H. contortus.
PubMed | DOI |

Dallaston, M.A., Rajan, S., Chekaiban, J., Wibowo, M., Cross, M., Coster, M.J., Davis, R.A., Hofmann, A. (2017) MedChemComm 8, 1318-1321
Abstract
The soluble mycobacterial carbonic anhydrases Rv3588c and Rv1284 belong to a different class of carbonic anhydrases than those found in humans, making them attractive drug targets by using the inherent differences in the folds of the different classes. By screening a natural product library, we identified naphthoquinone derivatives as a novel non-classical inhibitor scaffold of mycobacterial carbonic anhydrases that lack the sulfonamide/sulfamate group and thus did not affect human carbonic anhydrase II.
DOI |

Türk, M., Schröder, R., Khuller, K., Hofmann, A., Berwanger, C., Ludolph, A.C., Dekomien, G., Müller, K., Weishaupt, J.H., Thiel, C.T., Clemen, C. (2017) Neurobiol. Aging 56, 213.e1-213.e5
Abstract
Mutations of the human VCP and WASH complex genes cause motor neuron and cognitive impairment disorders. Here, we analyzed a cohort of German patients with sporadic amyotrophic lateral sclerosis and frontotemporal lobar degeneration co-morbidity (ALS/FTD) for VCP and WASH complex gene mutations. Next generation panel sequencing of VCP, WASH1, FAM21C, CCDC53, SWIP, strumpellin, CAPZA1 and CAPZB genes was performed in 43 sporadic ALS/FTD patients. Subsequent analyses included Sanger sequencing, in silico analyses, real-time PCR, and CCDC53 immunoblotting. We identified one patient with the heterozygous variant c.26C>T in CAPZA1 and a second with the heterozygous variant c.2T>C in CCDC53. In silico analysis predicted structural changes in the N-terminus of CAPZα1, which may interfere with the CAPZα:CAPZβ dimerization. Though the translation initiation codon of CCDC53 is mutated, real-time PCR and immunoblotting did neither reveal any evidence for a CCDC53 haploinsufficiency nor for aberrant CCDC53 protein species. Thus, with exception of a putatively pathogenic heterozygous c.26C>T CAPZA1 mutation, our genetic analysis did not reveal mutations in VCP and the remaining WASH complex subunits.
PubMed | DOI |

Cross, M., Rajan, S., Chekaiban, J., Saunders, J., Hamilton, C., Kim, J.-S., Coster, M. J., Gasser, R. B., Hofmann, A. (2017) Sci. Rep. 7, 2015
Abstract
Owing to the key role of trehalose in pathogenic organisms, there has recently been growing interest in trehalose metabolism for therapeutic purposes. Trehalose-6-phosphate phosphatase (TPP) is a key enzyme in the most prominent biosynthesis pathway (OtsAB). Here, we compare the enzyme characteristics of recombinant TPPs from five important nematode and bacterial pathogens, including three novel members of this protein family. Analysis of the kinetics of trehalose-6-phosphate hydrolysis reveals that all five enzymes display a burst-like kinetic behaviour which is characterised by a decrease of the enzymatic rate after the pre-steady state. The observed super-stoichiometric burst amplitudes can be explained by multiple global conformational changes by members of this enzyme family during substrate processing. In the search for specific TPP inhibitors, the trapping of the complex conformational transitions in TPPs during the catalytic cycle may present a worthwhile strategy to explore.
PubMed | DOI | Publisher |

Cross, M., Lepage, R., Rajan, S., Biberacher, S., Young, N.D., Kim, B.-N., Coster, M.J., Gasser, R.B., Kim, J.-S., Hofmann, A. (2017) FASEB J. 31, 920-926
Abstract
The trehalose biosynthetic pathway is of great interest for the development of novel therapeutics, since trehalose is an essential disaccharide in many pathogens, but neither is required nor synthesised in mammalian hosts. As such, trehalose-6-phosphate phosphatase (TPP), a key enzyme in trehalose biosynthesis is likely an attractive target for novel chemotherapeutics. Based on a survey of genomes from a panel of parasitic nematodes and bacterial organisms, and by way of a structure-based amino acid sequence alignment, we derive the topological structure of mono-enzyme trehalose-6-phosphate phosphatases and classify them into three groups. Comparison of the functional roles of amino acid residues located in the active site for TPPs belonging to different groups reveal nuanced variation. Since current literature on this enzyme family shows a tendency to infer functional roles for individual amino acid residues, we investigated the roles of the strictly conserved aspartate tetrad in TPP of the nematode Brugia malayi by using a conservative mutation approach. In contrast to aspartate-213, the residue inferred to carry out the nucleophilic attack on the substrate, we found that aspartate-215 and aspartate-428 of BmTPP are involved in the chemistry steps of enzymatic hydrolysis of the substrate. Therefore, we suggest that homology-based inference of functionally important amino acids by sequence comparison for mono-enzyme TPPs should only be carried out for each of the three groups.
PubMed | DOI |

Kim, B.-N., Shin, M., Ha, S.C., Park, S.Y., Seo, P.-W., Hofmann, A., Kim, J.-S. (2017) Sci. Rep., in press
Abstract
Activating signal cointegrator-1 homology (ASCH) domains were initially reported in human as a part of the ASC-1 transcriptional regulator, a component of a putative RNA-interacting protein complex; their presence has now been confirmed in a wide range of organisms. Here, we have determined the trigonal and monoclinic crystal structures of an ASCH domain-containing protein from Zymomonas mobilis (ZmASCH), and analyzed the structural determinants of its nucleic acid processing activity. The protein has a central β-barrel structure with several nearby α-helices. Positively charged surface patches form a cleft that runs through the pocket formed between the β-barrel and the surrounding α-helices. We further demonstrate by means of in vitro assays that ZmASCH binds nucleic acids, and degrades single-stranded RNAs in a magnesium ion-dependent manner with a cleavage preference for the phosphodiester bond between the pyrimidine and adenine nucleotides. ZmASCH also removes a nucleotide at the 5’-end. Mutagenesis studies, guided by molecular dynamics simulations, confirmed that three residues (Tyr47, Lys53, and Ser128) situated in the cleft contribute to nucleic acid-binding and RNA cleavage activities. These structural and biochemical studies imply that prokaryotic ASCH may function to control the cellular RNA amount.

Dilrukshi Herath, H.M.P., Preston, S., Hofmann, A., Davis, R.A., Koehler, A.V., Chang, B.B.-C., Jabbar, A., Gasser, R.B. (2017) Vet. Parasitol. 244, 172-175
Abstract
The control of parasitic roundworms (nematodes) is heavily reliant on the use of a limited number of anthelmintic drugs. However, drug resistance is now very widespread and no vaccines are available, such that the discovery of new chemical entities is crucial. Within this context, we screened a library of pure natural products (n = 400) against exsheathed third-stage (xL3) larvae of the parasitic nematode Haemonchus contortus using a whole-organism screening method. We identified two plant-derived rotenoids, namely deguelin and rotenone, with inhibitory activity on xL3 motility. Whereas rotenone was not investigated further because of its toxicity to mammals/vertebrates, dose response and cytotoxicity studies of deguelin showed potent and selective inhibitory activity on motility of xL3 larvae of H. contortus. Detailed future work needs to be conducted to explore the mode of action of this compound on H. contortus and related nematodes and to assess its potential as an anthelmintic candidate.
PubMed | DOI |

Preston, S., Korhonen, P.K., Mouchiroud, L., Cornaglia, M., McGee, S.L., Young, N.D., Davis, R.A., Crawford, S., Nowell, C., Ansell, B.R.E., Fisher, G.M., Andrews, K.T., Chang, B., Gijs, M.A.M., Sternberg, P.W., Auwerx, J., Baell, J., Hofmann, A., Jabbar, A., Gasser, R.B. (2017) FASEB J., in press
Abstract
As a result of limited classes of anthelmintics and an over-reliance on chemical control, there is a great need to discover new compounds to combat drug resistance in parasitic nematodes. Here, we show that deguelin, a plant-derived rotenoid, selectively and potently inhibits the motility and development of nematodes, which supports its potential as a lead candidate for drug development. Furthermore, we demonstrate that deguelin treatment significantly increases gene transcription that is associated with energy metabolism, particularly oxidative phosphorylation and mito-ribosomal protein production before inhibiting motility. Mitochondrial tracking confirmed enhanced oxidative phosphorylation. In accordance, real-time measurements of oxidative phosphorylation in response to deguelin treatment demonstrated an immediate decrease in oxygen consumption in both parasitic (Haemonchus contortus) and free-living (Caenorhabditis elegans) nematodes. Consequently, we hypothesize that deguelin is exerting its toxic effect on nematodes as a modulator of oxidative phosphorylation. This study highlights the dynamic biologic response of multicellular organisms to deguelin perturbation.
PubMed | DOI |

Cross, M., Klepzig, E., Dallaston, M., Young, N.D., Bailey, U.-M., Mason, L., Jones, M.K., Gasser, R.B., Hofmann, A. (2016) Postepy Biochemii 62, 370-376
Abstract
Despite the massive disease burden worldwide caused by parasitic nematodes and other infectious pathogens, the molecular basis of many infectious diseases caused by these pathogens has been unduly neglected for a long time. Therefore, accelerated progress towards novel therapeutics, and ultimately control of such infectious diseases, is of crucial importance. Capitalising on the wealth of data becoming available from proteomic and genomic studies, new protein targets at the pathogen-host interface can be identified and subjected to protein-based explorations of the molecular basis of pathogen-host interactions. By combining the use of systems and structural biology methodologies, insights into the structural and molecular mechanisms of these interactions can assist in the development of therapeutics and/or vaccines. This brief review examines two protein systems from the body wall of blood flukes — annexins and the stress-induced phosphoprotein 1 — both of which are presently interesting targets for the development of therapeutics.
PubMed | Publisher

Mohandas, N., Young, N.D., Abdul, J., Korhonen, P.K., Koehler, A.V., Hall, R.S., Hu, M., Hofmann, A., Gasser, R.B. (2016) Biotechnol. Advances 34, 65-76
Abstract
Although substantial research has been focused on the 'hidden antigen' H11 of Haemonchus contortus as a vaccine against haemonchosis in small ruminants, little is know about this and related aminopeptidases. In the present article, we reviewed genomic and transcriptomic data sets to define, for the first time, the complement of aminopeptidases (designated Hc-AP-1 to Hc-AP-13) of the family M1 with homologs in C. elegans, characterised by zinc-binding (HEXXH) and exo-peptidase (GAMEN) motifs. The three previously published H11 isoforms (accession nos. X94187, FJ481146 and AJ249941) had most sequence similarity to Hc-AP-2 and Hc-AP-8, whereas unpublished isoforms (accession nos. AJ249942 and AJ311316) were both most similar to Hc-AP-3. The aminopeptidases characterised here had homologs in C. elegans. Hc-AP-1 to Hc-AP-8 were most similar in amino acid sequence (28-41%) to C. elegans T07F10.1; Hc-AP-9 and Hc-AP-10 to C. elegans PAM-1 (isoform b) (53-54% similar); Hc-AP-11 and Hc-AP-12 to C. elegans AC3.5 and Y67D8C.9 (26% and 50% similar, respectively); and Hc-AP-13 to C. elegans C42C1.11 and ZC416.6 (50-58% similar). Comparative analysis suggested that Hc-AP-1 to Hc-AP-8 play roles in digestion, metabolite excretion, neuropeptide processing and/or osmotic regulation, with Hc-AP-4 and Hc-AP-7 having male-specific functional roles. The analysis also indicated that Hc-AP-9 and Hc-AP-10 might be involved in the degradation of cyclin (B3) and required to complete meiosis. Hc-AP-11 represents a leucyl/cystinyl aminopeptidase, predicted to have metallopeptidase and zinc ion binding activity, whereas Hc-AP-12 likely encodes an aminopeptidase Q homolog also with these activities and a possible role in gonad function. Finally, Hc-AP-13 is predicted to encode an aminopeptidase AP-1 homolog of C. elegans with hydrolase activity, suggested to operate, possibly synergistically with a PEPT-1 ortholog, as an oligopeptide transporter in the gut for protein uptake and normal development and/or reproduction of the worm. Appraisal of structure-based amino acid sequence alignments revealed that all conceptually translated Hc-AP proteins, with the exception of Hc-AP-12, adopt a topology similar to those observed with the two subgroups of mammalian M1 aminopeptidases which possess either three (I, II and IV) or four (I-IV) domains. In contrast, Hc-AP-12 lacks the N-terminal domain (I), but possesses a substantially expanded domain III. Although further work needs to be done to assess amino acid sequence conservation of the different aminopeptidases among individual worms within and among H. contortus populations, we hope that these insights will support future localisation, structural and functional studies of these molecules in H. contortus as well as facilitate future assessments of a recombinant subunit or cocktail vaccine against haemonchosis.
PubMed | DOI |

Wibowo, M., Wang, Q., Holst, J., White, J.M., Hofmann, A., Davis, R. (2016) Asian J. Org. Chem. 5, 1461-1466
Abstract
Two previously unknown dihydro-β-agarofuran sesquiterpenoids, denhaminol I (1) and denhaminol J (2), together with four related and known metabolites, 1α,2α,6β,15-tetraacetoxy-9α-benzoyloxy-8-oxodihydro-β-agarofuran (3), wilforsinine F (4), 1α,2α,6β,8α,15-pentaacetoxy-9α-benzoyloxydihydro-β-agarofuran (5), and 1α,2α,6β,15-tetraacetoxy-9β-benzoyloxydihydro-β-agarofuran (6), were isolated from the leaves of the Australian rainforest plant, Denhamia pittosporoides. The structures of 1 and 2 were determined by analysis of 1D/2D NMR and MS data. The absolute configuration of 1 was established by a single-crystal X-ray diffraction experiment. Compounds 1 and 4 were shown to inhibit leucine transport in the human prostate cancer cell line, LNCaP with IC50 values of 51.5 and 95.5 μM, respectively. Both 1 and 4 were more potent than the L-type amino acid transporter (LAT) family inhibitor, 2-aminobicyclo[2.2.1]-heptane-2-carboxylic acid (BCH). This is the first report of dihydro-β-agarofurans from D. pittosporoides.
DOI |

Ströhlein, A.J., Young, N.D., Hall, R.S., Korhonen, P.K., Hofmann, A., Sternberg, P.W., Jabbar, A., Gasser, R.B. (2016) Parasites & Vectors 9, 360
Abstract
Proteins of the cysteine-rich secretory proteins, antigen 5 and pathogenesis-related 1 (CAP) superfamily are recognized or proposed to play roles in parasite development and reproduction, and in modulating host immune attack and infection processes. However, little is known about these proteins for most parasites. In the present study, we explored CAP proteins of Toxocara canis, a socioeconomically important zoonotic roundworm. To do this, we mined and curated transcriptomic and genomic data, predicted and curated full-length protein sequences (n = 28), conducted analyses of these data and studied the transcription of respective genes in different developmental stages of T. canis. In addition, based on information available for C. elegans, we inferred that selected genes (including lon-1, vap-1, vap-2, scl-1, scl-8 and scl-11 orthologs) of T. canis and their interaction partners likely play central roles in this parasite's development and/or reproduction via TGF-beta and/or insulin-like signaling pathways, or via host interactions. In conclusion, this study could provide a foundation to guide future studies of CAP proteins of T. canis and related parasites, and might assist in finding new interventions against diseases caused by these parasites.
PubMed | DOI |

Preston, S., Luo, J., Zhang, Y., Jabbar, A., Crawford, S., Baell, J., Hofmann, A., Hu, M., Zhou, H.-B., Gasser, R.B. (2016) Parasites & Vectors 9, 346
Abstract
Parasitic worms represent a substantial disease burden in animals and humans worldwide. The control of parasitic roundworms (nematodes) relies heavily on the use of anthelmintic drugs. However, widespread drug resistance in nematodes seriously compromises the effectiveness of many anthelmintics around the world. Thus, there is a need to discover new drugs, with unique modes of action, to parasites. Here, we synthesized and tested 74 selenophene and thiophene-core SERMs for activity on Haemonchus contortus (barber's pole worm), one of the most important nematode pathogens of small ruminant livestock (sheep and goats) and a key representative of one of the largest groups of parasitic nematodes of animals. We identified three SERMs (one selenophene and two thiophene-core compounds) with potent inhibitory activities (at 3-25 µM) on the motility and development of parasitic stages of H. contortus. The potency of these compounds compared favourably with commercially available anthelmintics, such that they warrant further evaluation as nematocides. Further studies should focus on assessing the selectivity of these SERMs to parasites, characterising their target(s) and/or designing analogs that are parasite-specific.
PubMed | DOI |

McNeilly, C., Cosh, S., Vu, T., Nichols, J., Henningham, A., Hofmann, A., Fane, A., Smeesters, P.R., Rush, C.M., Hafner, L.M., Ketheesan, N., Sriprakash, K.S., McMillan, D.J. (2016) PLoS ONE 11, e0156639
Abstract
The C-terminal region of the M-protein of Streptococcus pyogenes is a major target for vaccine development. The major feature is the C-repeat region, consisting of 35-42 amino acid repeat units that display high but not perfect identity. SV1 is a S. pyogenes vaccine candidate that incorporates five 14mer amino acid sequences (called J14i variants) from differing C-repeat units in a single recombinant construct. Here we show that the J14i variants chosen for inclusion in SV1 are the most common variants in a dataset of 176 unique M-proteins. Murine antibodies raised against SV1 were shown to bind to each of the J14i variants present in SV1, as well as variants not present in the vaccine. Antibodies raised to the individual J14i variants were also shown to bind to multiple but different combinations of J14i variants, supporting the underlying rationale for the design of SV1. A Lewis Rat Model of valvulitis was then used to assess the capacity of SV1 to induce deleterious immune response associated with rheumatic heart disease. In this model, both SV1 and the M5 positive control protein were immunogenic. Neither of these antibodies were cross-reactive with cardiac myosin or collagen. Splenic T cells from SV1/CFA and SV1/alum immunized rats did not proliferate in response to cardiac myosin or collagen. Subsequent histological examination of heart tissue showed that 4 of 5 mice from the M5/CFA group had valvulitis and inflammatory cell infiltration into valvular tissue, whereas mice immunised with SV1/CFA, SV1/alum showed no sign of valvulitis. These results suggest that SV1 is a safe vaccine candidate that will elicit antibodies that recognise the vast majority of circulating GAS M-types.
PubMed | DOI |

Wibowo, M., Levrier, C., Sadowski, M.C., Nelson, C.C., Wang, Q., Holst, J., Healy, P.C., Hofmann, A., Davis, R.A. (2016) J. Nat. Prod. 79, 1445-1453
Abstract
Chemical investigations of the CH2Cl2 extract obtained from the leaves of the Australian rainforest tree Maytenus bilocularis afforded three new dihydro-β-agarofurans, bilocularins A-C, and six known congeners that included celastrine A, 1α,6β,8α-triacetoxy-9α-benzoyloxydihydro-β-agarofuran, 1α,6β-diacetoxy-9α-benzoyloxy-8α-hydroxydihydro-β-agarofuran, Ejap-10, 1α,6β-diacetoxy-9β-benzoyloxydihydro-β-agarofuran, and Ejap-2. The major compound bilocularin A was used in semi-synthetic studies to afford four ester derivatives. The chemical structures of bilocularins A-C were elucidated following analysis of 1D/2D NMR and MS data. The absolute configurations of bilocularins A and B were determined by single crystal X-ray crystallography. All compounds were evaluated for cytotoxic activity against the human prostate cancer cell line LNCaP; none of the compounds were active. However, several compounds showed similar potency as the drug efflux pump inhibitor verapamil in reversing the drug resistance of the human leukemia VCR R cell line. In addition, similar to verapamil, compound 5 (IC50 = 15.5 μM) was found to inhibit leucine uptake in LNCaP cells, which was more potent than the leucine analog 2-aminobicyclo[2,2,1]heptane-2-carbocyclic acid (BCH). This is the first report of secondary metabolites from Maytenus bilocularis.
PubMed | DOI |

Rijal, R., Arhzaouy, K., Strucksberg, K.-H., Cross, M., Hofmann, A., Schröder, R., Clemen, C.S., Eichinger, L. (2016) Eur. J. Cell Biol. 95, 195-207
Abstract
p97 (VCP) is a homo-hexameric triple-A ATPase that exerts a plethora of cellular processes. Heterozygous missense mutations of p97 cause at least five human neurodegenerative disorders. However, the specific molecular consequences of p97 mutations are hitherto widely unknown. Our in silico structural models of human and Dictyostelium p97 revealed that the disease-causing R93C, R155H, and R155C as well as R154C, E219K, R154C/E219K mutations of human and Dictyostelium p97, respectively, are at surface-exposed locations. In-gel p97 ATPase activity measurements of p97 monomers and hexamers revealed significant mutation- and species-specific differences. In addition, we demonstrated for the first time an intrinsic ATPase activity of p97 monomers. While all human p97 mutations led to an increase in ATPase activity, no changes could be detected for the Dictyostelium R154C mutant, which is orthologous to human R155C. The E219K mutation led to an almost complete loss of activity, which was partially recuperated in the R154C/E219K double-mutant indicating p97 inter-domain communication. By means of co-immunoprecipitation experiments, we identified a UBX-domain containing Dictyostelium protein as a novel p97 interaction partner, and, after categorizing all UBX-domain containing Dictyostelium proteins, named the interaction partner UBXD9. Pull-down assays and surface plasmon resonance analyses of Dictyostelium UBXD9 or the human ortholog TUG/ASPL/UBXD9 demonstrated direct interactions with p97 as well as species-, mutation- and ATP-dependent differences in the binding affinities. Sucrose density gradients revealed that both human and Dictyostelium UBXD9 proteins very efficiently disassembled wild-type, but to a lesser extent mutant p97 hexamers into monomers. Our results are consistent with a scenario in which p97 point mutations lead to only small differences in enzymatic activities and molecular interactions, but elicit late-onset and progressive multisystem disease.
PubMed | DOI |

Korhonen, P.K., Pozio, E., La Rosa, G., Chang, B., Koehler, A.V., Hoberg, E.P., Boag, P.R., Tan, P., Jex, A.R., Hofmann, A., Sternberg, P.W., Young, N.D., Gasser, R.B. (2016) Nat. Commun. 7, 10513
Abstract
Trichinellosis is a globally important food-borne parasitic disease of humans caused by roundworms of the Trichinella complex. Extensive biological diversity is reflected in substantial ecological and genetic variability within and among Trichinella taxa, and major controversy surrounds the systematics of this complex. Here we report the sequencing and assembly of 16 draft genomes representing all 12 recognized Trichinella species and genotypes, define protein-coding gene sets and assess genetic differences among these taxa. Using thousands of shared single-copy orthologous gene sequences, we fully reconstruct, for the first time, a phylogeny and biogeography for the Trichinella complex, and show that encapsulated and non-encapsulated Trichinella taxa diverged from their most recent common ancestor ~21 million years ago (mya), with taxon diversifications commencing ~10-7 mya.
PubMed | DOI |

Preston, S., Jabbar, A., Nowell, C., Joachim, A., Ruttkowski, B., Cardno, T., Hofmann, A., Gasser, R.B. (2016) Mol. Cell. Probes 30, 13-17
Abstract
Here, we provide a step-by-step protocol for a practical and low cost whole-organism assay for the screening of chemical compounds for activity against parasitic worms. This assay has considerable advantages over conventional methods, mainly in relation to ease of use, throughput, time and cost. It is readily suited to the screening of hundreds to thousands of compounds for subsequent hit-to-lead optimisation, and should be applicable to many different parasites and other organisms commensurate with the size of wells in the microtiter plates used for phenotypic screening.
PubMed | DOI |