Neuraminidase-Inhibiting Antibody Is a Correlate of Cross-Protection against Lethal H5N1 Influenza Virus in Ferrets Immunized with Seasonal Influenza Vaccine

In preparing for the threat of a pandemic of avian H5N1 influenza virus, we need to consider the significant delay (4 to 6 months) necessary to produce a strain-matched vaccine. As some degree of cross-reactivity between seasonal influenza vaccines and H5N1 virus has been reported, this was further explored in the ferret model to determine the targets of protective immunity. Ferrets were vaccinated with two intramuscular inoculations of trivalent inactivated split influenza vaccine or subcomponent vaccines, with and without adjuvant, and later challenged with a lethal dose of A/Vietnam/1203/2004 (H5N1) influenza virus. We confirmed that vaccination with seasonal influenza vaccine afforded partial protection against lethal H5N1 challenge and showed that use of either AlPO₄ or Iscomatrix adjuvant with the vaccine resulted in complete protection against disease and death. The protection was due exclusively to the H1N1 vaccine component, and although the hemagglutinin contributed to protection, the dominant protective response was targeted toward the neuraminidase (NA) and correlated with sialic acid cleavage-inhibiting antibody titers. Purified heterologous NA formulated with Iscomatrix adjuvant was also protective. These results suggest that adjuvanted seasonal trivalent vaccine could be used as an interim measure to decrease morbidity and mortality from H5N1 prior to the availability of a specific vaccine. The data also highlight that an inducer of cross-protective immunity is the NA, a protein whose levels are not normally monitored in vaccines and whose capacity to induce immunity in recipients is not normally assessed.     

The shift from low to high non-structural protein 1 expression in rotavirus-infected MA-104 cells

A hallmark of group/species A rotavirus (RVA) replication in MA-104 cells is the logarithmic increase in viral mRNAs that occurs four-12 h post-infection. Viral protein synthesis typically lags closely behind mRNA synthesis but continues after mRNA levels plateau. However, RVA non-structural protein 1 (NSP1) is present at very low levels throughout viral replication despite showing robust protein synthesis. NSP1 has the contrasting properties of being susceptible to proteasomal degradation, but being stabilised against proteasomal degradation by viral proteins and/or viral mRNAs. We aimed to determine the kinetics of the accumulation and intracellular distribution of NSP1 in MA-104 cells infected with rhesus rotavirus (RRV). NSP1 preferentially localises to the perinuclear region of the cytoplasm of infected cells, forming abundant granules that are heterogeneous in size. Late in infection, large NSP1 granules predominate, coincident with a shift from low to high NSP1 expression levels. Our results indicate that rotavirus NSP1 is a late viral protein in MA-104 cells infected with RRV, presumably as a result of altered protein turnover.     

Notes on the genus Amorphophallus (Araceae) – 13. Evolution of pollen ornamentation and ultrastructure in Amorphophallus and Pseudodracontium

A strict consensus tree based on chloroplast and nuclear sequences (rbcL, matK, trnL, FLint2) from 46 Amorphophallus species, two Pseudodracontium species and six outgroups is used to develop a hypothesis for the evolution of ornamentation and ectexine ultrastructure in the pollen of Amorphophallus. There are four main clades: an exclusively African, largely psilate clade (‘African clade’), an Asian, largely psilate clade (‘Asian psilate clade’) and an Asian, largely striate clade consisting of a mainly continental SE Asian clade (‘continental SE Asian striate clade’) and one centred in Malesia (‘Malesian striate clade’). Ultrastructure provides a valuable contribution towards understanding pollen ornamentation in Amorphophallus. Pollen with a thin psilate ectexine without dark granules might be plesiomorphic in Amorphophallus. Then the diverse striate type would be derived. Within both striate clades, reversals to the psilate type occur. Striate pollen with psilate caps, which is nested in the continental SE Asian striate clade, is a synapomorphy of Pseudodracontium. The fossulate type is also diverse, and its distribution in the tree indicates a polyphyletic origin. Areolate, echinate and verrucate ornamentation, occur in single species in the tree, but are found also in species not included in the molecular analysis. All three are heterogeneous and probably polyphyletic too. Reticulate, scabrate and striate/scabrate ornamentation are autapomorphies, of which the reticulate type and the striate/scabrate type may derive from psilate and striate ornamentation, respectively. Of the four main clades, the Asian psilate and African clade seem to be basal, while both striate clades might have evolved from the Asian psilate clade via a species like A. rhizomatosus. Dark granules evolved more than once, which might explain their diverse size, shape and distribution.     

The impact of non-native rainbow trout within Afro-montane streams in eastern Zimbabwe

Non-native trout species have been associated with many negative effects in receiving ecosystems. The first aim of this study was to determine the impact of non-native rainbow trout Oncorhynchus mykiss on distribution and abundance of native mountain catfish Amphilius uranoscopus within Afro-montane streams in Nyanga Mountains, eastern Zimbabwe. The second aim was to compare macro-invertebrate community responses to the presence of the trout and the catfish. We examined trout impact on catfish’s habitat associations, whereas macro-invertebrate composition was compared using open fish and fish exclosure experiments in habitats with and without trout. Trout influenced both the distribution and abundance of the catfish that occupied shallow reaches possibly to avoid predation from trout that occurred in the deeper habitats. Within trout invaded reaches, most macro-invertebrate taxa were more abundant in exclosure than open treatments. By contrast, within trout-free reaches, most macro-invertebrates either did not differ between treatments or were generally more abundant in open than exclosure treatments. This suggests that the macro-invertebrate communities responded differently within invaded and non-invaded reaches. By influencing distribution and abundance of native biota, non-native rainbow trout may have wider ecological effects, such as influencing trophic interrelationships within invaded habitats.     

Endogenous Purification Reveals GREB1 as a Key Estrogen Receptor Regulatory Factor

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Highlights? A proteomic method identifies protein-protein interaction in primary tumors ? GREB1 is the top estrogen-induced ER-interacting protein ? GREB1 is an essential ER cofactor recruited to chromatin ? GREB1 is an independent prognostic marker     

Swimming with the giant: coexistence patterns of a new redfin minnow Pseudobarbus skeltoni from a global biodiversity hot spot

Ecological niche theory predicts that coexistence is facilitated by resource partitioning mechanisms that are influenced by abiotic and biotic interactions. Alternative hypotheses suggest that under certain conditions, species may become phenotypically similar and functionally equivalent, which invokes the possibility of other mechanisms, such as habitat filtering processes. To test these hypotheses, we examined the coexistence of the giant redfin Pseudobarbus skeltoni, a newly described freshwater fish, together with its congener Pseudobabus burchelli and an anabantid Sandelia capensis by assessing their scenopoetic and bionomic patterns. We found high habitat and isotope niche overlaps between the two redfins, rendering niche partitioning a less plausible sole mechanism that drives their coexistence. By comparison, environment–trait relationships revealed differences in species–environment relationships, making habitat filtering and functional equivalence less likely alternatives. Based on P. skeltoni's high habitat niche overlap with other species, and its large isotope niche width, we inferred the likelihood of differential resource utilization at trophic level as an alternative mechanism that distinguished it from its congener. In comparison, its congener P. burchelli appeared to have a relatively small trophic niche, suggesting that its trophic niche was more conserved despite being the most abundant species. By contrast, S. capensis was distinguished by occupying a higher trophic position and by having a trophic niche that had a low probability of overlapping onto those of redfins. Therefore, trophic niche partitioning appeared to influence the coexistence between S. capensis and redfins. This study suggests that coexistence of these fishes appears to be promoted by their differences in niche adaptation mechanisms that are probably shaped by historic evolutionary and ecological processes.     

Towards a Case Definition for Devil Facial Tumour Disease: What Is It?

In the mid 1990s an emerging disease characterised by the development of proliferative lesions around the face of Tasmanian devils (Sarcophilus harrisii) was observed. A multi-disciplinary approach was adopted to define the condition. Histopathological and transmission electron microscopic examination combined with immunohistochemistry help define Devil Facial Tumour Disease (DFTD) as a neoplastic condition of cells of neuroendocrine origin. Cytogenetic analysis of neoplastic tissue revealed it to be markedly different from normal devil tissue and having a consistent karyotype across all tumours examined. Combined with evidence for Major histocompatability (MHC) gene analysis there is significant evidence to confirm the tumour is a transmissible neoplasm.     

Mechanically stimulated osteocytes reduce the bone-metastatic potential of breast cancer cells in vitro by signaling through endothelial cells

Bone metastases occur in 65% to 75% of patients with advanced breast cancer and significantly worsen their survival and quality of life. We previously showed that conditioned medium (CM) from osteocytes stimulated with oscillatory fluid flow, mimicking bone mechanical loading during routine physical activities, reduced the transendothelial migration of breast cancer cells. Endothelial cells are situated at an ideal location to mediate signals between osteocytes in the bone matrix and metastasizing cancer cells in the blood vessels. In this study, we investigated the specific effects of flow-stimulated osteocytes on the interaction between endothelial cells and breast cancer cells in vitro. We observed that CM from flow-stimulated osteocytes reduced endothelial permeability by 15% and breast cancer cell adhesion onto endothelial monolayers by 18%. The difference in adhesion was abolished with anti-intercellular adhesion molecule 1 (ICAM-1) neutralizing antibodies. Furthermore, CM from endothelial cells conditioned in CM from flow-stimulated osteocytes significantly altered the gene expression in bone-metastatic breast cancer cells, as shown by RNA sequencing. Specifically, breast cancer cell expression of matrix metallopeptidase 9 (MMP-9) was downregulated by 62%, and frizzled-4 (FZD4) by 61%, when the osteocytes were stimulated with flow. The invasion of these breast cancer cells across Matrigel was also reduced by 47%, and this difference was abolished by MMP-9 inhibitors. In conclusion, we demonstrated that flow-stimulated osteocytes downregulate the bone-metastatic potential of breast cancer cells by signaling through endothelial cells. This provides insights into the capability of bone mechanical regulation in preventing bone metastases; and may assist in prescribing exercise or bone-loading regimens to patients with breast cancers.     

A model of reversible inhibitors in the gastric H+/K+-ATPase binding site determined by rotational echo double resonance NMR

Several close analogues of the noncovalent H(+)/K(+)-ATPase inhibitor SCH28080 (2-methyl-3-cyanomethyl-8-(phenylmethoxy)imidazo[1,2-a]pyridine) have been screened for activity and examined in the pharmacological site of action by solid-state NMR spectroscopy. TMPIP, the 1,2,3-trimethyl analogue of SCH28080, and variants of TMPIP containing fluorine in the phenylmethoxy ring exhibited IC(50) values for porcine H(+)/K(+)-ATPase inhibition falling in the sub-10 microm range. Deuterium NMR spectra of a (2)H-labeled inhibitor titrated into H(+)/K(+)-ATPase membranes revealed that 80-100% of inhibitor was bound to the protein, and K(+)-competition (2)H NMR experiments confirmed that the inhibitor lay within the active site. The active binding conformation of the pentafluorophenylmethoxy analogue of TMPIP was determined from (13)C-(19)F dipolar coupling measurements using the cross-polarization magic angle spinning NMR method, REDOR. It was found that the inhibitor adopts an energetically favorable extended conformation falling between fully planar and partially bowed extremes. These findings allowed a model to be proposed for the binding of this inhibitor to H(+)/K(+)-ATPase based on the results of independent site-directed mutagenesis studies. In the model, the partially bowed inhibitor interacts with Phe(126) close to the N-terminal membrane spanning helix M1 and residues in the extracellular loop bridging membrane helices M5 and M6 and is flanked by residues in M4.