Nuclear localization and secretion competence are conserved among henipavirus matrix proteins

Authors: McLinton, Elisabeth C.; Wagstaff, Kylie M.; Lee, Alexander; Moseley, Gregory W.; Marsh, Glenn A.; Wang, Lin-Fa; Jans, David A.; Lieu, Kim G.; Netter, Hans J.

Source: JOURNAL OF GENERAL VIROLOGY, 98 (4):563-576, APR 2017

Brief summary of the paper: Viruses of the genus Henipavirus of the family Paramyxoviridae are zoonotic pathogens, which have emerged in Southeast Asia, Australia and Africa. Nipah virus (NiV) and Hendra virus are highly virulent pathogens transmitted from bats to animals and humans, while the henipavirus Cedar virus seems to be non-pathogenic in infection studies.

The full replication cycle of the Paramyxoviridae occurs in the host cell’s cytoplasm, where viral assembly is orchestrated by the matrix (M) protein. Unexpectedly, the NiV-M protein traffics through the nucleus as an essential step to engage the plasma membrane in preparation for viral budding/release.

Comparative studies were performed to assess whether M protein nuclear localization is a common feature of the henipaviruses, including the recently sequenced (although not yet isolated) Ghanaian bat henipavirus (Kumasi virus, GH-M74a virus) and Mojiang virus. Live-cell confocal microscopy revealed that nuclear translocation of GFP-fused M protein is conserved between henipaviruses in both human- and bat-derived cell lines.

However, the efficiency of M protein nuclear localization and virus-like particle budding competency varied. Additionally, Cedar virus-, Kumasi virus- and Mojiang virus-M proteins were mutated in a bipartite nuclear localization signal, indicating that a key lysine residue is essential for nuclear import, export and induction of budding events, as previously reported for NiV-M.

The results of this study suggest that the M proteins of henipaviruses may utilize a similar nucleocytoplasmic trafficking pathway as an essential step during viral replication in both humans and bats.

Interferon epsilon promotes HIV restriction at multiple steps of viral replication

Authors: Garcia-Minambres, Albert; Eid, Sahar G.; Mangan, Niamh E.; Pade, Corinna; Lim, San S.; Matthews, Antony Y.; de Weerd, Nicole A.; Hertzog, Paul J.; Mak, Johnson

Source: IMMUNOLOGY AND CELL BIOLOGY, 95 (5):478-483, MAY-JUN 2017

Brief summary of the paper: Interferon epsilon (IFNε) is a type I IFN that is expressed constitutively in the female reproductive tract (FRT), and contributes to protection in models of sexually transmitted infections.

Using multiple cell systems, including reporter cell lines and activated peripheral blood lymphocytes (PBLs), we show that recombinant IFNε impairs HIV infection at stage(s) post HIV entry and up to the translation of viral proteins. Consistent with this, IFNε upregulated a number of host cell restriction factors that block HIV at these stages of the replication cycle.

The potency of IFNε induction of these HIV restriction factors was comparable to conventional type I IFNs, namely IFNα and IFNβ. IFNε also significantly reduced the infectivity of progeny virion particles likely by inducing expression of HIV restriction factors, such as IFITM3, which act at that stage of infection. Thus, our data demonstrate that human IFNε suppresses HIV replication at multiple stages of infection.

Setting conservation priorities for migratory networks under uncertainty

Authors: Dhanjal-Adams, Kiran L.; Klaassen, Marcel; Nicol, Sam; Possingham, Hugh P.; Chades, Iadine; Fuller, Richard A.

SourceCONSERVATION BIOLOGY, 31 (3):646-656, JUN 2017

Brief summary of the paper: Conserving migratory species requires protecting connected habitat along the pathways they travel. Despite recent improvements in tracking animal movements, migratory connectivity remains poorly resolved at a population level for the vast majority of species, thus conservation prioritization is hampered.

To address this data limitation, we developed a novel approach to spatial prioritization based on a model of potential connectivity derived from empirical data on species abundance and distance traveled between sites during migration. We applied the approach to migratory shorebirds of the East Asian-Australasian Flyway.

Conservation strategies that prioritized sites based on connectivity and abundance metrics together maintained larger populations of birds than strategies that prioritized sites based only on abundance metrics. The conservation value of a site therefore depended on both its capacity to support migratory animals and its position within the migratory pathway; the loss of crucial sites led to partial or total population collapse.

We suggest that conservation approaches that prioritize sites supporting large populations of migrants should, where possible, also include data on the spatial arrangement of sites.

Purifying selection and concerted evolution of RNA-sensing toll-like receptors in migratory waders

Marcel K. and Beata U.

Authors: Nynke Raven, Simeon Lisovski, Marcel Klaassen, Nathan Lo, Thomas Madsen, Simon Y.W. Ho, Beata Ujvari

Source: Infection, Genetics and Evolution (Available online 18 May 2017)

Brief summary of the paper: Migratory birds encounter a broad range of pathogens during their journeys, making them ideal models for studying immune gene evolution. Despite the potential value of these species to immunoecology and disease epidemiology, previous studies have typically focused on their adaptive immune gene repertoires.

In this study, we examined the evolution of innate immune genes in three long-distance migratory waders (order Charadriiformes). We analysed two parts of the extracellular domains of two Toll-like receptors (TLR3 and TLR7) involved in virus recognition in the Sanderling (Calidris alba), Red-necked Stint (Calidris ruficollis), and Ruddy Turnstone (Arenaria interpres). Our analysis was extended to 50 avian species for which whole-genome sequences were available, including two additional waders.

We found that the inferred relationships among avian TLR3 and TLR7 do not match the whole-genome phylogeny of birds. Further analyses showed that although both loci are predominantly under purifying selection, the evolution of the extracellular domain of avian TLR3 has also been driven by episodic diversifying selection. TLR7 was found to be duplicated in all five wader species and in two other orders of birds, Cuculiformes and Passeriformes.

The duplication is likely to have occurred in the ancestor of each order, and the duplicated copies appear to be undergoing concerted evolution. The phylogenetic relationships of wader TLR7 matched those of the five wader species, but that of TLR3 did not. Instead, the tree inferred from TLR3 showed potential associations with the species’ ecology, including migratory behaviour and exposure to pathogens.

Our study demonstrates the importance of combining immunological and ecological knowledge to understand the impact of immune gene polymorphism on the evolutionary ecology of infectious diseases.

Exposure Risk for Infection and Lack of Human-to-Human Transmission of Mycobacterium ulcerans Disease, Australia

Daniel O. and Eugene A.

Authors: O’Brien, Daniel P.; Wynne, James W.; Buultjens, Andrew H.; Michalski, Wojtek P.; Stinear, Timothy R.; Friedman, N. Deborah; Hughes, Andrew; Athan, Eugene

Source: EMERGING INFECTIOUS DISEASES, 23 (5):837-840, MAY 2017

Brief summary of the paper: We conducted epidemiologic and genetic analyses of family clusters of Mycobacterium ulcerans (Buruli ulcer) disease in southeastern Australia. We found that the incidence of M. ulcerans disease in family members was increased. However, the risk for exposure appeared short-term and not related to human-human transmission.

Mycobacterium ulcerans is a slow-growing organism that causes necrotizing infections of skin and soft tissue, often requiring reconstructive surgery and resulting in long-term disability. Prevailing opinion is that humans are infected from the environment; insects, such as mosquitoes, and water-residing biting arthropods, have been proposed as vectors for transmission. In Victoria, Australia, there is evidence that native opossums might be involved in transmission. However, despite extensive research, the environmental reservoir of the organism and mode of transmission remain unknown.

We postulated that examination of M. ulcerans disease (Buruli ulcer) family clusters might provide useful new information about disease epidemiology. Theoretically, genetically related first-degree relatives have similar susceptibility to disease, and families share the same environment and therefore a similar exposure risk.

Thus, we examined the epidemiology of M. ulcerans disease in family clusters managed in a large prospective observational cohort from the Bellarine Peninsula in southeastern Australia. We used data collected from all confirmed M. ulcerans cases managed during January 1, 1998–April 12, 2016, at Barwon Health, a tertiary referral hospital in Geelong, Australia.

shRNAs targeting either the glycoprotein or polymerase genes inhibit Viral haemorrhagic septicaemia virus replication in zebrafish ZF4 cells

Authors: Clarke, Brian D.; McColl, Kenneth A.; Ward, Alister C.; Doran, Timothy J.

Source: ANTIVIRAL RESEARCH, 141 124-132, MAY 2017

Brief summary of the paper: Viral haemorrhagic septicaemia virus (VHSV) represents an important disease of finfish. To explore the potential of shRNAs to combat this disease nucleotide sequences of either the VHSV glycoprotein (G) or polymerase (L) gene were targeted. T

o test their function, shRNAs were expressed in zebrafish epithelial ZF-4 cells utilizing the zebrafish U6-2 promoter. Five of the six shRNA molecules successfully reduced VHSV replication by between 2 and 4 logs in titre relative to an irrelevant control shRNA at all MOIs and also reduced viral CPE at the highest MOI.

To ensure that observed reductions in viral titre were dependent on shRNA silencing, potential non-specific antiviral responses were assessed. Only the ineffective shRNA, which formed an improper hairpin when analysed in silico, induced an antiviral response as measured by induction of interferon (ifnphi1) and Mx (MxA) genes.

These results represent an important preliminary step in the generation of transgenic zebrafish resistant to VHSV.

An experimental examination of interindividual variation in feather corticosterone content in the house sparrow, Passer domesticus in southeast Australia

Authors: Aharon-Rotman, Yaara; Buchanan, Katherine L.; Klaassen, Marcel; Buttemer, William A.


Brief summary of the paper: Non-invasive techniques for measuring glucocorticoids (GCs) have become more prevalent, due to the advantage of eliminating the effects of animal disturbance on GC levels and their potential to provide an integrated, historic estimate of circulating GC levels. In the case of birds, corticosterone (CORT) is deposited in feathers, and may reflect a bird’s GC status over the period of feather synthesis.

This technique thus permits a retrospective view of the average circulating GC levels during the moult period. While it is generally assumed that differences in feather CORT content (CORTf) between individuals reflects their different stress histories during either natural or induced moult, it is not clear how much of this variation is due to extrinsic versus intrinsic factors.

We examined this question by determining CORTf in free-living house sparrows (Passer domesticus) from two populations, one urban and the other rural, that were plucked before and after exposure to different plasma CORT levels while held captive. We experimentally manipulated plasma CORT by implanting birds with either a corticosterone-filled, metyrapone-filled, or empty (‘sham’) silastic capsule as replacement feathers first emerged. The pattern of post-treatment CORTf was consistent with our expectations, based on plasma CORT levels of an experimentally implanted reference group. However, there was no statistically significant difference in CORTbetween these treatment groups unless sex, population origin, and CORTf of original feathers for each individual were included in a model.

Thus, birds with higher CORTf in feathers removed for this experiment tended to have higher CORTf in post-treatment replacement feathers, irrespective of treatment. In addition, we found that feather fault bar scores were significantly higher in CORT-treated birds than in the other two treatment groups, but did not vary directly with CORTf level.

Our study therefore broadly confirms the use of feathers as a non-invasive tool to estimate plasma CORT during moult in birds, but importantly demonstrates the potential for intrinsic differences in stress characteristics between populations and individuals to obscure the effects extrinsic stressors might have on CORTf.

Identifying and integrating patient and caregiver perspectives for clinical practice guidelines on the screening and management of infectious microorganisms in hemodialysis units

Authors: Miller, Hilary M.; Tong, Allison; Tunnicliffe, David J.; Campbell, Denise; Pinter, Jule; Commons, Robert J.; Athan, Eugene; Craig, Jonathan C.; Gilroy, Nicole; Green, Julianne; Henderson, Belinda; Howell, Martin; Stuart, Rhonda L.; van Eps, Carolyn; Wong, Muh Geot; de Zoysa, Janak; Jardine, Meg J.

Source: HEMODIALYSIS INTERNATIONAL, 21 (2):213-223, APR 2017

Brief summary of the paper:

Introduction: The integration of patient and caregiver input into guideline development can help to ensure that clinical care addresses patient expectations, priorities, and needs. We aimed to identify topics and outcomes salient to patients and caregivers for inclusion in the Kidney Health Australia Caring for Australasians with Renal Impairment (KHA-CARI) clinical practice guideline on the screening and management of infectious microorganisms in hemodialysis units.

Methods: A facilitated workshop was conducted with 11 participants (patients [n = 8], caregivers [n = 3]). Participants identified and discussed potential topics for inclusion in the guidelines, which were compared to those developed by the guideline working group. The workshop transcript was thematically analyzed to identify and describe the reasons underpinning their priorities.

Findings: Patients and caregivers identified a range of topics already covered by the scope of the proposed guidelines and also suggested additional topics: privacy and confidentiality, psychosocial care during/after disease notification, quality of transportation, psychosocial treatment of patients in isolation, patient/caregiver education and engagement, and patient advocacy. Five themes characterized discussion and underpinned their choices: shock and vulnerability, burden of isolation, fear of infection, respect for privacy and confidentiality, and confusion over procedural inconsistencies.

Discussion: Patients and caregivers emphasized the need for guidelines to address patient education and engagement, and the psychosocial implications of communication and provision of care in the context of infectious microorganisms in hemodialysis units. Integrating patient and caregiver perspectives can help to improve the relevance of guidelines to enhance quality of care, patient experiences, and health and psychosocial outcomes.

Development of an anti-ferret CD4 monoclonal antibody for the characterisation of ferret T lymphocytes

Authors: Layton, Daniel S.; Xiao, Xiaowen; Bentley, John D.; Lu, Louis; Stewart, Cameron R.; Bean, Andrew G. D.; Adams, Timothy E.


Brief summary of the paper: The ferret is an established animal model for a number of human respiratory viral infections, such as influenza virus and more recently, Ebola virus. However, a paucity of immunological reagents has hampered the study of cellular immune responses.

Here we describe the development and characterisation of a novel monoclonal antibody (mAb) against the ferret CD4 antigen and the characterisation of ferret CD4 T lymphocytes. Recombinant production and purification of the ferret CD4 ectodomain soluble protein allowed hybridoma generation and the generation of a mAb (FeCD4) showing strong binding to ferret CD4 protein and lymphoid cells by flow cytometry.

FeCD4 bound to its cognate antigen post-fixation with paraformaldehyde (PFA) which is routinely used to inactivate highly pathogenic viruses. We have also used FeCD4 in conjunction with other immune cell markers to characterise ferret T cells in both primary and secondary lymphoid organs.

In summary, we have developed an important reagent for the study of cellular immunological responses in the ferret model of infectious disease.

Association between bipolar spectrum disorder and bone health: a meta-analysis and systematic review protocol

Authors: Chandrasekaran, Vinoomika; Brennan-Olsen, Sharon L.; Stuart, Amanda L.; Pasco, Julie A.; Berk, Michael; Hodge, Jason M.; Williams, Lana J.

Source: BMJ OPEN, 7 (2), FEB 2017

Brief summary of the paper:

Introduction: Bipolar spectrum disorder is a chronic, episodic illness, associated with significant personal, social and economic burden. It is estimated to affect ∼2.4% of the population worldwide and is commonly associated with psychological and/or physiological comorbidities. Osteoporosis is one such comorbidity, a disease of bone that is asymptomatic until a fracture occurs. This systematic review attempts to capture, collate, assess and discuss the literature investigating the association between bipolar spectrum disorder and bone health.

Methods and analysis: We aim to identify articles that investigate the association between bipolar spectrum disorder and bone health in adults by systematically searching the MEDLINE, PubMed, OVID and CINAHL databases. Two independent reviewers will determine eligibility of studies according to predetermined criteria, and methodological quality will be assessed using a previously published scoring system. A meta-analysis will be conducted, and statistical methods will be used to identify and control for heterogeneity, if possible. If numerical syntheses are prevented due to statistical heterogeneity, a best evidence synthesis will be conducted to assess the level of evidence for associations between bipolar spectrum disorder and bone health.

Ethics and dissemination: Ethical permission will not be required for this systematic review since only published data will be used. This protocol will be registered with PROSPERO. Findings of the review will be published in a peer-reviewed scientific journal, and will be presented to clinical and population health audiences at national and international conferences.