A Flexible, Quantitative Plasmonic-Fluor Lateral Flow Assay for the Rapid Detection of Orthoebolavirus zairense and Orthoebolavirus sudanense

Filoviruses comprise a family of single-stranded, negative-sense RNA viruses with a significant impact on human health. Given the risk for disease outbreaks, as highlighted by the recent outbreaks across Africa, there is an unmet need for flexible diagnostic technologies that can be deployed in resource-limited settings. Herein, we highlight the use of plasmonic-fluor lateral flow assays (PF-LFA) for the rapid, quantitative detection of an Ebolavirus-secreted glycoprotein, a marker for infection. Plasmonic fluors are a class of ultrabright reporter molecules that combine engineered nanorods with conventional fluorophores, resulting in improved analytical sensitivity. We have developed a PF-LFA for Orthoebolavirus zairense (EBOV) and Orthoebolavirus sudanense (SUDV) that provides estimated limits of detection as low as 0.446 and 0.641 ng/mL, respectively. Furthermore, our assay highlights a high degree of specificity between the two viral species while also maintaining a turnaround time as short as 30 min. To highlight the utility of our PF-LFA, we demonstrate the detection of EBOV infection in non-human primates. Our PF-LFA represents an enormous step forward in the development of a robust, field-deployable assay for filoviruses.

Long-term Prophylaxis Against Aerosolized Marburg Virus in Nonhuman Primates With an Afucosylated Monoclonal Antibody

Marburg virus (MARV) causes a hemorrhagic fever disease in human and nonhuman primates with high levels of morbidity and mortality. Concerns about weaponization of aerosolized MARV have spurred the development of nonhuman primate (NHP) models of aerosol exposure. To address the potential threat of aerosol exposure, a monoclonal antibody that binds MARV glycoprotein was tested, MR186YTE, for its efficacy as a prophylactic. MR186YTE was administered intramuscularly to NHPs at 15 or 5 mg/kg 1 month prior to MARV aerosol challenge. Seventy-five percent (3/4) of the 15 mg/kg dose group and 50% (2/4) of the 5 mg/kg dose group survived. Serum analyses showed that the NHP dosed with 15 mg/kg that succumbed to infection developed an antidrug antibody response and therefore had no detectable MR186YTE at the time of challenge. These results suggest that intramuscular dosing of mAbs may be a clinically useful prophylaxis for MARV aerosol exposure.

Development, women-centricity and psychometric properties of maternity patient-reported outcome measures (PROMs): A systematic review

BACKGROUND

Measuring maternity care outcomes based on what women value is critical to promoting woman-centred maternity care. Patient-reported outcome measures (PROMs) are instruments that enable service users to assess healthcare service and system performance.

AIM

To identify and critically appraise the risk of bias, woman-centricity (content validity) and psychometric properties of maternity PROMs published in the scientific literature.

METHODS

MEDLINE, CINAHL Plus, PsycINFO and Embase were systematically searched for relevant records between 01/01/2010 and 07/10/2021. Included articles underwent risk of bias, content validity and psychometric properties assessments in line with COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidance. PROM results were summarised according to language subgroups and an overall recommendation for use was determined.

FINDINGS

Forty-four studies reported on the development and psychometric evaluation of 9 maternity PROMs, grouped into 32 language subgroups. Risk of bias assessments for the PROM development and content validity showed inadequate or doubtful methodological quality. Internal consistency reliability, hypothesis testing (for construct validity), structural validity and test-retest reliability varied markedly in sufficiency and evidence quality. No PROMs received a level 'A' recommendation, required for real-world use.

CONCLUSION

Maternity PROMs identified in this systematic review had poor quality evidence for their measurement properties and lacked sufficient content validity, indicating a lack of woman-centricity in instrument development. Future research should prioritise women's voices in deciding what is relevant, comprehensive and comprehensible to measure, as this will impact overall validity and reliability and facilitate real-world use.

Universal DNA methylation age across mammalian tissues

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

Association between nonalcoholic fatty liver disease and carotid intima-media thickness

Background

Many non-invasive methods have been studied for assessing the severity of fatty liver disease and carotid intima-media thickness (CIMT). However, the correlation between hepatic steatosis and CIMT has not been fully studied, either globally or in Vietnam. This study investigated the association between nonalcoholic fatty liver disease (NAFLD) and CIMT.

Methods

A cross-sectional study was performed on 125 patients at the Cardiology Department, the Emergency Interventional Cardiology Department, and the Internal Cardiology Clinic of Thong Nhat Hospital.

Results

Among the 125 patients in our study population, NAFLD was diagnosed in 56%, and the mean CIMT was 0.89 ± 0.48 mm. Normal CIMT was measured in 21% of patients, whereas 79% had an elevated CIMT. The NAFLD rates were significantly different between patients with normal and increased CIMT, at 26.9% and 69.6%, respectively (p = 0.001).

Conclusions

Our study revealed a strong association between NAFLD and CIMT. NAFLD is currently considered a feature of metabolic syndrome, and an increase in the prevalence of NAFLD might result in an increase in the incidence of cardiovascular disease.

Detection of biomarkers for filoviral infection with a silicon photonic resonator platform

This protocol describes the use of silicon photonic microring resonator sensors for detection of Ebola virus (EBOV) and Sudan virus (SUDV) soluble glycoprotein (sGP). This protocol encompasses biosensor functionalization of silicon microring resonator chips, detection of protein biomarkers in sera, preparing calibration standards for analytical validation, and quantification of the results from these experiments. This protocol is readily adaptable toward other analytes, including cytokines, chemokines, nucleic acids, and viruses. For complete details on the use and execution of this protocol, please refer to Qavi et al. (2022).

Correlation between nonalcoholic fatty liver disease and coronary atherosclerosis

BACKGROUND

Various non-invasive methods have been studied for assessing the severity of fatty liver disease and coronary atherosclero-sis. However, the correlation between hepatic steatosis and coronary atherosclerosis has not been fully studied, either globally or specifically in Vietnam. This study investigated the association between nonalcoholic fatty liver disease (NAFLD) and coronary atherosclerosis using coronary computed tomography angiography (CCTA).

METHODS

An analytical cross-sectional study was performed, including 223 patients treated by the Cardiology Department, the Emergency Interventional Cardiology Departments, and the Internal Cardiology Clinic of Thong Nhat Hospital.

RESULTS

In our cohort of 223 patients, the NAFLD was detected in 66% of the population, the mean coronary artery stenosis (CAS) was 44.54% ± 20.23%, and the mean coronary artery calcium score (CACS) was 3569.05 ± 425.99, as assessed using the Agatston method. The proportion of patients with significant atherosclerotic plaque (CAS 50%) >was 32%, whereas the remaining 68% had insignificant stenosis. Among our study population, 16% had no coronary artery calcification, 38% had mild calcification, and 46% had moderate to severe calcification. In the group of NAFLD patients, 33.3% had significant atherosclerotic plaque, which was not significantly different from the rate in individuals without NAFLD (p = 0.51). Mild coronary artery calcification was detected in 37.4% of NAFLD patients, and moderate to severe calcification was detected in 48.3% (p = 0.45).

CONCLUSIONS

NAFLD was not found to be strongly associated with coronary atherosclerosis in this study. More studies with larger sample sizes remain necessary to verify whether any correlation exists.

Rapid detection of an Ebola biomarker with optical microring resonators

Ebola virus (EBOV) is a highly infectious pathogen, with a case mortality rate as high as 89%. Rapid therapeutic treatments and supportive measures can drastically improve patient outcome; however, the symptoms of EBOV disease (EVD) lack specificity from other endemic diseases. Given the high mortality and significant symptom overlap, there is a critical need for sensitive, rapid diagnostics for EVD. Facile diagnosis of EVD remains a challenge. Here, we describe a rapid and sensitive diagnostic for EVD through microring resonator sensors in conjunction with a unique biomarker of EBOV infection, soluble glycoprotein (sGP). Microring resonator sensors detected sGP in under 40 min with a limit of detection (LOD) as low as 1.00 ng/mL in serum. Furthermore, we validated our assay with the detection of sGP in serum from EBOV-infected non-human primates. Our results demonstrate the utility of a high-sensitivity diagnostic platform for detection of sGP for diagnosis of EVD.

Abstract 3402: BCAT1 as a druggable target in immuno-oncology

BCAT1, the enzyme responsible for the reversible transamination of leucine in the cytosol, has recently been implicated in the development and growth of various types of cancer. The limited expression of BCAT1 in adult tissues under physiological conditions suggests that the enzyme is a sensible target for drug development. To better understand the role of BCAT1 in cancer, we examined its gene expression at the single cell level (scRNAseq) in specimens obtained from lung, colorectal, breast, and ovarian cancer patients (n=36; >200,000 single cells). In those samples, Bcat1 gene expression was primarily associated with myeloid cells and fibroblasts with the exception of ovarian cancer in which robust Bcat1 presence was also seen in cancer cells. In tumor infiltrating lymphocytes (TILs), enrichment in Bcat1 gene expression was observed in exhausted CD4+ and CD8+ T cells compared to other T cell subtypes; this was independent of the cancer type examined. We speculated that inhibition of BCAT1 in TILs reverses exhaustion and has a therapeutic impact in cancer. In the syngeneic CT26 colon cancer model, combination treatment of a BCAT1 inhibitor (ERG245; ip administration of 5 mg/kg, given at days 7, 8 and 9 after tumor cell inoculation) and an anti-PD1 antibody (ab) (clone RMP1-14; ip administration given at days 7, 11, 14, and 18) led to eradication of established tumors. In the same model, limited treatment of large tumors (average size of ~600 mm3) with ERG245+anti-PD1 ab suppressed tumor growth and increased the frequency of CD8+ T cells expressing Granzyme B and IFNγ by ~50% compared to anti-PD1 monotherapy. Mechanistically, in vitro treatment of newly activated hCD8+ T cells with ERG245 impaired translocation of the lactate transporter MCT1 to the cell surface and increased the levels of intracellular lactate within 30 min of activation leading to upregulation of transcription factor ATF3. ERG245-driven metabolic reprogramming of CD8+ T cells towards an oxidative phenotype (increased OXPHOS) was also observed at 24h of treatment. Withdrawal of ERG245 restored intracellular lactate levels without reversing the metabolic reprogramming of the cells. We propose that these are elements of a mechanism that links temporal inhibition of BCAT1 to the rise of highly energetic CD8+ T cells with increased cytotoxicity and proliferative capacity in vitro and in vivo.

Citation Format: Adonia E. Papathanassiu, Francesca Lodi, Hagar Elkafrawy, Michelangelo Certo, Hong Vu, Jeong Hun Ko, Jacques Behmoaras, Claudio Mauro, Diether Lambrechts. BCAT1 as a druggable target in immuno-oncology [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3402.

A Device to Predict Short-Term Healing Outcome of Chronic Wounds

Objective: While myriads of studies have suggested that a survey of wound pH environment could indicate wound healing activities, it is not clear whether wound alkalinity can be used as a prognostic indicator of nonhealing wounds. Currently available systems cannot reliably assess the pH environment across wounds, which is the objective of this study. Approach: A disposable device, DETEC® pH, was developed and characterized on its ability to map wound alkalinity by pressing a freshly recovered wound dressing against its test surface. By comparing the wound's alkalinity and size reduction rates (∼7 days) following pH measurement, we assessed the capability of wound alkalinity to prognosticate subsequent short-term wound size reduction rates. Results: The device had high accuracy and specificity in determining the alkalinity of simulated wound fluids soaked onto wound dressing. The type of wound dressing type had an insignificant effect on its detection sensitivity. Upon testing discarded wound dressings from human patients, the device quickly determined alkaline and acidic wounds. Finally, statistical analyses of wound size reduction rates in wounds with various alkalinities confirmed that wound alkalinity has a strong influence on, at least, short-term wound healing activity. Innovation: Without directly contacting the patient, this device provides a quick assessment of wound alkalinity to prognosticate immediate and short-term wound healing activities. Conclusion: DETEC® pH may serve as a prognosis device for wound care specialists during routine wound assessment to predict wound healing progress. This information can assist the decision-making process in a clinical setting and augur well for chronic wound treatment. DETEC® pH can also be used as an aid for home health care nurses or health care providers to screen nonhealing wounds outside clinics.

A near-infrared fluorescent pH sensing film for wound milieu pH monitoring

Studies have shown that wound pH is a potentially influential factor in the healing process. Due to the flaws of traditional pH measurement approaches, wound pH measurement has not become part of current standard of care. A near-infrared pH-sensitive ratiometric film was created and characterized for measuring wound pH. This film was fabricated by physically absorbing poly (N-isopropyl Acrylamide) nanoparticles conjugated with pH-sensitive (CypHer5E) and pH-insensitive (Cy7) fluorescent dyes into 2-hydroxyethyl methacrylate hydrogel film. The pH pattern on wounds can be indirectly measured by pressing freshly discarded wound dressing on top of the pH-sensitive film and imaging it. In vitro tests show that the film can accurately and rapidly detect a wide range of pH (from pH 4 to 8) in wound milieu. Further, patient studies showed that, by measuring pH on wound contact side of discarded wound gauze, the pH and its non-homogeneous distribution on wounds can be indirectly determined. By comparing patients with different wound conditions, we find that near-infrared pH sensing film can be used to measure wound exudate pH with high accuracy and efficiency. In addition, wound pH determination can provide an accurate assessment of wound healing activity in real time.

Efficacy of Ebola Glycoprotein-Specific Equine Polyclonal Antibody Product Against Lethal Ebola Virus Infection in Guinea Pigs

Background

Filoviruses including Ebola, Sudan, and other species are emerging zoonotic pathogens representing a significant public health concern with high outbreak potential, and they remain a potential bioterrorism-related threat. We have developed a despeciated equine Ebola polyclonal antibody (E-EIG) postexposure treatment against Ebola virus (EBOV) and evaluated its efficacy in the guinea pig model of EBOV infection.

Methods

Guinea pigs were infected with guinea pig-adapted EBOV (Mayinga strain) and treated with various dose levels of E-EIG (20-100 mg/kg) twice daily for 6 days starting at 24 h postinfection. The E-EIG was also assessed for neutralization activity against related filoviruses including EBOV strains Mayinga, Kikwit, and Makona and the Bundibugyo and Taï Forest ebolavirus species.

Results

Treatment with E-EIG conferred 83% to 100% protection in guinea pigs. The results demonstrated a comparable neutralization activity (range, 1:512-1:896) of E-EIG against all tested strains, suggesting the potential for cross-protection with the polyclonal antibody therapeutic.

Conclusions

This study showed that equine-derived polyclonal antibodies are efficacious against lethal EBOV disease in a relevant animal model. Furthermore, the studies support the utility of the equine antibody platform for the rapid production of a therapeutic product in the event of an outbreak by a filovirus or other zoonotic pathogen.

Development of a dual-wavelength fluorescent nanoprobe for in vivo and in vitro cell tracking consecutively

Many imaging probes have been developed for a wide variety of imaging modalities. However, no optical imaging probe could be utilized for both microscopic and whole animal imaging. To fill the gap, the dual-wavelength fluorescent imaging nanoprobe was developed to simultaneously carry both visible-range fluorescent dye and near-infrared (NIR) dye. Emission scan confirms that the nanoprobe exhibits two separate peaks with strong fluorescent intensity in both visible and NIR ranges. Furthermore, the dual-wavelength fluorescent nanoprobe has high photostability and colloidal stability, as well as long shelf-life. In vitro cell culture experiments show that the nanoprobe has the ability to label different types of cells (namely, esophageal, prostate, fibroblast and macrophage cell) for fluorescent microscope imaging. More importantly, cell tracking experiments confirm that cell migration and distribution in various organs can be tracked in real time using in vivo whole-body NIR imaging and in vitro microscopic imaging, respectively.

Role of Antibodies in Protection Against Ebola Virus in Nonhuman Primates Immunized With Three Vaccine Platforms

Background

Several vaccine platforms have been successfully evaluated for prevention of Ebola virus (EBOV) disease (EVD) in nonhuman primates and humans. Despite remarkable efficacy by multiple vaccines, the immunological correlates of protection against EVD are incompletely understood.

Methods

We systematically evaluated the antibody response to various EBOV proteins in 79 nonhuman primates vaccinated with various EBOV vaccine platforms. We evaluated the serum immunoglobulin (Ig)G titers against EBOV glycoprotein (GP), the ability of the vaccine-induced antibodies to bind GP at acidic pH or to displace ZMapp, and virus neutralization titers. The correlation of these outcomes with survival from EVD was evaluated by appropriate statistical methods.

Results

Irrespective of the vaccine platform, protection from EVD strongly correlated with anti-GP IgG titers. The GP-directed antibody levels required for protection in animals vaccinated with virus-like particles (VLPs) lacking nucleoprotein (NP) was significantly higher than animals immunized with NP-containing VLPs or adenovirus-expressed GP, platforms that induce strong T-cell responses. Furthermore, protective immune responses correlated with anti-GP antibody binding strength at acidic pH, neutralization of GP-expressing pseudovirions, and the ability to displace ZMapp components from GP.

Conclusions

These findings suggest key quantitative and qualitative attributes of antibody response to EVD vaccines as potential correlates of protection.

Pan-filovirus monoclonal antibody cocktail protects against lethal challenge with Marburg virus in non-human primates

While disregarded in the past, the use of antibody therapeutics in the treatment of filovirus infection has been gaining traction in recent years. Early studies in our lab with the treatment of non-human primates (NHPs) with polyclonal antibodies from convalescent NHPs demonstrated protection against challenges with a lethal dose of Ebola virus (EBOV). Successes with monoclonal antibody (mAb) cocktails such as ZMapp™ have encouraged the development of a cocktail that may be protective against multiple species of filovirus. This may ultimately allow for the prepositioning of a single cocktail in filovirus prone locations, rather than storing and maintaining multiple cocktails at each location. We have previously described three antibodies, FVM04 and CA45, which can neutralize multiple species of ebolavirus, and MR191, which can neutralize marburgviruses, and have shown efficacy in rodent and NHP models of filovirus disease. In this study, we evaluated the efficacy of a pan-ebolavirus cocktail (FVM04+CA45) in combination with the Marburg virus specific mAb MR191 in a pan-filovirus cocktail (FVM04+CA45+MR191), in the NHP model of Marburg virus disease. Both the pan-ebolavirus and pan-filovirus cocktails have been shown to be efficacious against lethal challenge with Sudan virus (SUDV) or EBOV in the rhesus macaque model. These data are the first to demonstrate protective efficacy of MR191 as part of a pan-filovirus cocktail against MARV in the NHP model of disease.

Immunization-Elicited Broadly Protective Antibody Reveals Ebolavirus Fusion Loop as a Site of Vulnerability

While neutralizing antibodies are highly effective against ebolavirus infections, current experimental ebolavirus vaccines primarily elicit species-specific antibody responses. Here, we describe an immunization-elicited macaque antibody (CA45) that clamps the internal fusion loop with the N terminus of the ebolavirus glycoproteins (GPs) and potently neutralizes Ebola, Sudan, Bundibugyo, and Reston viruses. CA45, alone or in combination with an antibody that blocks receptor binding, provided full protection against all pathogenic ebolaviruses in mice, guinea pigs, and ferrets. Analysis of memory B cells from the immunized macaque suggests that elicitation of broadly neutralizing antibodies (bNAbs) for ebolaviruses is possible but difficult, potentially due to the rarity of bNAb clones and their precursors. Unexpectedly, germline-reverted CA45, while exhibiting negligible binding to full-length GP, bound a proteolytically remodeled GP with picomolar affinity, suggesting that engineered ebolavirus vaccines could trigger rare bNAb precursors more robustly. These findings have important implications for developing pan-ebolavirus vaccine and immunotherapeutic cocktails.

Cooperativity Enables Non-neutralizing Antibodies to Neutralize Ebolavirus

Drug combinations are synergistic when their combined efficacy exceeds the sum of the individual actions, but they rarely include ineffective drugs that become effective only in combination. We identified several “enabling pairs” of neutralizing and non-neutralizing anti-ebolavirus monoclonal antibodies, whose combination exhibited new functional profiles, including transforming a non-neutralizing antibody to a neutralizer. Sub-neutralizing concentrations of antibodies 2G4 or m8C4 enabled non-neutralizing antibody FVM09 (IC₅₀ >1 μM) to exhibit potent neutralization (IC₅₀ 1–10 nM). While FVM09 or m8C4 alone failed to protect Ebola-virus-infected mice, a combination of the two antibodies provided 100% protection. Furthermore, non-neutralizers FVM09 and FVM02 exponentially enhanced the potency of two neutralizing antibodies against both Ebola and Sudan viruses. We identified a hotspot for the binding of these enabling antibody pairs near the interface of the glycan cap and GP2. Enabling cooperativity may be an underappreciated phenomenon for viruses, with implications for the design and development of immunotherapeutics and vaccines.

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We describe cooperative neutralization and in vivo protection

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Cooperativity turns non-neutralizing ebolavirus antibodies into potent neutralizers

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A hotspot for antibody cooperativity identified on Ebola virus glycoprotein

Antibody Treatment of Ebola and Sudan Virus Infection via a Uniquely Exposed Epitope within the Glycoprotein Receptor-Binding Site

Previous efforts to identify cross-neutralizing antibodies to the receptor-binding site (RBS) of ebolavirus glycoproteins have been unsuccessful, largely because the RBS is occluded on the viral surface. We report a monoclonal antibody (FVM04) that targets a uniquely exposed epitope within the RBS; cross-neutralizes Ebola (EBOV), Sudan (SUDV), and, to a lesser extent, Bundibugyo viruses; and shows protection against EBOV and SUDV in mice and guinea pigs. The antibody cocktail ZMapp™ is remarkably effective against EBOV (Zaire) but does not cross-neutralize other ebolaviruses. By replacing one of the ZMapp™ components with FVM04, we retained the anti-EBOV efficacy while extending the breadth of protection to SUDV, thereby generating a cross-protective antibody cocktail. In addition, we report several mutations at the base of the ebolavirus glycoprotein that enhance the binding of FVM04 and other cross-reactive antibodies. These findings have important implications for pan-ebolavirus vaccine development and defining broadly protective antibody cocktails.

Virus-Like Particle Vaccination Protects Nonhuman Primates from Lethal Aerosol Exposure with Marburgvirus (VLP Vaccination Protects Macaques against Aerosol Challenges)

Marburg virus (MARV) was the first filovirus to be identified following an outbreak of viral hemorrhagic fever disease in Marburg, Germany in 1967. Due to several factors inherent to filoviruses, they are considered a potential bioweapon that could be disseminated via an aerosol route. Previous studies demonstrated that MARV virus-like particles (VLPs) containing the glycoprotein (GP), matrix protein VP40 and nucleoprotein (NP) generated using a baculovirus/insect cell expression system could protect macaques from subcutaneous (SQ) challenge with multiple species of marburgviruses. In the current study, the protective efficacy of the MARV VLPs in conjunction with two different adjuvants: QS-21, a saponin derivative, and poly I:C against homologous aerosol challenge was assessed in cynomolgus macaques. Antibody responses against the GP antigen were equivalent in all groups receiving MARV VLPs irrespective of the adjuvant; adjuvant only-vaccinated macaques did not demonstrate appreciable antibody responses. All macaques were subsequently challenged with lethal doses of MARV via aerosol or SQ as a positive control. All MARV VLP-vaccinated macaques survived either aerosol or SQ challenge while animals administered adjuvant only exhibited clinical signs and lesions consistent with MARV disease and were euthanized after meeting the predetermined criteria. Therefore, MARV VLPs induce IgG antibodies recognizing MARV GP and VP40 and protect cynomolgus macaques from an otherwise lethal aerosol exposure with MARV.

Quantitative serology assays for determination of antibody responses to Ebola virus glycoprotein and matrix protein in nonhuman primates and humans

The West Africa Ebola virus disease (EVD) outbreak has reached unprecedented magnitude and caused worldwide concerns for the spread of this deadly virus. Recent findings in nonhuman primates (NHPs) demonstrate that antibodies can be protective against EVD. However, the role of antibody response in vaccine-mediated protection is not fully understood. To address these questions quantitative serology assays are needed for measurement of the antibody response to key Ebola virus (EBOV) proteins. Serology enzyme-linked immunosorbent assays (ELISA's), using a reference detection antibody, were developed in order to standardize the quantitation of antibody levels in vaccinated NHPs or in humans exposed to EBOV or immunized with an EBOV vaccine. Critical reagents were generated to support the development of the serology ELISAs. Recombinant EBOV matrix protein (VP40) was expressed in Escherichia coli and purified. Two variants of the glycoprotein (GP), the ectodomain lacking the transmembrane domain (GPΔTM), and an engineered GP lacking the mucin-like domain (GPΔmuc) were expressed and purified from mammalian cell systems. Using these proteins, three ELISA methods were developed and optimized for reproducibility and robustness, including stability testing of critical reagents. The assay was used to determine the antibody response against VP40, GPΔTM, and GPΔmuc in a NHP vaccine study using EBOV virus-like particles (VLP) vaccine expressing GP, VP40 and the nucleoprotein. Additionally, these ELISAs were used to successfully detect antibody responses to VP40, GPΔTM and GPΔmuc in human sera from EBOV infected individuals.

Homologous and heterologous protection of nonhuman primates by Ebola and Sudan virus-like particles

Filoviruses cause hemorrhagic fever resulting in significant morbidity and mortality in humans. Several vaccine platforms that include multiple virus-vectored approaches and virus-like particles (VLPs) have shown efficacy in nonhuman primates. Previous studies have shown protection of cynomolgus macaques against homologous infection for Ebola virus (EBOV) and Marburg virus (MARV) following a three-dose vaccine regimen of EBOV or MARV VLPs, as well as heterologous protection against Ravn Virus (RAVV) following vaccination with MARV VLPs. The objectives of the current studies were to determine the minimum number of vaccine doses required for protection (using EBOV as the test system) and then demonstrate protection against Sudan virus (SUDV) and Taï Forest virus (TAFV). Using the EBOV nonhuman primate model, we show that one or two doses of VLP vaccine can confer protection from lethal infection. VLPs containing the SUDV glycoprotein, nucleoprotein and VP40 matrix protein provide complete protection against lethal SUDV infection in macaques. Finally, we demonstrate protective efficacy mediated by EBOV, but not SUDV, VLPs against TAFV; this is the first demonstration of complete cross-filovirus protection using a single component heterologous vaccine within the Ebolavirus genus. Along with our previous results, this observation provides strong evidence that it will be possible to develop and administer a broad-spectrum VLP-based vaccine that will protect against multiple filoviruses by combining only three EBOV, SUDV and MARV components.

Structurally designed attenuated subunit vaccines for S. aureus LukS-PV and LukF-PV confer protection in a mouse bacteremia model

Previous efforts towards S. aureus vaccine development have largely focused on cell surface antigens to induce opsonophagocytic killing aimed at providing sterile immunity, a concept successfully applied to other Gram-positive pathogens such as Streptococcus pneumoniae. However, these approaches have largely failed, possibly in part due to the remarkable diversity of the staphylococcal virulence factors such as secreted immunosuppressive and tissue destructive toxins. S. aureus produces several pore-forming toxins including the single subunit alpha hemolysin as well as bicomponent leukotoxins such as Panton-Valentine leukocidin (PVL), gamma hemolysins (Hlg), and LukED. Here we report the generation of highly attenuated mutants of PVL subunits LukS-PV and LukF-PV that were rationally designed, based on an octameric structural model of the toxin, to be deficient in oligomerization. The attenuated subunit vaccines were highly immunogenic and showed significant protection in a mouse model of S. aureus USA300 sepsis. Protection against sepsis was also demonstrated by passive transfer of rabbit immunoglobulin raised against LukS-PV. Antibodies to LukS-PV inhibited the homologous oligomerization of LukS-PV with LukF-PV as well heterologous oligomerization with HlgB. Importantly, immune sera from mice vaccinated with the LukS mutant not only inhibited the PMN lytic activity produced by the PVL-positive USA300 but also blocked PMN lysis induced by supernatants of PVL-negative strains suggesting a broad protective activity towards other bicomponent toxins. These findings strongly support the novel concept of an anti-virulence, toxin-based vaccine intended for prevention of clinical S. aureus invasive disease, rather than achieving sterile immunity. Such a multivalent vaccine may include attenuated leukotoxins, alpha hemolysin, and superantigens.

Novel structurally designed vaccine for S. aureus α-hemolysin: protection against bacteremia and pneumonia

Staphylococcus aureus (S. aureus) is a human pathogen associated with skin and soft tissue infections (SSTI) and life threatening sepsis and pneumonia. Efforts to develop effective vaccines against S. aureus have been largely unsuccessful, in part due to the variety of virulence factors produced by this organism. S. aureus alpha-hemolysin (Hla) is a pore-forming toxin expressed by most S. aureus strains and reported to play a key role in the pathogenesis of SSTI and pneumonia. Here we report a novel recombinant subunit vaccine candidate for Hla, rationally designed based on the heptameric crystal structure. This vaccine candidate, denoted AT-62aa, was tested in pneumonia and bacteremia infection models using S. aureus strain Newman and the pandemic strain USA300 (LAC). Significant protection from lethal bacteremia/sepsis and pneumonia was observed upon vaccination with AT-62aa along with a Glucopyranosyl Lipid Adjuvant-Stable Emulsion (GLA-SE) that is currently in clinical trials. Passive transfer of rabbit immunoglobulin against AT-62aa (AT62-IgG) protected mice against intraperitoneal and intranasal challenge with USA300 and produced significant reduction in bacterial burden in blood, spleen, kidney, and lungs. Our Hla-based vaccine is the first to be reported to reduce bacterial dissemination and to provide protection in a sepsis model of S. aureus infection. AT62-IgG and sera from vaccinated mice effectively neutralized the toxin in vitro and AT62-IgG inhibited the formation of Hla heptamers, suggesting antibody-mediated neutralization as the primary mechanism of action. This remarkable efficacy makes this Hla-based vaccine a prime candidate for inclusion in future multivalent S. aureus vaccine. Furthermore, identification of protective epitopes within AT-62aa could lead to novel immunotherapy for S. aureus infection.

Latitudinal variation in top-down and bottom-up control of a salt marsh food web

The shrub Iva frutescens, which occupies the terrestrial border of U.S. Atlantic Coast salt marshes, supports a food web that varies strongly across latitude. We tested whether latitudinal variation in plant quality (higher at high latitudes), consumption by omnivores (a crab, present only at low latitudes), consumption by mesopredators (ladybugs, present at all latitudes), or the life history stage of an herbivorous beetle could explain continental-scale field patterns of herbivore density. In a mesocosm experiment, crabs exerted strong top-down control on herbivorous beetles, ladybugs exerted strong top-down control on aphids, and both predators benefited plants through trophic cascades. Latitude of plant origin had no effect on consumers. Herbivorous beetle density was greater if mesocosms were stocked with beetle adults rather than larvae, and aphid densities were reduced in the "adult beetle" treatment. Treatment combinations representing high and low latitudes produced patterns of herbivore density similar to those in the field. We conclude that latitudinal variation in plant quality is less important than latitudinal variation in top consumers and competition in mediating food web structure. Climate may also play a strong role in structuring high-latitude salt marshes by limiting the number of herbivore generations per growing season and causing high overwintering mortality.

Does combined multichannel intraluminal esophageal impedance and manometry predict postoperative dysphagia after laparoscopic Nissen fundoplication?

Laparoscopic Nissen fundoplication (LNF) is an effective treatment for gastroesophageal reflux disease; however, some patients develop dysphagia postoperatively. Manometry is used to evaluate disorders of peristalsis, but has not been proven useful to identify which patients may be at risk for postoperative dysphagia. Multichannel intraluminal impedance (MII) evaluates the effective clearance of a swallowed bolus through the esophagus. We hypothesized that MII combined with manometry may detect those patients most at risk of developing dysphagia after LNF. Between March 2003 and January 2007, 74 patients who agreed to participate in this study were prospectively enrolled. All patients completed a preoperative symptom questionnaire, MII/manometry, and 24-h pH monitoring. All patients underwent LNF. Symptom questionnaires were administered postoperatively at a median of 18 months (range: 6-46 months), and we defined dysphagia (both preoperatively and postoperatively) as occurring more than once a month with a severity >or=4 (0-10 Symptom Severity Index). Thirty-two patients (43%) reported preoperative dysphagia, but there was no significant difference in pH monitoring, lower esophageal sphincter pressure/relaxation, peristalsis, liquid or viscous bolus transit (MII), or bolus transit time (MII) between patients with and without preoperative dysphagia. In those patients reporting preoperative dysphagia, the severity of dysphagia improved significantly from 6.8 +/- 2 to 2.6 +/- 3.4 (P < 0.001) after LNF. Thirteen (17%) patients reported dysphagia postoperatively, 10 of whom (75%) reported some degree of preoperative dysphagia. The presence of postoperative dysphagia was significantly more common in patients with preoperative dysphagia (P= 0.01). Patients with postoperative dysphagia had similar lower esophageal sphincter pressure and relaxation, peristalsis, and esophageal clearance to those without dysphagia. Neither MII nor manometry predicts dysphagia in patients with gastroesophageal reflux disease or its occurrence after LNF. The presence of dysphagia preoperatively is the only predictor of dysphagia after LNF.

The fibroblast growth factor-inducible 14 receptor is highly expressed in HER2-positive breast tumors and regulates breast cancer cell invasive capacity

Genomic characterization is beginning to define a molecular taxonomy for breast cancer; however, the molecular basis of invasion and metastasis remains poorly understood. We report a pivotal role for the fibroblast growth factor-inducible 14 (Fn14) receptor in this process. We examined whether Fn14 and its ligand tumor necrosis factor-like weak inducer of apoptosis (TWEAK) were expressed in breast tumors and whether deregulation of Fn14 levels affected malignant behavior of breast cancer cell lines. Analysis of TWEAK and Fn14 in publicly available gene expression data indicated that high Fn14 expression levels significantly correlated with several poor prognostic indicators (P < 0.05). Fn14 expression was highest in the HER2-positive/estrogen receptor-negative (HER2(+)/ER(-)) intrinsic subtype (P = 0.0008). An association between Fn14 and HER2 expression in breast tumors was confirmed by immunohistochemistry. Fn14 levels were elevated in invasive, ER(-) breast cancer cell lines. Overexpression of Fn14 in weakly invasive MCF7 and T47D cells resulted in a marked induction of invasion and activation of nuclear factor-kappaB (NF-kappaB) signaling. Ectopic expression of Fn14tCT, a Fn14 deletion mutant that cannot activate NF-kappaB signaling, was not able to induce invasion. Moreover, ectopic expression of Fn14tCT in highly invasive MDA-MB-231 cells reduced their invasive capability. RNA interference-mediated inhibition of Fn14 expression in both MDA-MB-231 and MDA-MB-436 cells reduced invasion. Expression profiling of the Fn14-depleted cells revealed deregulation of NF-kappaB activity. Our findings support a role for Fn14-mediated NF-kappaB pathway activation in breast tumor invasion and metastasis.

Transcutaneous delivery and thermostability of a dry trivalent inactivated influenza vaccine patch

A patch containing a trivalent inactivated influenza vaccine (TIV) was prepared in a dried, stabilized formulation for transcutaneous delivery. When used in a guinea pig immunogenicity model, the dry patch was as effective as a wet TIV patch in inducing serum anti-influenza IgG antibodies. When the dry TIV patch was administered with LT as an adjuvant, a robust immune response was obtained that was comparable with or better than an injected TIV vaccine. When stored sealed in a nitrogen-purged foil, the dry TIV patch was stable for 12 months, as measured by HA content, under both refrigerated and room temperature conditions. Moreover, the immunological potency of the vaccine product was not affected by long-term storage. The dry TIV patch was also thermostable against three cycles of alternating low-to-high temperatures of -20/25 and -20/40 degrees C, and under short-term temperature stress conditions. These studies indicate that the dry TIV patch product can tolerate unexpected environmental stresses that may be encountered during shipping and distribution. Because of its effectiveness in vaccine delivery and its superior thermostable characteristics, the dry TIV patch represents a major advance for needle-free influenza vaccination.

A diagnosis support system for capsule endoscopy

The diagnostic time required for a full, 8-hour video capsule endoscopy is usually between 45 and 120 min. The aim of this work is to evaluate the diagnostic time required when applying a method that adaptively controlls the image display rate. The advantage of the method is that the sequence can be played at high speed in stable smooth sequences to save time and then decreased at sequences where there are sudden rough changes, in order to assess suspicious findings detail. In this paper, this method is examined under real conditions: 10 sequences were independently evaluated by 4 medical doctors. The methods of evaluation include: 1) the time required for reading a sequence, 2) the percentage of abnormal regions accurately found, and 3) the manipulations of the evaluating physicians. The results indicate that the proposed method reduces diagnostic time to around 10 +/- 1.5% length of the sequence and is of valuable assistance to medical doctors.

TWEAK binding to the Fn14 cysteine-rich domain depends on charged residues located in both the A1 and D2 modules

TWEAK [TNF (tumour necrosis factor)-like weak inducer of apoptosis] is a member of the TNF superfamily of cytokines. TWEAK binds with high affinity to a single TNF receptor super-family member, Fn14 (fibroblast growth factor-inducible 14). This interaction can stimulate a variety of biological responses, depending on the cell type analysed. The murine Fn14 extracellular region is only 53 amino acids in length and primarily consists of a CRD (cysteine-rich domain) containing three disulphide bonds. In the present study, we investigated whether TWEAK binding to this CRD was dependent on selected evolutionarily conserved amino acid residues by using a site-specific mutagenesis approach and several different ligand-binding assays. Our results indicate that three residues within the predicted Fn14 CRD A1 module (Asp45, Lys48 and Met50) and one residue within the predicted D2 module (Asp62) are each critical for high-affinity TWEAK binding. Mutation of the three charged polar residues Asp45, Lys48 and Asp62 had the greatest deleterious effect, suggesting that electrostatic interactions between TWEAK and Fn14 residues may be particularly important for complex formation or stability. To determine whether the four critical residues were likely to be located on the Fn14 CRD surface, we made an Fn14 homology model based on a previously derived X-ray structure for the B-cell maturation antigen receptor, which also contains only one CRD. This model revealed that each of these critical residues were in areas of the receptor that are potentially capable of interacting with TWEAK. These results indicate that the TWEAK-Fn14 interaction is highly dependent on multiple Fn14 residues located in both CRD modules.

Soluble tumor necrosis factor-like weak inducer of apoptosis overexpression in HEK293 cells promotes tumor growth and angiogenesis in athymic nude mice

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is a member of the tumor necrosis factor superfamily of structurally related cytokines. TWEAK acts on responsive cells via binding to a cell surface receptor named Fn14. Recent studies have demonstrated that TWEAK can stimulate numerous cellular responses including cell proliferation, migration, and proinflammatory molecule production. It has also been reported that TWEAK can stimulate blood vessel formation in the rat cornea angiogenesis assay, but it is presently unknown whether this cytokine could play a role in the pathological angiogenesis associated with human diseases such as cancer, rheumatoid arthritis, and diabetic retinopathy. In the present study we investigated whether TWEAK was expressed in human tumors and whether it could promote tumor growth and angiogenesis in vivo. TWEAK mRNA expression was detected in many tumor types by cDNA array hybridization analysis, and TWEAK protein expression was confirmed in human colon cancer tissue by immunohistochemistry. As an initial approach to address whether TWEAK might act as a tumor angiogenesis factor, we established several human embryonic kidney cell lines that constitutively secrete a soluble TWEAK protein and examined their growth properties in vitro and in vivo. We found that although TWEAK-overexpressing cells do not have a growth advantage in vitro, they form larger and more highly vascularized tumors in athymic mice when compared with control, vector-transfected cells. This result suggests that the TWEAK-Fn14 signaling system may be a potential regulator of human tumorigenesis.

On the role of the starved codon and the takeoff site in ribosome bypassing in Escherichia coli

Translating ribosomes can skip over stretches of messenger RNA and resume protein chain elongation after a "bypassed" region. We have previously shown that limitation for isoleucyl-tRNA can initiate a ribosome bypass when an AUA codon is in the ribosomal A-site. We have now generalized this effect to other "hungry" codons calling for four different limiting aminoacyl-tRNA species, suggesting that a pause at any A-site will have this effect. We have assessed bypassing in a large family of reporters with nearly every different triplet in the "takeoff site", i.e. the P-site on the 5' side of the hungry codon, and an identical "landing site" codon 16 nucleotides downstream. The different takeoff sites vary over a factor of 50 in bypassing proficiency. At least part of this variation appears to reflect stability of the codon Colon, two colons anticodon interaction at the takeoff site, as indicated by the following: (a) the bypassing proficiency of different tRNAs shows a rough correlation with the frequency of A Colon, two colons U as opposed to G Colon, two colons C pairs in the codon Colon, two colons anticodon association; (b) specific tRNAs bypass more frequently from codons ending in U than from their synonym ending in C; (c) an arginine tRNA with Inosine in the wobble position which reads CGU, CGC, and CGA bypasses much more frequently from the last codon than the first two synonyms.

Recombinant prostate specific antigen inhibits angiogenesis in vitro and in vivo

BACKGROUND

Prostate specific antigen (PSA) is a kallikrein family member with serine protease activity commonly used as a diagnostic marker for prostate cancer. We recently described anti-angiogenic properties of PSA [Fortier et al.: JNCI 91:1635-1640].

METHODS

Two forms of PSA were cloned and expressed in Pichia pastoris: one, an intact PSA with an N-terminus of IVGGVS em leader; the second, an N-1 PSA variant. The recombinant proteins were tested for serine protease activity and for anti-angiogenic activity in vitro and in vivo.

RESULTS

The rate of substrate hydrolysis by the intact recombinant PSA was similar to that of PSA isolated and purified from human seminal plasma. In contrast, the N-1 PSA variant lacked serine protease activity. In an endothelial cell migration assay, the concentration that resulted in 50% inhibition (IC(50)) was: 0.5 microM for native PSA, 0.5 microM for intact recombinant protein, and 0.1 microM for the N-1 variant PSA. Both the intact recombinant and the N-1 recombinant PSA inhibited angiogenesis in vivo.

CONCLUSIONS

Purified recombinant PSA inhibits angiogenesis, proving the concept that PSA is an anti-angiogenic, and serine protease activity, as determined by synthetic substrate hydrolysis, is distinct from the anti-angiogenic properties of PSA.

Infant sleeping position and the risk of sudden infant death syndrome in California, 1997-2000

To assess the association between infant sleeping position and risk of sudden infant death syndrome (SIDS) in an ethnically diverse US population, the authors conducted a population-based case-control study in 11 counties in California from May 1997 through April 2000. The authors conducted in-person interviews with the mothers of 185 SIDS cases and 312 randomly selected race/ethnicity- and age-matched controls to collect information on sleeping positions. Infants who had last been put down to sleep in the prone or side position were at greater risk of SIDS than were infants who had last been put down on their backs (adjusted odds ratio (AOR) = 2.6 (95% confidence interval (CI): 1.5, 4.5) and AOR = 2.0 (95% CI: 1.2, 3.4) for the prone and side positions, respectively). The risk of SIDS was especially high for an unstable side position in which an infant was placed on its side and found prone (AOR = 8.7, 95% CI: 3.3, 22.7). Infants who were usually placed on their backs to sleep but had last been put down in the prone or side position (an unaccustomed position) had a significantly high risk of SIDS (AOR = 8.2 (95% CI: 2.6, 26.0) and AOR = 6.9 (95% CI: 2.3, 20.6) for the prone and side positions, respectively). Infants placed in an unaccustomed prone or side sleeping position had a higher risk of SIDS than infants who were always placed prone or on the side.

Diagnosis of malignant granular cell tumor by fine needle aspiration cytology:

BACKGROUND

Malignant granular cell tumors (GCT) are the rarest of all sarcomas, and the histologic differentiation from their benign counterpart may be extremely difficult or impossible unless metastatic disease is demonstrated. To our knowledge, this is the first report of a malignant GCT diagnosed by fine needle aspiration (FNA) cytology.

CASE

A 70-year-old, Caucasian female presented with a progressively enlarging left supraclavicular mass. FNA of the mass revealed a metastatic tumor cytologically consistent with GCT. With this diagnosis, a search for other metastatic sites was initiated. Computed tomography (CT) scan revealed several tumor nodules in the lungs and liver. CT-guided FNA and tru-cut needle biopsy of a liver mass confirmed the diagnosis of metastatic GCT. In searching for a primary site, the patient revealed a clinical history of having had a tumor removed from her back two months before; it was reported to be an atypical GCT. Comparison of the three tumors revealed similar histologic, cytologic and immunohistochemical features.

CONCLUSION

Evidence of mild to moderate cytologic atypia; increased mitotic activity; locally aggressive growth; increased proliferative activity as demonstrated by immunohistochemical evaluation of proliferation markers; and DNA ploidy analysis, as reported for this case, may be helpful in predicting malignant behavior of GCTs.