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Francisella tularensis, the causative agent of tularemia, is classified as Tier 1 Select Agent with bioterrorism potential. The efficacy of the only available vaccine, LVS, is uncertain and it is not licensed in the U.S. Previously, by using an approach generally applicable to intracellular pathogens, we identified working correlates that predict successful vaccination in rodents. Here, we applied these correlates to evaluate a panel of SchuS4-derived live attenuated vaccines, namely SchuS4-ΔclpB, ΔclpB-ΔfupA, ΔclpB-ΔcapB, and ΔclpB-ΔwbtC. We combined in vitro co-cultures to quantify rodent T-cell functions and multivariate regression analyses to predict relative vaccine strength. The predictions were tested by rat vaccination and challenge studies, which demonstrated a clear relationship between the hierarchy of in vitro measurements and in vivo vaccine protection. Thus, these studies demonstrated the potential power a panel of correlates to screen and predict the efficacy of Francisella vaccine candidates, and in vivo studies in Fischer 344 rats confirmed that SchuS4-ΔclpB and ΔclpB-ΔcapB may be better vaccine candidates than LVS. [ABSTRACT FROM AUTHOR]

To understand how environmental conditions and reproductive events affect coral energetic status, seasonal variations in lipid and fatty acid profiles of the common scleractinian coral, Acropora millepora, were studied from pre-spawning in November 2009 until post-spawning in November 2010 at Halfway Island (in the Keppel Island Group, Southern Great Barrier Reef, Australia). Seasonal chlorophyll levels, photosynthetically active radiation (PAR), rainfall and water temperature were major drivers of the overall coral lipid profile, and this was particularly pronounced in correlations with the important, high-energy lipid, triacylglycerol. This likely reflected changing food sources and feeding modes (i.e. phototrophy vs heterotrophy), which corresponds to the opportunistic feeding behaviour of corals. Water temperature was also a major influencer of the coral fatty acid profile. In particular, saturated fatty acids correlated positively with water temperature, while polyunsaturated fatty acids correlated negatively, reflecting cell membrane fluidity regulation, which is necessary for coral to tolerate changing temperatures. Spawning and maternal provisioning also proved to be a major driver of change in the coral lipid profile. The mass spawning events in spring for both 2009 and 2010 caused reductions in the important coral egg constituents: wax ester, triacylglycerol, phosphatidylcholine and fatty acid 10:0. Interestingly, lipid accumulation was significantly lower in the 2010 spawn compared to 2009, possibly due to lower PAR and chlorophyll levels, reflecting reduced photosynthetic activity and phytoplankton availability. Regardless, in 2010, resource provisioning to egg production was greater than in 2009, suggesting increased reproductive effort in the face of environmental stress. This study demonstrates the strong influence of opportunistic heterotrophy and autotrophy and maternal provisioning on the coral lipid profile. Such information is fundamental to understanding the environmental and biochemical processes underlying coral health and predicting how anomalous events and climate-driven changes will affect coral reef assemblages. [ABSTRACT FROM AUTHOR]

Introduction: Postprandial hyperglycemia (PPH) impairs vascular endothelial function (VEF). A single bout of aerobic exercise (AE) attenuates PPH-induced decreases in brachial artery flow-mediated dilation (FMD), a non-invasive measure of VEF, in healthy adults for up to 17 h post-exercise. Studies examining the effects of resistance exercise (RE) on postprandial FMD responses are lacking.Purpose: We hypothesized that a single bout of exercise performed the prior evening would attenuate PPH-induced decreases in FMD, independent of exercise modality.Methods: In a randomized, cross-over design, overweight/obese adults [n = 11 (8 women); 22 ± 4 years; 32.3 ± 5.8 kg m-2] completed 3 separate trials: control (seated rest), AE (30 min at ~ 60% VO2max), or whole-body RE (30 min, 6 exercises, 3 × 10-repetition maximum). Each trial occurred 14-17 h prior to an oral glucose tolerance test (OGTT). Brachial artery FMD and plasma glucose and insulin were measured prior to and at 30-min intervals for 2 h following the OGTT. Repeated-measures ANOVA and Bonferroni post hoc tests were used to evaluate differences within and between trials.Results: Trials occurred 15.3 ± 1.0 h prior to the OGTT. Relative to baseline, FMD transiently decreased (P < 0.05) at 30-60 min post-ingestion, plasma glucose increased (P < 0.01) at 30-90 min post-ingestion, and plasma insulin increased (P < 0.01) at 30-120 min post-ingestion. No between trial differences were observed for FMD, glucose, or insulin.Conclusions: Aerobic or resistance exercise performed the evening prior to an OGTT does not attenuate postprandial decreases in brachial artery FMD in overweight/obese adults. [ABSTRACT FROM AUTHOR]

Background: Francisella tularensis subspecies tularensis is the causative agent of a spectrum of diseases collectively known as tularemia. An attenuated live vaccine strain (LVS) has been shown to be efficacious in humans, but safety concerns have prevented its licensure by the FDA. Recently, F. tularensis LVS has been produced under Current Good Manufacturing Practice (CGMP guidelines). Little is known about the immunogenicity of this new vaccine preparation in comparison with extensive studies conducted with laboratory passaged strains of LVS. Thus, the aim of the current work was to evaluate the repertoire of antibodies produced in mouse strains vaccinated with the new LVS vaccine preparation. Methodology/Principal Findings: In the current study, we used an immunoproteomics approach to examine the repertoire of antibodies induced following successful immunization of BALB/c versus unsuccessful vaccination of C57BL/6 mice with the new preparation of F. tularensis LVS. Successful vaccination of BALB/c mice elicited antibodies to nine identified proteins that were not recognized by antisera from vaccinated but unprotected C57BL/6 mice. In addition, the CGMP formulation of LVS stimulated a greater repertoire of antibodies following vaccination compared to vaccination with laboratory passaged ATCC LVS strain. A total of 15 immunoreactive proteins were identified in both studies, however, 16 immunoreactive proteins were uniquely reactive with sera from the new formulation of LVS. Conclusions/Significance: This is the first report characterising the antibody based immune response of the new formulation of LVS in the widely used murine model of tularemia. Using two mouse strains, we show that successfully vaccinated mice can be distinguished from unsuccessfully vaccinated mice based upon the repertoire of antibodies generated. This opens the door towards downselection of antigens for incorporation into tularemia subunit vaccines. In addition, this work also highlights differences in the humoral immune response to vaccination with the commonly used laboratory LVS strain and the new vaccine formulation of LVS. [ABSTRACT FROM AUTHOR]

This study examined the role of lymphotoxin (LT)-α in host defense against airborne infection with Francisella tularensis, a gram-negative facultative intracellular bacterium and the causative agent of tularemia. Following a low-dose aerosol infection with the highly virulent type A strain of F. tularensis, mice deficient in LTα (LTα-/-) consistently harbored approximately 10-fold fewer bacteria in their spleens at day 2 and 10-fold more bacteria in their lungs at day 4 than LTα+/+ mice. However, the mortality and median time to death were indistinguishable between the two mouse strains. In addition, the inflammatory responses to the infection, as reflected by the cytokine levels and leukocyte influx in the bronchoalveolar lavage fluid and histopathological analysis, were generally similar between LTα-/- and LTα+/+ mice. These data suggest that although LTα does not contribute significantly to the resistance and host responses of mice to airborne type A F. tularensis infection, it does play a subtle role in the multiplication/dissemination of F. tularensis. [ABSTRACT FROM AUTHOR]

This study examined the role of lymphotoxin (LT)-α in host defense against airborne infection with Francisella tularensis, a gramnegative facultative intracellular bacterium and the causative agent of tularemia. Following a low-dose aerosol infection with the highly virulent type A strain of F. tularensis, mice deficient in LTα (LTα-/-) consistently harbored approximately 10-fold fewer bacteria in their spleens at day 2 and 10-fold more bacteria in their lungs at day 4 than LTα+/+ mice. However, the mortality and median time to death were indistinguishable between the two mouse strains. In addition, the inflammatory responses to the infection, as reflected by the cytokine levels and leukocyte influx in the bronchoalveolar lavage fluid and histopathological analysis, were generally similar between LTα-/- and LTα+/+ mice. These data suggest that although LTα does not contribute significantly to the resistance and host responses of mice to airborne type A F. tularensis infection, it does play a subtle role in the multiplication/dissemination of F. tularensi. [ABSTRACT FROM AUTHOR]

Francisella tularensis is one of the most pathogenic pathogens known, especially when disseminated as a small particle aerosol. Because of this, it was developed into a biological warfare agent by several states during the 20th century. Nowadays, concerns remain about the potential of this pathogen to cause widespread disease, tularemia, in the hands of terrorists. This has resurrected interest in methods to combat it. This article reviews the current status of vaccine development efforts against tularemia. To date most of our understanding of tularemia vaccine efficacy has been derived from the clinical and experimental use of a pragmatically attenuated live vaccine strain of F. tularensis subspecies holarctica. However, this vaccine which has been in existence for more than 50 years is still beset by regulatory issues that continue to hamper its licensure. These issues and possible solutions are highlighted, along with more modern molecular approaches to vaccine development against this highly virulent pathogen. [ABSTRACT FROM AUTHOR]

The structure of the lipid A and core region of the lipopolysaccharide (LPS) from Francisella tularensis (ATCC 29684) was analysed using NMR, mass spectrometry and chemical methods. The LPS contains a β-GlcN-(1–6)-GlcN lipid A backbone, but has a number of unusual structural features; it apparently has no substituent at O-1 of the reducing end GlcN residue in the lipid part in the major part of the population, no substituents at O-3 and O-4 of β-GlcN, and no substituent at O-4 of the Kdo residue. The largest oligosaccharide, isolated after strong alkaline deacylation of NaBH4 reduced LPS had the following structure: &figfu1; where Δ-GalNA-(1–3)-β-QuiNAc represents a modified fragment of the O-chain repeating unit. Two shorter oligosaccharides lacking the O-chain fragment were also identified. A minor amount of the disaccharide β-GlcN-(1–6)-α-GlcN-1-P was isolated from the same reaction mixture, indicating the presence of free lipid A, unsubstituted by Kdo and with phosphate at the reducing end. The lipid A, isolated from the products of mild acid hydrolysis, had the structure 2-N -(3-O-acyl4 -acyl2 )-β-GlcN-(1–6)-2-N -acyl1 -3-O-acyl3 -GlcN where acyl1 , acyl2 and acyl3 are 3-hydroxyhexadecanoic or 3-hydroxyoctadecanoic acids, acyl4 is tetradecanoic or (minor) hexadecanoic acids. No phosphate substituents were found in this compound. OH-1 of the reducing end glucosamine, and OH-3 and OH-4 of the nonreducing end glucosamine residues were not substituted. LPS of F. tularensis exhibits unusual biological properties, including low endoxicity, which may be related to its unusual lipid A structure. [ABSTRACT FROM AUTHOR]

Helicobacter pylori is a widespread Gram-negative bacterium responsible for the onset of various gastric pathologies and cancers in humans. A familiar trait of H. pylori is the production of cell-surface lipopolysaccharides (LPSs; O-chain core lipid A) with O-chain structures analogous to some mammalian histo-blood-group antigens, those being the Lewis determinants (Le[sup a] , Le[sup b] , Le[sup x] , sialyl Le[sup x] , Le[sup y] ) and blood groups A and linear B. Some of these LPS antigens have been implicated as autoimmune, adhesion, and colonization components of H. pylori pathogenic mechanisms. This article describes the chemical structures of LPSs from H. pylori isolated from subjects with no overt signs of disease. Experimental data from chemical- and spectroscopic-based studies unanimously showed that these H. pylori manufactured extended heptoglycans composed of 2- and 3-linked D-glycero-α-D-manno-heptopyranose units and did not express any blood-group O-antigen chains. The fact that another H. pylori isolate with a similar LPS structure was shown to be capable of colonizing mice indicates that H. pylori histo-blood-group structures are not an absolute prerequisite for colonization in the murine model also. The absence of O-chains with histo-blood groups may cause H. pylori to become inept in exciting an immune response. Additionally, the presence of elongated heptoglycans may impede exposure of disease-causing outer-membrane antigens. These factors may render such H. pylori incapable of creating exogenous contacts essential for pathogenesis of severe gastroduodenal diseases and suggest that histo-blood groups in the LPS may indeed play a role in inducing a more severe H. pylori pathology.Key words: lipopolysaccharide, carbohydrates, glycobiology, Helicobacter pylori, histo-blood groups.Helicobacter pylori est une bactérie à Gram négatif très répandue qui est à l'origine de divers cancers et pathologies gastriques chez les humains. Une des caractéristiques de H. pylori est de synthétiser des lipopolysaccharides (LPS) de surface ayant une structure de chaîne O (chaîne O coeur lipide A) analogue à des antigènes de groupes histo-sanguins de mammifères : les déterminants de Lewis (Le[sup a] , Le[sup b] , Le[sup x] , Le[sup x] sialylé, Le[sup y] ) et les groupes sanguins A et B linéaire. Certains de ces antigènes LPS interviennent dans les mécanismes pathogènes de H. pylori, entre autres dans l'auto-immunité, l'adhésion et la colonisation. Cet article décrit les structures chimiques des LPS de H. pylori isolé de personnes n'ayant aucun signe apparent de maladie. Les résultats d'études chimiques et spectroscopiques montrent tous que H. pylori synthétise de longs heptoglycanes constitués d'unités de D-glycéro-α-D-manno-heptopyranose liées en 2 ou 3 et qu'il n'exprime aucune des chaînes de l'antigène du groupe sanguin O. Un autre isolat de H. pylori ayant une structure LPS similaire peut coloniser des souris, ce qui indique que les structures des groupes histo-sanguins de H. pylori ne sont également pas un prérequis absolu pour la colonisation des souris. L'absence de chaînes O dans les groupes histo-sanguins peut faire en sorte que H. pylori est incapable d'induire une réponse immune. De plus, la présence de longs heptoglycanes pourrait cacher des antigènes de la membrane externe qui entraînent une maladie, ce qui rendrait H. pylori incapable d'établir les contacts exogènes essentiels pour la pathogenèse de maladies gastro-duodénales graves. Cela suggère que les LPS des groupes histo-sanguins peuvent effectivement jouer un rôle dans l'induction d'une pathologie plus grave par H. pylori.Mots clés : lipopolysaccharides, glucides, glycobiologie, Helicobacter pylori, groupes histo-sanguins.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

In an attempt to improve upon a current mouse model of intestinal colonization by Escherichia coli O157:H7 used in this laboratory for vaccine development, nine clinical isolates of the pathogen were screened for their ability to persist in the intestinal tract of conventional adult CD-1 mice. None of the test isolates of E. coli O157:H7 were capable of colonizing these mice for a period of more than two weeks. Most of the isolates appeared to be benign for the experimental host, but one isolate was lethal. This virulence correlated with the ability of the latter isolate to produce large quantities of Shiga-like toxin 2 in vitro.Dans une tentative d'améliorer un modèle murin actuel de colonisation intestinale par Escherichia coli O157:H7 utilisé dans ce laboratoire pour le développement de vaccins, neufs isolats cliniques du pathogène furent criblés selon leur capacité à persister dans le tractus intestinal de souris CD1 adultes conventionnelles. Aucun des isolats de E. coli O157:H7 testés ne furent capables de coloniser ces souris sur une période de plus de deux semaines. La plupart des isolats semblèrent être bénins pour l'hôte expérimental, mais un isolat fut létal. Cette virulence montra une corrélation avec la capacité du dernier isolat à produire d'importantes quantités de toxine simili-Shiga 2 in vitro.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

A previously annotated open reading frame (ORF) (HP0826) from Helicobacter pylori was cloned and expressed in Escherichia coli cells and determined to be a β-1,4-galactosyltransferase that used GlcNAc as an acceptor. Mutational analysis in H. pylori strains demonstrated that this enzyme plays a key role in the biosynthesis of the type 2 N-acetyl-lactosamine (LacNAc) polysaccharide O-chain backbone, by catalysing the addition of Gal to GlcNAc. To examine the potential role of this O-chain structure in bacterial colonization of the host stomach, the mutation was introduced into H. pylori strain SS1 which is known to be capable of colonizing the gastric mucosa of mice. Compared with the parental strain, mutated SS1 was less efficient at colonizing the murine stomach. [ABSTRACT FROM AUTHOR]

Inhalation of small numbers of Francisella tularensis subspecies tularensis (Ftt) in the form of small particle aerosols causes severe morbidity and mortality in people and many animal species. For this reason, Ftt was developed into a bona fide biological weapon by the USA, by the former USSR, and their respective allies during the previous century. Although such weapons were never deployed, the 9/11 attack quickly followed by the Amerithrax attack led the U.S. government to seek novel countermeasures against a select group of pathogens, including Ftt. Between 2005–2009, we pursued a novel live vaccine against Ftt by deleting putative virulence genes from a fully virulent strain of the pathogen, SCHU S4. These mutants were screened in a mouse model, in which the vaccine candidates were first administered intradermally (ID) to determine their degree of attenuation. Subsequently, mice that survived a high dose ID inoculation were challenged by aerosol or intranasally (IN) with virulent strains of Ftt. We used the current unlicensed live vaccine strain (LVS), first discovered over 70 years ago, as a comparator in the same model. After screening 60 mutants, we found only one, SCHU S4 ΔclpB, that outperformed LVS in the mouse ID vaccination-respiratory-challenge model. Currently, SCHU S4 ΔclpB has been manufactured under current good manufacturing practice conditions, and tested for safety and efficacy in mice, rats, and macaques. The steps necessary for advancing SCHU S4 ΔclpB to this late stage of development are detailed herein. These include developing a body of data supporting the attenuation of SCHU S4 ΔclpB to a degree sufficient for removal from the U.S. Select Agent list and for human use; optimizing SCHU S4 ΔclpB vaccine production, scale up, and long-term storage; and developing appropriate quality control testing approaches. [ABSTRACT FROM AUTHOR]

The article focuses on the impact of the plays created by William Shakespeare to the literature of the Virginia propagandists. It highlights the play "The Tempest" which was cited as the most dependent on the literature of the sector. It has provoked a controversial debate on its ontology as a political statement. It further reveals that the realism of the play rested on a footing comparable to other truth-bearing discourses.

The major outer membrane protein (MOMP) is the prime candidate for the development of a chlamydial vaccine. Antibodies to the subspecies-specific epitope neutralize chlamydial infection. Monoclonal antibodies (MAbs) to this epitope were prepared either by immunization with whole chlamydiae or with a 16 amino acid synthetic peptide. The critical binding site on the subspecies epitope for these MAbs was determined to single amino acid resolution using several hundred solid-phase peptides. A frame shift of just one amino acid in critical binding site completely prevented antibody binding to viable chlamydiae. A single MAb to whole organisms was capable of spanning both the surface-exposed, conformation-dependent, subspecies epitope and a buried, conformation-independent species epitope some 10 Å distant. Immunization with peptide generated an MAb with reduced binding constraints which permitted the antibody to bind with broadened species-specificity at the subspecies binding site. The results show for the first time the importance of both critical binding site and conformation at the subspecies epitope. We suggest that the conformational flexibility of short, epitopic peptide vaccines may in some cases be advantageous, giving rise to extended specificity not attained with the natural protein. [ABSTRACT FROM AUTHOR]

The major outer membrane protein (MOMP) of Chlamydia trachomatis carries serovar-, subspecies-, species- and genus immunodomains, antibodies to which may be protective. We have compared the inferred amino acid sequences for MOMP from different serovars of C. trachomatis and from Chlamydia psittaci to identify the likely locations of these sero-taxonomic epitopes. Overlapping peptides corresponding to each of these regions were synthesized on a solid phase and probed with monoclonal antibodies (MAbs) of appropriate specificities. We describe the primary structures of the binding sites of MAb to each of these four epitopes on C. trachomatis serovar L1 MOMP. [ABSTRACT FROM AUTHOR]

Serogroup-specific antigen was extracted from a number of Legionella pneumophila strains and compared with phenol-water extracted lipopolysaccharide on the basis of gel filtration, chemical analysis, SDS-PAGE and reaction with serogroup-specific antibody in immunoblots. Serogroup specificity is apparently borne by the O side-chains of the lipopolysaccharide, which, although smooth in type, partitions in the phenol phase. For four serogroup 1 strains tested, there was no qualitative correlation between O side-chain length and pulmonary virulence for guinea-pigs. [ABSTRACT FROM PUBLISHER]

Aqueous suspensions of virulent Legionellapneumophila grown on solid medium retained virulence and aerosol survival characteristics for several months. Significant numbers of viable organisms were recovered from aerosols held at various relative humidities (r.h.) for up to 2 h. The organisms survived best at 65% r.h. and were least stable at 55% r.h.Exponential phase broth-grown organisms survived poorly in aerosols in comparison with stationary phase broth cultures or organisms grown on solid medium, suggesting that the metabolic status of Legionella pneumophila organisms may be an important factor affecting their ability to survive in aerosols and cause respiratory disease. [ABSTRACT FROM PUBLISHER]