TWISTED DWARF1, a unique plasma membrane-anchored immunophilin-like protein, interacts with Arabidopsis multidrug resistance-like transporters AtPGP1 and AtPGP19

Null-mutations of the Arabidopsis FKBP-like immunophilin TWISTED DWARF1 (TWD1) gene cause a pleiotropic phenotype characterized by reduction of cell elongation and disorientated growth of all plant organs. Heterologously expressed TWD1 does not exhibit cis-trans-peptidylprolyl isomerase (PPIase) activity and does not complement yeast FKBP12 mutants, suggesting that TWD1 acts indirectly via protein-protein interaction. Yeast two-hybrid protein interaction screens with TWD1 identified cDNA sequences that encode the C-terminal domain of Arabidopsis multidrug-resistance-like ABC transporter AtPGP1. This interaction was verified in vitro. Mapping of protein interaction domains shows that AtPGP1 surprisingly binds to the N-terminus of TWD1 harboring the cis-trans peptidyl-prolyl isomerase-like domain and not to the tetratrico-peptide repeat domain, which has been shown to mediate protein-protein interaction. Unlike all other FKBPs, TWD1 is shown to be an integral membrane protein that colocalizes with its interacting partner AtPGP1 on the plasma membrane. TWD1 also interacts with AtPGP19 (AtMDR1), the closest homologue of AtPGP1. The single gene mutation twd1-1 and double atpgp1-1/atpgp19-1 (atmdr1-1) mutants exhibit similar phenotypes including epinastic growth, reduced inflorescence size, and reduced polar auxin transport, suggesting that a functional TWD1-AtPGP1/AtPGP19 complex is required for proper plant development.     

Identification and characterization of Leuconostoc fallax strains isolated from an industrial sauerkraut fermentation

Lactic acid bacterial strains were isolated from brines sampled after 7 days of an industrial sauerkraut fermentation, and six strains were selected on the basis of susceptibility to bacteriophages. Bacterial growth in cabbage juice was monitored, and the fermentation end products were identified, quantified, and compared to those of Leuconostoc mesenteroides. Identification by biochemical fingerprinting, endonuclease digestion of the 16S-23S intergenic transcribed spacer region, and sequencing of variable regions V1 and V2 of the 16S rRNA gene indicated that the six selected sauerkraut isolates were Leuconostoc fallax strains. Random amplification of polymorphic DNA fingerprints indicated that the strains were distinct from one another. The growth and fermentation patterns of the L. fallax isolates were highly similar to those of L. mesenteroides. The final pH of cabbage juice fermentation was 3.6, and the main fermentation end products were lactic acid, acetic acid, and mannitol for both species. However, none of the L. fallax strains exhibited the malolactic reaction, which is characteristic of most L. mesenteroides strains. These results indicated that in addition to L. mesenteroides, a variety of L. fallax strains may be present in the heterofermentative stage of sauerkraut fermentation. The microbial ecology of sauerkraut fermentation appears to be more complex than previously indicated, and the prevalence and roles of L. fallax require further investigation.     

Enzymic synthesis of glutamic acid γ-semialdehyde (Δ1-pyrroline-5-carboxylate) and N-acetyl-l-glutamic acid γ-semialdehyde: Isolation and characterization of their 2,4-dinitrophenylhydrazones

A protocol is given for the synthesis, by a simple enzyme preparation, of the l-isomers of glutamic acid γ-semialdehyde and N-acetylglutamic acid γ-semialdehyde. The isolation and physical and chemical properties of these products as the 2,4-dinitrophenylhydrazone derivatives are described. Spectral characteristics, NMR, ir, and visible, and melting points for these compounds are given.     

Safety and immunogenicity of 2-dose heterologous Ad26.ZEBOV,MVA-BN-Filo Ebola vaccination in children and adolescents in Africa: A randomised,placebo-controlled,multicentre Phase II clinical trial

BackgroundReoccurring Ebola outbreaks in West and Central Africa have led to serious illness and death in thousands of adults and children. The objective of this study was to assess safety, tolerability, and immunogenicity of the heterologous 2-dose Ad26.ZEBOV, MVA-BN-Filo vaccination regimen in adolescents and children in Africa.Methods and findingsIn this multicentre, randomised, observer-blind, placebo-controlled Phase II study, 131 adolescents (12 to 17 years old) and 132 children (4 to 11 years old) were enrolled from Eastern and Western Africa and randomised 5:1 to receive study vaccines or placebo. Vaccine groups received intramuscular injections of Ad26.ZEBOV (5 × 10¹⁰ viral particles) and MVA-BN-Filo (1 × 10⁸ infectious units) 28 or 56 days apart; placebo recipients received saline. Primary outcomes were safety and tolerability. Solicited adverse events (AEs) were recorded until 7 days after each vaccination and serious AEs (SAEs) throughout the study. Secondary and exploratory outcomes were humoral immune responses (binding and neutralising Ebola virus [EBOV] glycoprotein [GP]-specific antibodies), up to 1 year after the first dose. Enrolment began on February 26, 2016, and the date of last participant last visit was November 28, 2018. Of the 263 participants enrolled, 217 (109 adolescents, 108 children) received the 2-dose regimen, and 43 (20 adolescents, 23 children) received 2 placebo doses. Median age was 14.0 (range 11 to 17) and 7.0 (range 4 to 11) years for adolescents and children, respectively. Fifty-four percent of the adolescents and 51% of the children were male. All participants were Africans, and, although there was a slight male preponderance overall, the groups were well balanced. No vaccine-related SAEs were reported; solicited AEs were mostly mild/moderate. Twenty-one days post-MVA-BN-Filo vaccination, binding antibody responses against EBOV GP were observed in 100% of vaccinees (106 adolescents, 104 children). Geometric mean concentrations tended to be higher after the 56-day interval (adolescents 13,532 ELISA units [EU]/mL, children 17,388 EU/mL) than the 28-day interval (adolescents 6,993 EU/mL, children 8,007 EU/mL). Humoral responses persisted at least up to Day 365.A limitation of the study is that the follow-up period was limited to 365 days for the majority of the participants, and so it was not possible to determine whether immune responses persisted beyond this time period. Additionally, formal statistical comparisons were not preplanned but were only performed post hoc.ConclusionsThe heterologous 2-dose vaccination was well tolerated in African adolescents and children with no vaccine-related SAEs. All vaccinees displayed anti-EBOV GP antibodies after the 2-dose regimen, with higher responses in the 56-day interval groups. The frequency of pyrexia after vaccine or placebo was higher in children than in adolescents. These data supported the prophylactic indication against EBOV disease in a paediatric population, as licenced in the EU.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02564523","term_id":"NCT02564523"}}NCT02564523.

Zacchaeus Anywaine and co-workers study safety and immunogenicity of an Ebola vaccine among children and adolescents across four African countries.     

Efficient generation of antileukemic autologous T cells by short-term culture and γ-irradiation of myeloid leukemic cells

Blasts from patients with acute myeloid leukemia (AML) can be differentiated in dendritic cells (DCs) using appropriate combinations of cytokines. However, generation of autologous antileukemic cytotoxic T cells using leukemic DCs remains difficult. We have previously reported that expression of costimulatory molecules in cultured AML cells could be induced by -irradiation. In the present study, blasts from 21 patients with AML were cultured in vitro for 2 days, then cells were -irradiated and antigen-presenting cell (APC) characteristics were assessed. -Irradiation induced expression of several characteristics of APCs in AML blasts, including expression of CD80, CD86, and BDCA-4, and were stimulators of allogeneic mixed lymphocyte reactions. Autologous antileukemic cytotoxicity was induced in seven out of ten cases. This study shows that cells with APC characteristics and able to induce ex vivo stimulation of autologous antileukemic T cells can be generated from AML cells using the simple and rapid method of -irradiation of cultured leukemic cells.Rodolphe Vereecque and Aurore Saudemont contributed equally to this work.     

Counterfactual links to the proportion of treatment effect explained by a surrogate marker

In a randomized clinical trial, a statistic that measures the proportion of treatment effect on the primary clinical outcome that is explained by the treatment effect on a surrogate outcome is a useful concept. We investigate whether a statistic proposed to estimate this proportion can be given a causal interpretation as defined by models of counterfactual variables. For the situation of binary surrogate and outcome variables, two counterfactual models are considered, both of which include the concept of the proportion of the treatment effect, which acts through the surrogate. In general, the statistic does not equal either of the two proportions from the counterfactual models, and can be substantially different. Conditions are given for which the statistic does equal the counterfactual model proportions. A randomized clinical trial with potential surrogate endpoints is undertaken in a scientific context; this context will naturally place constraints on the parameters of the counterfactual model. We conducted a simulation experiment to investigate what impact these constraints had on the relationship between the proportion explained (PE) statistic and the counterfactual model proportions. We found that observable constraints had very little impact on the agreement between the statistic and the counterfactual model proportions, whereas unobservable constraints could lead to more agreement.     

Oxidation of Zn(N2S2) complexes to disulfonates: relevance to zinc-finger oxidation under oxidative stress

A series of Zn(N2S2) complexes has been prepared, and characterized. They have different nitrogen donors such as, either two amidates, two amines, two imines or one amidate and one imine. A bis-amidato dithiolato complex has been structurally characterized by single crystal X-ray diffraction analysis, and exhibits a distorted tetrahedral structure. Oxidation of all these complexes with dioxirane or anhydrous H2O2 results in the formation of a unique product, the disulfonate species. Most often, zinc was found to be released during the course of the oxidation. The bis-imine/bis-sulfonate species is the only one to retain zinc. This complex was crystallized with two pyridine molecules. Its crystal structure reveals a distorted octahedral environment around the zinc cation.     

Occurrence of Listeria spp. in effluents of French urban wastewater treatment plants

Listeria spp. were found in most treated waters (84.4%) and raw sludge (89.2%) of six French urban wastewater treatment plants and one composting facility, examined monthly over a 1-year period. Most strains belonged to Listeria monocytogenes, serotypes 4b/4e being predominant. Sludge composting and liming reduced or prevented Listeria contamination.