Kupyaphores are zinc homeostatic metallophores required for colonization of Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb) endures a combination of metal scarcity and toxicity throughout the human infection cycle, contributing to complex clinical manifestations. Pathogens counteract this paradoxical dysmetallostasis by producing specialized metal trafficking systems. Capture of extracellular metal by siderophores is a widely accepted mode of iron acquisition, and Mtb iron-chelating siderophores, mycobactin, have been known since 1965. Currently, it is not known whether Mtb produces zinc scavenging molecules. Here, we characterize low-molecular-weight zinc-binding compounds secreted and imported by Mtb for zinc acquisition. These molecules, termed kupyaphores, are produced by a 10.8 kbp biosynthetic cluster and consists of a dipeptide core of ornithine and phenylalaninol, where amino groups are acylated with isonitrile-containing fatty acyl chains. Kupyaphores are stringently regulated and support Mtb survival under both nutritional deprivation and intoxication conditions. A kupyaphore-deficient Mtb strain is unable to mobilize sufficient zinc and shows reduced fitness upon infection. We observed early induction of kupyaphores in Mtb-infected mice lungs after infection, and these metabolites disappeared after 2 wk. Furthermore, we identify an Mtb-encoded isonitrile hydratase, which can possibly mediate intracellular zinc release through covalent modification of the isonitrile group of kupyaphores. Mtb clinical strains also produce kupyaphores during early passages. Our study thus uncovers a previously unknown zinc acquisition strategy of Mtb that could modulate host-pathogen interactions and disease outcome.

Assessing risk for severe domestic violence and related homicides perpetrated by partners and in-laws: adapted danger assessments for women in abusive relationships in India.

Despite domestic violence and related homicides perpetrated by partners and/or in-laws being a significant public health problem in India, there are no reliable and valid instruments to identify and intervene with women in domestic violence relationships. Continued domestic violence can escalate to severe, near-lethal, or lethal violence or homicide. The Danger Assessment (DA) is a risk assessment instrument designed to assess the likelihood of severe, near-lethal, or lethal violence in abusive relationships. However, the DA is not designed to determine the risk of future severe, near-lethal, or lethal violence by in-laws. In-law abuse plays a significant role in domestic violence-related homicides in India and other countries with similar cultural norms. This study addressed this gap by developing the Danger Assessment for in-laws (DA-L) to assess risk from in-laws, alongside the Danger Assessment for Women in India (DA-WI) to assess risk from partners. The study also examined the psychometric properties of the DA-L and DA-WI. Longitudinal data from 150 women in India were used to measure the reliability and validity of the two versions of the DA. The original DA items and additional risk items were examined using relative risk ratios for their relationship with severe violence at three-month follow-ups. Predictive validity was tested with the receiver operating characteristic curve. The study resulted in reliable and valid measures (11 items DA-L and 26-items DA-WI) of risk. The versions of the DA can be useful for practitioners in India and those working with Indian women in the US and other countries. The DAs can be used for identifying women in domestic violence relationships who are at risk for future severe domestic violence and guide the provision of tailored safety plans.

Metal-Organic Frameworks Derived Electrocatalysts for Oxygen and Carbon Dioxide Reduction Reaction.

The increasing demands of energy and environmental concerns have motivated researchers to cultivate renewable energy resources for replacing conventional fossil fuels. The modern energy conversion and storage devices required high efficient and stable electrocatalysts to fulfil the market demands. In previous years, we are witness for considerable developments of scientific attention in Metal-organic Frameworks (MOFs) and their derived nanomaterials in electrocatalysis. In current review article, we have discussed the progress of optimistic strategies and approaches for the manufacturing of MOF-derived functional materials and their presentation as electrocatalysts for significant energy related reactions. MOFs functioning as a self-sacrificing template bid different benefits for the preparation of metal nanostructures, metal oxides and carbon-abundant materials promoting through the porous structure, organic functionalities, abundance of metal sites and large surface area. Thorough study for the recent advancement in the MOF-derived materials, metal-coordinated N-doped carbons with single-atom active sites are emerging candidates for future commercial applications. However, there are some tasks that should be addressed, to attain improved, appreciative and controlled structural parameters for catalytic and chemical behavior.

Recent Advances in Synthesis and Applications of Single-Atom Catalysts for Rechargeable Batteries.

The rapid development of flexible and wearable optoelectronic devices, demanding the superior, reliable, and ultra-long cycling energy storage systems. But poor performances of electrode materials used in energy devices are main obstacles. Recently, single-atom catalysts (SACs) are considered as emerging and potential candidates as electrode materials for battery devices. Herein, we have discussed the recent methods for the fabrication of SACs for rechargeable metal-air batteries, metal-CO2 batteries, metal-sulfur batteries, and other batteries, following the recent advances in assembling and performance of these batteries by using SACs as electrode materials. The role of SACs to solve the bottle-neck problems of these energy storage devices and future perspectives are also discussed.

Oxidative stress specifically inhibits replication of dengue virus.

Reactive oxygen species (ROS) are chemically active species which are involved in maintaining cellular and signalling processes at physiological concentrations. Therefore, cellular components that regulate redox balance are likely to play a crucial role in viral life-cycle either as promoters of viral replication or with antiviral functions. Zinc is an essential micronutrient associated with anti-oxidative systems and helps in maintaining a balanced cellular redox state. Here, we show that zinc chelation leads to induction of reactive oxygen species (ROS) in epithelial cells and addition of zinc restores ROS levels to basal state. Addition of ROS (H2O2) inhibited dengue virus (DENV) infection in a dose-dependent manner indicating that oxidative stress has adverse effects on DENV infection. ROS affects early stages of DENV replication as observed by quantitation of positive and negative strand viral RNA. We observed that addition of ROS specifically affected viral titres of positive strand RNA viruses. We further demonstrate that ROS specifically altered SEC31A expression at the ER suggesting a role for SEC31A-mediated pathways in the life-cycle of positive strand RNA viruses and provides an opportunity to identify drug targets regulating oxidative stress responses for antiviral development.

Chandipura Virus Utilizes the Prosurvival Function of RelA NF-κB for Its Propagation.

Chandipura virus (CHPV), a cytoplasmic RNA virus, has been implicated in several outbreaks of acute encephalitis in India. Despite the relevance of CHPV to human health, how the virus interacts with the host signaling machinery remains obscure. In response to viral infections, mammalian cells activate RelA/NF-κB heterodimers, which induce genes encoding interferon beta (IFN-ß) and other immune mediators. Therefore, RelA is generally considered to be an antiviral transcription factor. However, RelA activates a wide spectrum of genes in physiological settings, and there is a paucity of direct genetic evidence substantiating antiviral RelA functions. Using mouse embryonic fibroblasts, we genetically dissected the role of RelA in CHPV pathogenesis. We found that CHPV indeed activated RelA and that RelA deficiency abrogated the expression of IFN-ß in response to virus infections. Unexpectedly, infection of Rela-/- fibroblasts led to a decreased CHPV yield. Our investigation clarified that RelA-dependent synthesis of prosurvival factors restrained infection-inflicted cell death and that exacerbated cell death processes prevented multiplication of CHPV in RelA-deficient cells. Chikungunya virus, a cytopathic RNA virus associated also with epidemics, required RelA, and Japanese encephalitis virus, which produced relatively minor cytopathic effects in fibroblasts, circumvented the need of RelA for their propagation. In sum, we documented a proviral function of the pleiotropic factor RelA linked to its prosurvival properties. RelA promoted the growth of cytopathic RNA viruses by extending the life span of infected cells, which serve as the replicative niche of intracellular pathogens. We argue that our finding bears significance for understanding host-virus interactions and may have implications for antiviral therapeutic regimes.IMPORTANCE RelA/NF-κB participates in a wide spectrum of physiological processes, including shaping immune responses against invading pathogens. In virus-infected cells, RelA typically induces the expression of IFN-ß, which restrains viral propagation in neighboring cells involving paracrine mechanisms. Our study suggested that RelA might also play a proviral role. A cell-autonomous RelA activity amplified the yield of Chandipura virus, a cytopathic RNA virus associated with human epidemics, by extending the life span of infected cells. Our finding necessitates a substantial revision of our understanding of host-virus interactions and indicates a dual role of NF-κB signaling during the course of RNA virus infections. Our study also bears significance for therapeutic regimes which alter NF-κB activities while alleviating the viral load.

Assessment of a mass media campaign on giving way to ambulances in five cities of Pakistan.

OBJECTIVE: To determine the contribution of a mass media campaign towards encouraging more vehicles to give way to ambulances, and to identify the factors associated with higher likelihood of giving way to ambulances. METHODS: The three-phase observational study was conducted from December 2017 to March 2018 in Karachi, Lahore, Rawalpindi, Islamabad and Peshawar cities of Pakistan. Six road sites in different areas of each city were selected for observation. The surveys in each city were supervised by academic partners, including APPNA Institute of Public Health, Karachi, University of Health Sciences, Lahore, Al-Nafees Medical College, Rawalpindi and Islamabad, and Khyber Medical University, Peshawar. Three observation surveys were carried out before, during and after the media campaign on right of way for ambulances. Only those ambulances were observed which were rushing through and seeking space. The behaviour of only those vehicles was observed which had the space to change the lane when the space was sought from them. The association of the outcome of vehicles giving way to ambulances immediately or in a few seconds with the campaign was determined using logistic regression analysis. RESULTS: After adjustment for city of observation, timing of the day and type of vehicle, vehicles during and after the campaign were significantly more likely give space to ambulance (p<0.05) compared to cars, buses and vans were significantly less likely to give space (p<0.05). CONCLUSIONS: Media campaign produced better results in encouraging vehicle-owners to give right of way to ambulances to ensure timely medical assistance.

The glycosylated Rv1860 protein of Mycobacterium tuberculosis inhibits dendritic cell mediated TH1 and TH17 polarization of T cells and abrogates protective immunity conferred by BCG.

We previously reported interferon gamma secretion by human CD4⁺ and CD8⁺ T cells in response to recombinant E. coli-expressed Rv1860 protein of Mycobacterium tuberculosis (MTB) as well as protection of guinea pigs against a challenge with virulent MTB following prime-boost immunization with DNA vaccine and poxvirus expressing Rv1860. In contrast, a Statens Serum Institute Mycobacterium bovis BCG (BCG-SSI) recombinant expressing MTB Rv1860 (BCG-TB1860) showed loss of protective ability compared to the parent BCG strain expressing the control GFP protein (BCG-GFP). Since Rv1860 is a secreted mannosylated protein of MTB and BCG, we investigated the effect of BCG-TB1860 on innate immunity. Relative to BCG-GFP, BCG-TB1860 effected a significant near total reduction both in secretion of cytokines IL-2, IL-12p40, IL-12p70, TNF-α, IL-6 and IL-10, and up regulation of co-stimulatory molecules MHC-II, CD40, CD54, CD80 and CD86 by infected bone marrow derived dendritic cells (BMDC), while leaving secreted levels of TGF-ß unchanged. These effects were mimicked by BCG-TB1860His which carried a 6-Histidine tag at the C-terminus of Rv1860, killed sonicated preparations of BCG-TB1860 and purified H37Rv-derived Rv1860 glycoprotein added to BCG-GFP, but not by E. coli-expressed recombinant Rv1860. Most importantly, BMDC exposed to BCG-TB1860 failed to polarize allogeneic as well as syngeneic T cells to secrete IFN-γ and IL-17 relative to BCG-GFP. Splenocytes from mice infected with BCG-SSI showed significantly less proliferation and secretion of IL-2, IFN-γ and IL-17, but secreted higher levels of IL-10 in response to in vitro restimulation with BCG-TB1860 compared to BCG-GFP. Spleens from mice infected with BCG-TB1860 also harboured significantly fewer DC expressing MHC-II, IL-12, IL-2 and TNF-α compared to mice infected with BCG-GFP. Glycoproteins of MTB, through their deleterious effects on DC may thus contribute to suppress the generation of a TH1- and TH17-dominated adaptive immune response that is vital for protection against tuberculosis.

Development of new multifunctional terpolymer sorbent for proteomics applications.

Determination of the availability of phases for specific separations is an important task achieved by a separation chemist. This becomes vital when the complex samples like biofluids are dealt with in proteome science. The work presented here involves the synthesis and application of terpolymeric sorbent with different functionalizations adopted for the selective enrichment of biomolecules of interest from biological fluids. Synthesis of terpolymer was carried out by the radical polymerization of monomers: methyl acrylate, acrylic acid and vinyl acetate with diethylene glycol dimethacrylate as cross-linking agent, benzoyl peroxide as initiator and chloroform as a porogenic solvent. Characterization was done through Fourier transform infrared spectroscopy, scanning electron microscopy and nitrogen adsorption porosimetry. The polymer was further modified to immobilized metal ion affinity chromatographic material, with immobilized Fe(3+)/La(3+) ions that allowed phosphopeptide enrichment from tryptic digests of standard proteins as well as milk, egg yolk and human serum. Sensitivity of enrichment down to 50 fmol was achieved in the presence of complex protein background as bovine serum albumin. Hydrophobicity was introduced through octadecyl amine, which provides comparable results to ZipTip C18/C4 for desalting of complex mixtures of all caseins. Analysis of the enriched content was performed by Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS).

Remediation of organic pollutant from the aqueous environment using in-house fabricated polyaniline-based hybrid composite (PANI-MnPBA/NiCoMnS) materials.

Polyaniline-based hybrid material (PANI-MnPBA/NiCoMnS) was prepared by hydrothermal-solvothermal approach. Synthesized hybrid material was characterized through FTIR-spectroscopy, p-XRD, SEM, EDX, BET, and Zetasizer techniques. Hybrid material as adsorbent for removal of Congo red (CR) from water system showed excellent results such as 98 % removal efficiency and 254 mg/g adsorption capacity. Furthermore, various studies like adsorption isothermal, kinetic, thermodynamic, and statistical analysis were performed to understand the adsorption phenomenon. From various kinetic models, pseudo-first and second-order kinetic models, intra-particle and liquid film diffusion kinetic models, pseudo-first-order kinetic model, and liquid-film diffusion kinetic model both are most suitable for explaining the adsorption phenomenon due to the greater value of R2 (0.955) for CR. According to these kinetic models, physio-sorption and diffusion play a basic role in the adsorption of CR. Moreover, ΔG (-1779.508 kJ mol-1) and ΔH (61,760.889 kJ mol-1) values explained the spontaneous and exothermic nature of the adsorption process, respectively. Furthermore, for support of the adsorption mechanism via electrostatic attractions before and after the adsorption process FTIR results of as-synthesized adsorbent were measured (NH peaks before 3668.88, after 3541.41 cm-1). These results confirm electrostatic attraction for the adsorption process. Finally, the statistical model was added (n < 1), according to this model, adsorption follows a multi-anchorage approach and adsorbent contains enough sites for adsorption of CR.

Comparing the Efficacy of Topical 4% Benzoyl Peroxide Versus Topical 0.1% Adapalene for Treatment of Acne Vulgaris in Skin of Color Population: A South Asian Perspective.

Introduction Acne vulgaris is one of the most common skin problems encountered in the dermatology department. It is a chronic, inflammatory disease of the pilosebaceous unit, clinically presenting with comedones, papules, pustules, nodules, and cysts. With its particularly high prevalence in the younger population, it has significant adverse sequelae on patient's quality of life. At present, due to an enhanced understanding of the pathogenesis of acne, various therapeutic modalities are available. The current management strategies generally follow a systematic treatment escalation based on disease severity and treatment response. However meticulous choice of appropriate anti-acne medicine for the acne type is the key to the management plan. Starting with mild to moderate types of acne as per the Leeds photometric grading scale, the most useful topical agents include topical retinoids, benzoyl peroxide, and topical antibiotics while systemic therapies such as oral antibiotics or isotretinoin are generally reserved for moderate to severe acne treatment. The skin of color (SOC) population is a relatively neglected group concerning the optimum and safe management strategies in different dermatological conditions and acne is no different, where there remains a need for comparing the available topical modalities for appropriate drug selection in the treatment of mild to moderate acne in SOC population. Objective The objective of this study was to compare the efficacy of topical 4% benzoyl peroxide versus topical 0.1% adapalene in the treatment of acne vulgaris in the SOC population. Methods The participants were divided into two groups, groups A and B. A total of 64 patients of both genders, with acne vulgaris (duration > three months) were included in the study. In group A, 32 patients were administered topical 0.1% adapalene whereas, in group B, 32 patients were given topical 4% benzoyl peroxide. Both medicines were applied at night daily. Patients were called for follow-up after 12 weeks. In both groups, the final efficacy evaluation was done using the Global Acne Grading System (GAGS) score after 12 weeks of treatment period. Results In group A, the age ranged from 15 to 40 years with a mean age of 25.781±3.93 years while the duration of complaint was 5.843±1.27 months. GAGS score was 25.281±2.65 and mean BMI was 23.092±3.51 kg/m2. In group B, the mean age was 25.187± 4.06 years, the duration of complaint was 7.375±2.25 months, the GAGS score was 23.906± 2.60 while the mean BMI was 21.485±3.88 kg/m2. Efficacy in group A was noted in 25 (78.1%) patients as compared to 24 (75%) patients in group B (p =0.768). Conclusion The present study showed that the safety and efficacy of 0.1% adapalene the traditional drug 4% benzoyl peroxide in the SOC population was comparable.

Thermodynamic Insights into Variation in Thermomechanical and Physical Properties of Isotactic Polypropylene: Effect of Shear and Cooling Rates.

In order to elucidate the effect of shear and cooling process on structural, thermomechanical, and physical properties of polymer melt, excess entropy, a thermodynamic quantity is calculated from radial distribution function generated from equilibrated parts of the molecular simulation trajectories. The structural properties are calculated, which includes the density of polypropylene melt, end to end distance, radius of gyration of the polypropylene polymer chain, and monomer-monomer radial distribution function. Non-equilibrium molecular dynamics simulation was employed to investigate the role of the applied shear rate on the properties of polypropylene. Furthermore, a range of cooling rates were employed to cool the melt. Thermomechanical properties, such as Young's modulus, and physical properties, such as glass transition temperature, were determined for different cases. Results showed that slow cooling and high shear substantially improved the Young's modulus and glass transition temperature of the i-PP. Furthermore, a two-body contribution to the excess entropy was used to elucidate the structure-property relationships in the polymer melt as well as the glassy state and the dependence of shear and cooling rate on these properties. We have used the Rosenfeld excess entropy-viscosity relationship to calculate the viscous behavior of the polymer under a steady shear condition.

Recent Advances in Transition Metal Tellurides (TMTs) and Phosphides (TMPs) for Hydrogen Evolution Electrocatalysis.

The hydrogen evolution reaction (HER) is a developing and promising technology to deliver clean energy using renewable sources. Presently, electrocatalytic water (H2O) splitting is one of the low-cost, affordable, and reliable industrial-scale effective hydrogen (H2) production methods. Nevertheless, the most active platinum (Pt) metal-based catalysts for the HER are subject to high cost and substandard stability. Therefore, a highly efficient, low-cost, and stable HER electrocatalyst is urgently desired to substitute Pt-based catalysts. Due to their low cost, outstanding stability, low overpotential, strong electronic interactions, excellent conductivity, more active sites, and abundance, transition metal tellurides (TMTs) and transition metal phosphides (TMPs) have emerged as promising electrocatalysts. This brief review focuses on the progress made over the past decade in the use of TMTs and TMPs for efficient green hydrogen production. Combining experimental and theoretical results, a detailed summary of their development is described. This review article aspires to provide the state-of-the-art guidelines and strategies for the design and development of new highly performing electrocatalysts for the upcoming energy conversion and storage electrochemical technologies.

Resolution of viral load in mild COVID-19 patients is associated with both innate and adaptive immune responses.

Over 90% of the COVID-19 patients manifest mild/moderate symptoms or are asymptomatic. Although comorbidities and dysregulation of immune response have been implicated in severe COVID-19, the host factors that associate with asymptomatic or mild infections have not been characterized. We have collected serial samples from 23 hospitalized COVID-19 patients with mild symptoms and measured the kinetics of SARS-CoV-2 viral load in respiratory samples and markers of inflammation in serum samples. We monitored seroconversion during the acute phase of illness and quantitated the amount of total IgG against the receptor-binding domain of SARS-CoV-2 and estimated the virus neutralization potential of these antibodies. Viral load decreased by day 8 in all the patients but the detection of viral RNA in saliva samples did not correlate well with viral RNA detection in nasopharyngeal/oropharyngeal swab samples. 25% of the virus-positive patients had no detectable neutralizing antibodies in the serum and in other cases, the efficiency of antibodies to neutralize SARS-CoV-2 B1.1.7 strain was lower as compared to the circulating virus isolate. Decrease in viral load coincided with increase in neutralizing antibodies and interferon levels in serum. Most patients showed no increase in inflammatory cytokines such as IL-1ß or IL-6, however, elevated levels of IL-7 and other inflammatory mediators such as TNF-α and IL-8 was observed. These data suggest that most mild infections are associated with absence of inflammation coupled with an active innate immune response, T-cell activation and neutralizing antibodies.

Humoral cross-reactivity towards SARS-CoV-2 in young children with acute respiratory infection with low-pathogenicity coronaviruses.

Background: SARS-CoV-2 infection in children frequently leads to only asymptomatic and mild infections. It has been suggested that frequent infections due to low-pathogenicity coronaviruses in children, impart immunity against SARS-CoV-2 in this age group. Methods: From a prospective birth cohort study prior to the pandemic, we identified children with proven low-pathogenicity coronavirus infections. Convalescent sera from these children were tested for antibodies against respective seasonal coronaviruses (OC43, NL63, and 229E) and SARS-CoV-2 by immunofluorescence and virus microneutralization assay respectively. Results: Forty-two children with proven seasonal coronavirus infection were included. Convalescent sera from these samples demonstrated antibodies against the respective seasonal coronaviruses. Of these, 40 serum samples showed no significant neutralization of SARS-CoV-2, while 2 samples showed inconclusive results. Conclusion: These findings suggest that the antibodies generated in low-pathogenicity coronavirus infections offer no protection from SARS-CoV-2 infection in young children.

Effectiveness of ChAdOx1 nCoV-19 vaccine against SARS-CoV-2 infection during the delta (B.1.617.2) variant surge in India: a test-negative, case-control study and a mechanistic study of post-vaccination immune responses.

BACKGROUND: SARS-CoV-2 variants of concern (VOCs) have threatened COVID-19 vaccine effectiveness. We aimed to assess the effectiveness of the ChAdOx1 nCoV-19 vaccine, predominantly against the delta (B.1.617.2) variant, in addition to the cellular immune response to vaccination. METHODS: We did a test-negative, case-control study at two medical research centres in Faridabad, India. All individuals who had a positive RT-PCR test for SARS-CoV-2 infection between April 1, 2021, and May 31, 2021, were included as cases and individuals who had a negative RT-PCR test were included as controls after matching with cases on calendar week of RT-PCR test. The primary outcome was effectiveness of complete vaccination with the ChAdOx1 nCoV-19 vaccine against laboratory-confirmed SARS-CoV-2 infection. The secondary outcomes were effectiveness of a single dose against SARS-CoV-2 infection and effectiveness of a single dose and complete vaccination against moderate-to-severe disease among infected individuals. Additionally, we tested in-vitro live-virus neutralisation and T-cell immune responses to the spike protein of the wild-type SARS-CoV-2 and VOCs among healthy (anti-nucleocapsid antibody negative) recipients of the ChAdOx1 nCoV-19 vaccine. FINDINGS: Of 2379 cases of confirmed SARS-CoV-2 infection, 85 (3·6%) were fully vaccinated compared with 168 (8·5%) of 1981 controls (adjusted OR [aOR] 0·37 [95% CI 0·28-0·48]), giving a vaccine effectiveness against SARS-CoV-2 infection of 63·1% (95% CI 51·5-72·1). 157 (6·4%) of 2451 of cases and 181 (9·1%) of 1994) controls had received a single dose of the ChAdOx1 nCoV-19 vaccine (aOR 0·54 [95% CI 0·42-0·68]), thus vaccine effectiveness of a single dose against SARS-CoV-2 infection was 46·2% (95% CI 31·6-57·7). One of 84 cases with moderate-to-severe COVID-19 was fully vaccinated compared with 84 of 2295 cases with mild COVID-19 (aOR 0·19 [95% CI 0·01-0·90]), giving a vaccine effectiveness of complete vaccination against moderate-to-severe disease of 81·5% (95% CI 9·9-99·0). The effectiveness of a single dose against moderate-to-severe disease was 79·2% (95% CI 46·1-94·0); four of 87 individuals with moderate-to-severe COVID-19 had received a single dose compared with 153 of 2364 participants with mild disease (aOR 0·20 [95% CI 0·06-0·54]). Among 49 healthy, fully vaccinated individuals, neutralising antibody responses were lower against the alpha (B.1.1.7; geometric mean titre 244·7 [95% CI 151·8-394·4]), beta (B.1.351; 97·6 [61·2-155·8]), kappa (B.1.617.1; 112·8 [72·7-175·0]), and delta (88·4 [61·2-127·8]) variants than against wild-type SARS-CoV-2 (599·4 [376·9-953·2]). However, the antigen-specific CD4 and CD8 T-cell responses were conserved against both the delta variant and wild-type SARS-CoV-2. INTERPRETATION: The ChAdOx1 nCoV-19 vaccine remained effective against moderate-to-severe COVID-19, even during a surge that was dominated by the highly transmissible delta variant of SARS-CoV-2. Spike-specific T-cell responses were maintained against the delta variant. Such cellular immune protection might compensate for waning humoral immunity. FUNDING: Department of Biotechnology India, Council of Scientific and Industrial Research India, and Fondation Botnar.

A labile point in mutant amphotericin polyketide synthases.

Streptomyces nodosus produces the antifungal polyene amphotericin B. Numerous modifications of the amphotericin polyketide synthase have yielded new analogues. However, previous inactivation of the ketoreductase in module 10 resulted in biosynthesis of truncated polyketides. Here we show that modules downstream of this domain remain intact. Therefore, loss of ketoreductase-10 activity is sufficient to cause early chain termination. This modification creates a labile point in cycle 11 of the polyketide biosynthetic pathway. Non-extendable intermediates are released to accumulate as polyenyl-pyrones.

Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein Based Novel Epitopes Induce Potent Immune Responses in vivo and Inhibit Viral Replication in vitro.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) initiates infection by attachment of the surface-exposed spike glycoprotein to the host cell receptors. The spike glycoprotein (S) is a promising target for inducing immune responses and providing protection; thus the ongoing efforts for the SARS-CoV-2 vaccine and therapeutic developments are mostly spiraling around S glycoprotein. The matured functional spike glycoprotein is presented on the virion surface as trimers, which contain two subunits, such as S1 (virus attachment) and S2 (virus fusion). The S1 subunit harbors the N-terminal domain (NTD) and the receptor-binding domain (RBD). The RBD is responsible for binding to host-cellular receptor angiotensin-converting enzyme 2 (ACE2). The NTD and RBD of S1, and the S2 of S glycoprotein are the major structural moieties to design and develop spike-based vaccine candidates and therapeutics. Here, we have identified three novel epitopes (20-amino acid peptides) in the regions NTD, RBD, and S2 domains, respectively, by structural and immunoinformatic analysis. We have shown as a proof of principle in the murine model, the potential role of these novel epitopes in-inducing humoral and cellular immune responses. Further analysis has shown that RBD and S2 directed epitopes were able to efficiently inhibit the replication of SARS-CoV-2 wild-type virus in vitro suggesting their role as virus entry inhibitors. Structural analysis revealed that S2-epitope is a part of the heptad repeat 2 (HR2) domain which might have plausible inhibitory effects on virus fusion. Taken together, this study discovered novel epitopes that might have important implications in the development of potential SARS-CoV-2 spike-based vaccine and therapeutics.

Inaccurate reporting of mineral composition by commercial stone analysis laboratories: implications for infection and metabolic stones.

PURPOSE: We determined the accuracy of stone composition analysis at commercial laboratories. MATERIALS AND METHODS: A total of 25 human renal stones with infrared spectroscopy determined composition were fragmented into aliquots and studied with micro computerized tomography to ensure fragment similarity. Representative fragments of each stone were submitted to 5 commercial stone laboratories for blinded analysis. RESULTS: All laboratories agreed on the composition of 6 pure stones. Only 2 of 4 stones (50%) known to contain struvite were identified as struvite at all laboratories. Struvite was reported as a component by some laboratories for 4 stones previously determined not to contain struvite. Overall there was disagreement regarding struvite in 6 stones (24%). For 9 calcium oxalate stones all laboratories reported some mixture of calcium oxalate but the quantity of subtypes differed significantly among laboratories. In 6 apatite containing stones apatite was missed by the laboratories in 20% of samples. None of the laboratories identified atazanavir in a stone containing that antiviral drug. One laboratory reported protein in every sample while all others reported it in only 1. Nomenclature for apatite differed among laboratories with 1 reporting apatite as carbonate apatite and never hydroxyapatite, another never reporting carbonate apatite and always reporting hydroxyapatite, and a third reporting carbonate apatite as apatite with calcium carbonate. CONCLUSIONS: Commercial laboratories reliably recognize pure calculi. However, variability in the reporting of mixed calculi suggests a problem with the accuracy of stone analysis results. There is also a lack of standard nomenclature used by laboratories.

Isolation and characterisation of amphotericin B analogues and truncated polyketide intermediates produced by genetic engineering of Streptomyces nodosus.

Amphotericin B is a powerful but toxic drug used against fungal infections and leishmaniases. These diseases would be treated more effectively if non-toxic amphotericin derivatives could be produced on a large scale at low cost. Genetic manipulation of the amphotericin B producer, Streptomyces nodosus, has previously led to the detection and partial characterisation of 8-deoxyamphotericin B, 16-descarboxyl-16-methyl-amphotericin B, 15-deoxy-16-descarboxyl-16-methyl-15-oxo-amphotericin B, 7-oxo-amphotericin B and pentaene analogues. Here we report improved production and purification protocols that have allowed detailed chemical analyses of these compounds. The polyketide synthase product 8-deoxy-16-descarboxyl-16-methyl-amphoteronolide B was identified for the first time. In addition, the ketoreductase 10 domain of the polyketide synthase was specifically inactivated by targeted gene replacement. The resulting mutants produced truncated polyketide intermediates as linear polyenyl-pyrones.