Identification of a novel transport system in Borrelia burgdorferi that links the inner and outer membranes

Borrelia burgdorferi, the spirochete that causes Lyme disease, is a diderm organism that is similar to Gram-negative organisms in that it contains both an inner and outer membrane. Unlike typical Gram-negative organisms, however, B. burgdorferi lacks lipopolysaccharide (LPS). Using computational genome analyses and structural modeling, we identified a transport system containing six proteins in B. burgdorferi that are all orthologs to proteins found in the lipopolysaccharide transport (LPT) system that links the inner and outer membranes of Gram-negative organisms and is responsible for placing LPS on the surface of these organisms. While B. burgdorferi does not contain LPS, it does encode over 100 different surface-exposed lipoproteins and several major glycolipids, which like LPS are also highly amphiphilic molecules, though no system to transport these molecules to the borrelial surface is known. Accordingly, experiments supplemented by molecular modeling were undertaken to determine whether the orthologous LPT system identified in B. burgdorferi could transport lipoproteins and/or glycolipids to the borrelial outer membrane. Our combined observations strongly suggest that the LPT transport system does not transport lipoproteins to the surface. Molecular dynamic modeling, however, suggests that the borrelial LPT system could transport borrelial glycolipids to the outer membrane

Dise?o, construcci?n y equipamiento de un centro de informaci?n para la investigaci?n en la Facultad de Ingenier?a Civil de la Universidad Nacional de Ingenier?a

La facultad de ingenier?a civil de la universidad nacional de ingenier?a, busca promover la investigaci?n en sus alumnos tanto de pregrado como de postgrado, motivo por el que se tuvo la iniciativa de contar con una infraestructura adicional cuya funci?n ser? de un centro de informaci?n e investigaci?n. El presente estudio tiene como objetivo desarrollar los planes de gesti?n de una infraestructura que se integre a la infraestructura existente, que sea duradero y que permita el desarrollo de la investigaci?n de los estudiantes, que cumpla con los requisitos del proyecto y satisfaga las expectativas del cliente. Esta construcci?n tendr? la particularidad que en sus bases se coloquen aisladores s?smicos, es preciso resaltar que este edificio es el primero en una universidad p?blica en el Per? al que se le va a instalar aisladores s?smicos; adem?s, ser? sostenible con la implementaci?n de un techo verde en su ?ltimo nivel Este edificio tendr? los servicios necesarios de acuerdo a lo solicitado por el cliente (UNI) sin que la realizaci?n del proyecto pueda afectar las actividades acad?micas que desarrolla. Por ende, en el presente trabajo ha sido importante identificar, evaluar y aplicar los planes de acciones respectivos a los ?stakeholders? del proyecto

Two New Loci for Body-Weight Regulation Identified in a Joint Analysis of Genome-Wide Association Studies for Early-Onset Extreme Obesity in French and German Study Groups

Meta-analyses of population-based genome-wide association studies (GWAS) in adults have recently led to the detection of new genetic loci for obesity. Here we aimed to discover additional obesity loci in extremely obese children and adolescents. We also investigated if these results generalize by estimating the effects of these obesity loci in adults and in population-based samples including both children and adults. We jointly analysed two GWAS of 2,258 individuals and followed-up the best, according to lowest p-values, 44 single nucleotide polymorphisms (SNP) from 21 genomic regions in 3,141 individuals. After this DISCOVERY step, we explored if the findings derived from the extremely obese children and adolescents (10 SNPs from 5 genomic regions) generalized to (i) the population level and (ii) to adults by genotyping another 31,182 individuals (GENERALIZATION step). Apart from previously identified FTO, MC4R, and TMEM18, we detected two new loci for obesity: one in SDCCAG8 (serologically defined colon cancer antigen 8 gene; p = 1.85610 x 10(-8) in the DISCOVERY step) and one between TNKS (tankyrase, TRF1-interacting ankyrin-related ADP-ribose polymerase gene) and MSRA (methionine sulfoxide reductase A gene; p = 4.84 x 10(-7)), the latter finding being limited to children and adolescents as demonstrated in the GENERALIZATION step. The odds ratios for early-onset obesity were estimated at similar to 1.10 per risk allele for both loci. Interestingly, the TNKS/MSRA locus has recently been found to be associated with adult waist circumference. In summary, we have completed a meta-analysis of two GWAS which both focus on extremely obese children and adolescents and replicated our findings in a large followed-up data set. We observed that genetic variants in or near FTO, MC4R, TMEM18, SDCCAG8, and TNKS/MSRA were robustly associated with early-onset obesity. We conclude that the currently known major common variants related to obesity overlap to a substantial degree between children and adults

Borrelia burgdorferi BBK32 Inhibits the Classical Pathway by Blocking Activation of the C1 Complement Complex

Citation: Garcia, B. L., Zhi, H., Wager, B., Hook, M., & Skare, J. T. (2016). Borrelia burgdorferi BBK32 Inhibits the Classical Pathway by Blocking Activation of the C1 Complement Complex. Plos Pathogens, 12(1), 28. doi:10.1371/journal.ppat.1005404Pathogens that traffic in blood, lymphatics, or interstitial fluids must adopt strategies to evade innate immune defenses, notably the complement system. Through recruitment of host regulators of complement to their surface, many pathogens are able to escape complement-mediated attack. The Lyme disease spirochete, Borrelia burgdorferi, produces a number of surface proteins that bind to factor H related molecules, which function as the dominant negative regulator of the alternative pathway of complement. Relatively less is known about how B. burgdorferi evades the classical pathway of complement despite the observation that some sensu lato strains are sensitive to classical pathway activation. Here we report that the borrelial lipoprotein BBK32 potently and specifically inhibits the classical pathway by binding with high affinity to the initiating C1 complex of complement. In addition, B. burgdorferi cells that produce BBK32 on their surface bind to both C1 and C1r and a serum sensitive derivative of B. burgdorferi is protected from killing via the classical pathway in a BBK32-dependent manner. Subsequent biochemical and biophysical approaches localized the anti-complement activity of BBK32 to its globular C-terminal domain. Mechanistic studies reveal that BBK32 acts by entrapping C1 in its zymogen form by binding and inhibiting the C1 subcomponent, C1r, which serves as the initiating serine protease of the classical pathway. To our knowledge this is the first report of a spirochetal protein acting as a direct inhibitor of the classical pathway and is the only example of a biomolecule capable of specifically and noncovalently inhibiting C1/C1r. By identifying a unique mode of complement evasion this study greatly enhances our understanding of how pathogens subvert and potentially manipulate host innate immune systems

Immunization with a Borrelia burgdorferi BB0172-Derived Peptide Protects Mice against Lyme Disease

Lyme disease is the most prevalent arthropod borne disease in the US and it is caused by the bacterial spirochete Borrelia burgdorferi (Bb), which is acquired through the bite of an infected Ixodes tick. Vaccine development efforts focused on the von Willebrand factor A domain of the borrelial protein BB0172 from which four peptides (A, B, C and D) were synthesized and conjugated to Keyhole Limpet Hemocyanin, formulated in Titer Max® adjuvant and used to immunize C3H/HeN mice subcutaneously at days 0, 14 and 21. Sera were collected to evaluate antibody responses and some mice were sacrificed for histopathology to evaluate vaccine safety. Twenty-eight days post-priming, protection was evaluated by needle inoculation of half the mice in each group with 103 Bb/mouse, whereas the rest were challenged with 105Bb/mouse. Eight weeks post-priming, another four groups of similarly immunized mice were challenged using infected ticks. In both experiments, twenty-one days post-challenge, the mice were sacrificed to determine antibody responses, bacterial burdens and conduct histopathology. Results showed that only mice immunized with peptide B were protected against challenge with Bb. In addition, compared to the other the treatment groups, peptide B-immunized mice showed very limited inflammation in the heart and joint tissues. Peptide B-specific antibody titers peaked at 8 weeks post-priming and surprisingly, the anti-peptide B antibodies did not cross-react with Bb lysates. These findings strongly suggest that peptide B is a promising candidate for the development of a new DIVA vaccine (Differentiate between Infected and Vaccinated Animals) for protection against Lyme disease.The open access fee for this work was funded through the Texas A&M University Open Access to Knowledge (OAK) Fund

A unified model for BAM function that takes into account type Vc secretion and species differences in BAM composition

Transmembrane proteins in the outer membrane of Gram-negative bacteria are almost exclusively β-barrels. They are inserted into the outer membrane by a conserved and essential protein complex called the BAM (for β-barrel assembly machinery). In this commentary, we summarize current research into the mechanism of this protein complex and how it relates to type V secretion. Type V secretion systems are autotransporters that all contain a β-barrel transmembrane domain inserted by BAM. In type Vc systems, this domain is a homotrimer. We argue that none of the current models are sufficient to explain BAM function particularly regarding type Vc secretion. We also find that current models based on the well-studied model system Escherichia coli mostly ignore the pronounced differences in BAM composition between different bacterial species. We propose a more holistic view on how all OMPs, including autotransporters, are incorporated into the lipid bilayer

The facts and the lessons of Listowel : a study of the factors relating to the collapse of Listowel arena and the lessons to be drawn from the tragedy in the interests of public safety

The paper presents a study of the factors relating to the collapse of the Listowel hockey arena of 28 February 1959, in which nearly the entire roof of the 110 by 240 ft building fell in, resulting in eight deaths. The snow on the barrel-shaped roof was heavy along one side only. The main roof members were glued-laminated bow-string trusses of 110 ft span supported by rather high and slender masonry walls. An inquest revealed, as the main factors in the failure, the absence of engineering or architectural supervision during construction and poor workmanship in the glued-laminated truss chords. A number of lessons can be drawn from the tragedy relating to the preparation of plans for public assembly buildings by a registered professional architect or engineer, the approval of plans by a municipal or perhaps a higher authority, the use of building codes, and the examination of existing buildings.On \ue9tudie dans cet article les facteurs li\ue9s \ue0 l' effondrement de l'ar\ue8ne de hockey de Listowel le 28 f\ue9vrier 1959. Lors de cet accident la presque totalit\ue9 de la toiture de l'ar\ue8ne mesurant 110 pieds par 240 pieds s'est effondr\ue9e et a tu\ue9 huit personnes. La neige qui se trouvait sur le toit bomb\ue9 n'\ue9tait \ue9paisse que d'un c\uf4t\ue9. Les principales poutres du toit \ue9taient compos\ue9es d'\ue9l\ue9ments lamin\ue9s en forme d'arc et coll\ue9s et elles avaient une envergure de 110 pieds soutenue par des murs de maconnerie \ue9 lev\ue9s et peu \ue9pais. L'enqu\ueate a r\ue9v\ue9l\ue9 comme principaux facteurs de l'accident l'absence d'un contr\uf4le technique ou architectural durant la construction et un mauvais travail dans l'assemblage des \ue9l\ue9ments lamin\ue9s. On peut tirer un certain nombre de lecons de cette trag\ue9die. On peut par exemple dire que la pr\ue9paration des plans des b\ue2timents devant servir \ue0 des r\ue9unions publiques doit \ueatre effectu\ue9e par des architectes ou des ing\ue9nieurs qualifi\ue9s; les plans doivent \ueatre approuv\ue9s par une autorit\ue9 municipale ou peut-\uea tre une autorit\ue9 \ue0 un \ue9chelon plus \ue9lev\ue9; des codes du b\ue2timent doivent \ueatre utilis\ue9s; on doit se renseigner sur les b\ue2timents qui existent d\ue9j\ue0.Peer reviewed: NoNRC publication: Ye