Identification and characterization of novel recombinant vaccine antigens for immunization against genital Chlamydia trachomatis

Chlamydia trachomatis infection is the most common sexually transmitted bacterial infection worldwide, with over 91 million cases estimated annually. An effective subunit vaccine against Chlamydia may require a multivalent subunit cocktail of antigens in a single formulation for broad coverage of a heterogeneous major histocompatibility complex population. Herein, we describe the identification of novel C. trachomatis antigens by CD4+ and CD8+ T-cell expression cloning, serological expression cloning, and an in silico analysis of the C. trachomatis genome. These antigens elicited human CD4+ T-cell responses, and a subset proved to be immunogenic and protective when administered as immunoprophylactic vaccines against C. trachomatis challenge. Candidate vaccines consisting of the prioritized C. trachomatis antigens adjuvanted in a GlaxoSmithKline proprietary AS01B adjuvant were prioritized based on induction of solid protection against challenge in C57BL/6 and BALB/c mice with C. trachomatis . Some of the vaccines prevented bacterial shedding and colonization of the upper genital tract to varying degrees by mechanisms that may include CD4+ T cells.     

Validation of a Nylon-Flocked-Swab Protocol for Efficient Recovery of Bacterial Spores from Smooth and Rough Surfaces

In order to meet planetary-protection requirements, culturable bacterial spore loads are measured representatively for the total microbial contamination of spacecraft. However, the National Aeronautics and Space Administration''s (NASA''s) cotton swab protocols for spore load determination have not changed for decades. To determine whether a more efficient alternative was available, a novel swab was evaluated for recovery of different Bacillus atrophaeus spore concentrations on stainless steel and other surfaces. Two protocols for the nylon-flocked swab (NFS) were validated and compared to the present NASA standard protocol. The results indicate that the novel swab protocols recover 3- to 4-fold more (45.4% and 49.0% recovery efficiency) B. atrophaeus spores than the NASA standard method (13.2%). Moreover, the nylon-flocked-swab protocols were superior in recovery efficiency for spores of seven different Bacillus species, including Bacillus anthracis Sterne (recovery efficiency, 20%). The recovery efficiencies for B. atrophaeus spores from different surfaces showed a variation from 5.9 to 62.0%, depending on the roughness of the surface analyzed. Direct inoculation of the swab resulted in a recovery rate of about 80%, consistent with the results of scanning electron micrographs that allowed detailed comparisons of the two swab types. The results of this investigation will significantly contribute to the cleanliness control of future life detection missions and will provide significant improvement in detection of B. anthracis contamination for law enforcement and security efforts.The recent discovery of liquid water on Mars has sparked debate about the possibility of extraterrestrial life (37). Consequently, highly sensitive biosensors will be deployed onboard spacecraft like the Mars Science Laboratory (MSL), using technologies such as gas chromatographical analysis to search for the smallest traces of life (http://mars.jpl.nasa.gov/msl/mission/). Contamination of equipment by terrestrial microorganisms resulting from a lack of spacecraft cleanliness could significantly compromise the integrity of life detection missions and result in falsely positive extraterrestrial life signals. The prevention of this so-called “forward contamination” is one major goal of American and European space agencies'' planetary-protection efforts. Regular determination of a spacecraft''s bioload and the mission components throughout assembly are mandatory for detecting unacceptably high contamination that exceeds levels set by the United Nations treaty (Outer Space Treaty [11]).Modern spacecraft hardware is very susceptible to standard heat sterilization protocols, so baking the entire spacecraft, such as the Viking Lander Capsule at 111.7°C ± 1.7°C for 23 to 30 h is no longer feasible (30). Alternative cleaning and sterilization methodologies for spacecraft components prior to assembly (i.e., nonthermal plasma technologies) have been discussed (36). However, after integration, sterile hardware is exposed to a significant risk of contamination during assembly, testing, and launching operations. Because of limited access to integrated spacecraft components, the microbial cleanliness of a spacecraft and its surroundings is meticulously maintained through frequent cleaning and sterilization routines. Therefore, the regular and frequent detection of possible contaminants in the assembly environment is more important than ever.To estimate the severity of microbial contamination, the National Aeronautics and Space Administration''s (NASA''s) standard procedure focuses on aerobic, mesophilic spores (26). Briefly, surface samples are taken from spacecraft using moist cotton swabs or wipes. After an extraction procedure, the samples are subjected to a short heat shock (15 min; 80°C) to kill vegetative cells and then pour plated in Trypticase soy agar (TSA) for the enumeration of CFU. This protocol was originally developed for the Viking mission more than 3 decades ago (30) and has remained, for the most part, unchanged.Recent studies have shown that cotton swabs have acceptable recovery efficiencies for Bacillus spores (41.7%) (32) but, due to their organic nature, may raise residue problems on surfaces. Furthermore, their comparatively high DNA content could lead to false positives or inhibition should NASA one day incorporate molecular technologies into their microbial-detection protocols (7).Based on these observations, researchers are beginning to move away from cotton in favor of alternative swabs made from rayon or macrofoam (6, 18). A recent study reported high recovery efficiencies for various vegetative cells from stainless steel surfaces by applying a novel swab with a bulb-shaped head flocked with nylon fibers (12). Patented in 2004, this design facilitates the release of particulates and microbes, resulting in a significantly higher detection rate. The broad applicability of these nylon-flocked swabs (NFS) has been demonstrated by their use in various clinical studies isolating pathogens from medical environments (1, 10, 20).General studies on surface-sampling tools have clearly shown that the swab material and the extraction method are the dominant factors in spore recovery efficiencies (32). Additionally, the properties of the surface to be sampled affect sample recovery (8). For planetary-protection applications, the broad variety of novel materials used in spacecraft construction must be considered. The Mars Exploration Rover mission craft, for example, was composed of at least five kinds of surface materials (http://marsrovers.jpl.nasa.gov/overview). While the cruise stage was constructed primarily of aluminum and the aeroshell consisted of aluminum honeycomb structures, the lander itself was made of titanium and graphite composite (carbon fiber-reinforced plastic [CFRP]). The airbag and the parachutes were made of Vectran and polyester/nylon fabrics. These different materials are quite challenging for sampling tools. Accurate sampling of materials with various surface textures will require planetary-protection programs to introduce novel swab materials.To our knowledge, no investigations have been performed to compare the recovery of spores from different spacecraft surfaces. Previous studies have compared cotton and synthetic sampling materials, but only on stainless steel surfaces (19), and no studies have compared sampling methods on actual spacecraft materials (7).Recently published protocols for spore detection have been based on one specific Bacillus species and/or on one type of surface. Unfortunately, these protocols provide no insight into the effects of varying these factors (4-6, 8, 9, 14, 18), as requested by USP (United States Pharmacopeia) 1223 for validation of alternative microbial methods (3). Some of the aforementioned studies were conducted in response to B. anthracis terrorism incidents in 2001 and used B. atrophaeus as a surrogate. Consequently, information about the actual sampling efficiency of B. anthracis spores is quite limited and may vary significantly from the B. atrophaeus data.In this comprehensive study, we evaluated the novel nylon-flocked swab and a corresponding protocol to recover Bacillus spores from five different spacecraft-related surfaces. It should be noted that although stainless steel served as the standard test surface, it is not a predominant material in spacecraft; however, since the majority of previous (sampling) studies were performed on stainless steel, it represents a universally recognized carrier and also serves as a conservative proxy for the average roughness of the materials used in space science.Our nylon-flocked-swab protocol was validated with respect to accuracy, precision, limit of detection, linearity, and robustness (3). Moreover, its specificity was determined by applying spores of seven different Bacillus species, including the avirulent, attenuated strain Bacillus anthracis Sterne, and by comparing the resulting recovery efficiencies. The results in this communication will significantly contribute to planetary-protection protocols and could also be of high interest for public health issues.     

Design of an orally efficacious hydroxyethylamine (HEA) BACE-1 inhibitor in a preclinical animal model

In this Letter, we describe our efforts to design HEA BACE-1 inhibitors that are highly permeable coupled with negligible levels of permeability-glycoprotein activity. These efforts culminate in producing 16 which lowers Αβ by 28% and 32% in the cortex and CSF, respectively, in the preclinical wild type Hartley guinea pig animal model when dosed orally at 30 mpk BID for 2.5 days.     

Improving the permeability of the hydroxyethylamine BACE-1 inhibitors: Structure–activity relationship of P2′ substituents

Herein we describe further evolution of hydroxyethylamine inhibitors of BACE-1 with enhanced permeability characteristics necessary for CNS penetration. Variation at the P2′ position of the inhibitor with more polar substituents led to compounds 19 and 32, which retained the potency of more lipophilic analog 1 but with much higher observed passive permeability in MDCK cellular assay.     

CAF-1 is essential for heterochromatin organization in pluripotent embryonic cells

During mammalian development, chromatin dynamics and epigenetic marking are important for genome reprogramming. Recent data suggest an important role for the chromatin assembly machinery in this process. To analyze the role of chromatin assembly factor 1 (CAF-1) during pre-implantation development, we generated a mouse line carrying a targeted mutation in the gene encoding its large subunit, p150CAF-1. Loss of p150CAF-1 in homozygous mutants leads to developmental arrest at the 16-cell stage. Absence of p150CAF-1 in these embryos results in severe alterations in the nuclear organization of constitutive heterochromatin. We provide evidence that in wild-type embryos, heterochromatin domains are extensively reorganized between the two-cell and blastocyst stages. In p150CAF-1 mutant 16-cell stage embryos, the altered organization of heterochromatin displays similarities to the structure of heterochromatin in two- to four-cell stage wild-type embryos, suggesting that CAF-1 is required for the maturation of heterochromatin during preimplantation development. In embryonic stem cells, depletion of p150CAF-1 using RNA interference results in the mislocalization, loss of clustering, and decondensation of pericentric heterochromatin domains. Furthermore, loss of CAF-1 in these cells results in the alteration of epigenetic histone methylation marks at the level of pericentric heterochromatin. These alterations of heterochromatin are not found in p150CAF-1-depleted mouse embryonic fibroblasts, which are cells that are already lineage committed, suggesting that CAF-1 is specifically required for heterochromatin organization in pluripotent embryonic cells. Our findings underline the role of the chromatin assembly machinery in controlling the spatial organization and epigenetic marking of the genome in early embryos and embryonic stem cells.     

Patterns of inflammation and the use of reversibility testing in smokers with airway complaints

Background

Although both smoking and respiratory complaints are very common, tools to improve diagnostic accuracy are scarce in primary care. This study aimed to reveal what inflammatory patterns prevail in clinically established diagnosis groups, and what factors are associated with eosinophilia.

Method

Induced sputum and blood plasma of 59 primary care patients with COPD (n = 17), asthma (n = 11), chronic bronchitis (CB, n = 14) and smokers with no respiratory complaints ('healthy smokers', n = 17) were collected, as well as lung function, smoking history and clinical work-up. Patterns of inflammatory markers per clinical diagnosis and factors associated with eosinophilia were analyzed by multiple regression analyses, the differences expressed in odds ratios (OR) with 95% confidence intervals.

Results

Multivariately, COPD was significantly associated with raised plasma-LBP (OR 1.2 [1.04–1.37]) and sTNF-R55 in sputum (OR 1.01 [1.001–1.01]), while HS expressed significantly lowered plasma-LBP (OR 0.8 [0.72–0.95]). Asthma was characterized by higher sputum eosinophilic counts (OR 1.3 [1.05–1.54]), while CB showed a significantly higher proportion of sputum lymphocytic counts (OR 1.5 [1.12–1.9]). Sputum eosinophilia was significantly associated with reversibility after adjusting for smoking, lung function, age, gender and allergy.

Conclusion

Patterns of inflammatory markers in a panel of blood plasma and sputum cells and mediators were discernable in clinical diagnosis groups of respiratory disease. COPD and so-called healthy smokers showed consistent opposite associations with plasma LBP, while chronic bronchitics showed relatively predominant lymphocytic inflammation compared to other diagnosis groups. Only sputum eosinophilia remained significantly associated with reversibility across the spectrum of respiratory disease in smokers with airway complaints.     

新型非病毒三元复合DNA载体的研究

基因治疗是未来临床医学最具潜力的治疗方式,目前阻碍临床基因治疗发展的主要因素是缺乏安全和高效的基因载体,因此研究理想的非病毒转基因载体具有重要的意义.构建了由质粒DNA(D)-抗DNA抗体(A)-阳离子脂质体(C)组成的三元复合纳米基因载体(DAC),研究表明,三组分在磷酸缓冲液中可通过分子组装形成复合纳米胶束,DAC在细胞培养中表现出显著高效的基因表达,DAC在血管平滑肌细胞中的基因转染效率比不含抗DNA抗体的二元组合(DC)高4倍,比不含阳离子脂质体的二元组合(DA)约高11倍.激光共聚焦荧光显微观察证明,DAC细胞摄取量和DNA进入细胞核的量均明显高于对照组,而DC二元组合(不含抗DNA抗体)的DNA很少进入细胞核,细胞在DAC存在下生长正常.未发现细胞毒性.研究结果提示,DAC的作用机理主要是三元复合胶束中DNA的装载量比二元载体大得多,抗DNA抗体与阳离子脂质体的协同作用明显有利于DNA被细胞摄取和胞吞,从而提高了基因的转染和表达.     

Protease inhibitors prevent plasminogen-mediated,but not pemphigus vulgaris-induced,acantholysis in human epidermis

Pemphigus is an autoimmune blistering disease of the skin and mucous membranes. It is caused by autoantibodies directed against desmosomes, which are the principal adhesion structures between epidermal keratinocytes. Binding of autoantibodies leads to the destruction of desmosomes resulting in the loss of cell-cell adhesion (acantholysis) and epidermal blisters. The plasminogen activator system has been implicated as a proteolytic effector in pemphigus. We have tested inhibitors of the plasminogen activator system with regard to their potential to prevent pemphigus-induced cutaneous pathology. In a human split skin culture system, IgG preparations of sera from pemphigus vulgaris patients caused histopathologic changes (acantholysis) similar to those observed in the original pemphigus disease. All inhibitors that were tested (active site inhibitors directed against uPA, tPA, and/or plasmin; antibodies neutralizing the enzymatic activity of uPA or tPA; substances interfering with the binding of uPA to its specific cell surface receptor uPAR) failed to prevent pemphigus vulgaris IgG-mediated acantholysis. Plasminogen-mediated acantholysis, however, was effectively antagonized by the synthetic active site serine protease inhibitor WX-UK1 or by p-aminomethylbenzoic acid. Our data argue against applying anti-plasminogen activator/anti-plasmin strategies in the management of pemphigus.