Effect of Immunosuppression on the Immune Response to SARS-CoV-2 Infection and Vaccination.

Immunosuppressive treatment in patients with rheumatic diseases can maintain disease remission but also increase risk of infection. Their response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is frequently blunted. In this study we evaluated the effect of immunosuppression exposure on humoral and T cell immune responses to SARS-CoV-2 infection and vaccination in two distinct cohorts of patients; one during acute SARS-CoV-2 infection and 3 months later during convalescence, and another prior to SARS-CoV-2 vaccination, with follow up sampling 6 weeks after vaccination. Results were compared between rituximab-exposed (in previous 6 months), immunosuppression-exposed (in previous 3 months), and non-immunosuppressed groups. The immune cell phenotype was defined by flow cytometry and ELISA. Antigen specific T cell responses were estimated using a whole blood stimulation interferon-γ release assay. A focused post-vaccine assessment of rituximab-treated patients using high dimensional spectral cytometry was conducted. Acute SARS-CoV-2 infection was characterised by T cell lymphopenia, and a reduction in NK cells and naïve CD4 and CD8 cells, without any significant differences between immunosuppressed and non-immunosuppressed patient groups. Conversely, activated CD4 and CD8 cell counts increased in non-immunosuppressed patients with acute SARS-CoV-2 infection but this response was blunted in the presence of immunosuppression. In rituximab-treated patients, antigen-specific T cell responses were preserved in SARS-CoV-2 vaccination, but patients were unable to mount an appropriate humoral response.

Molluscum Contagiosum Virus Protein MC008 Targets NF-κB Activation by Inhibiting Ubiquitination of NEMO.

Molluscum contagiosum virus (MCV) is a human-adapted poxvirus that causes a common and persistent yet mild infection characterized by distinct, contagious, papular skin lesions. These lesions are notable for having little or no inflammation associated with them and can persist for long periods without an effective clearance response from the host. Like all poxviruses, MCV encodes potent immunosuppressive proteins that perturb innate immune pathways involved in virus sensing, the interferon response, and inflammation, which collectively orchestrate antiviral immunity and clearance, with several of these pathways converging at common signaling nodes. One such node is the regulator of canonical nuclear factor kappa B (NF-κB) activation, NF-κB essential modulator (NEMO). Here, we report that the MCV protein MC008 specifically inhibits NF-κB through its interaction with NEMO, disrupting its early ubiquitin-mediated activation and subsequent downstream signaling. MC008 is the third NEMO-targeting inhibitor to be described in MCV to date, with each inhibiting NEMO activation in distinct ways, highlighting strong selective pressure to evolve multiple ways of disabling this key signaling protein. IMPORTANCE Inflammation lies at the heart of most human diseases. Understanding the pathways that drive this response is the key to new anti-inflammatory therapies. Viruses evolve to target inflammation; thus, understanding how they do this reveals how inflammation is controlled and, potentially, how to disable it when it drives disease. Molluscum contagiosum virus (MCV) has specifically evolved to infect humans and displays an unprecedented ability to suppress inflammation in our tissue. We have identified a novel inhibitor of human innate signaling from MCV, MC008, which targets NEMO, a core regulator of proinflammatory signaling. Furthermore, MC008 appears to inhibit early ubiquitination, thus interrupting later events in NEMO activation, thereby validating current models of IκB kinase (IKK) complex regulation.

Previous SARS-CoV-2 Infection, Age, and Frailty Are Associated With 6-Month Vaccine-Induced Anti-Spike Antibody Titer in Nursing Home Residents.

OBJECTIVES: Older nursing home residents make up the population at greatest risk of morbidity and mortality from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. No studies have examined the determinants of long-term antibody responses post vaccination in this group. DESIGN: Longitudinal cohort study. SETTING AND PARTICIPANTS: Residents from 5 nursing homes assessed before vaccination, and 5 weeks and 6 months post vaccination, with the BNT162b2 messenger RNA SARS-CoV-2 vaccine. METHODS: Comprehensive clinical assessment was performed, including assessment for comorbidity, frailty, and SARS-CoV-2 infection history. Serum nucleocapsid and anti-spike receptor binding domain (RBD) antibodies were analyzed at all timepoints. An in vitro angiotensin-converting enzyme (ACE2) receptor-spike RBD neutralization assay assessed serum neutralization capacity. RESULTS: Of 86 participants (81.1 ± 10.8 years; 65% female), just under half (45.4%; 39 of 86) had evidence of previous SARS-CoV-2 infection. All participants demonstrated a significant antibody response to vaccination at 5 weeks and a significant decline in this response by 6 months. SARS-CoV-2 infection history was the strongest predictor of antibody titer (log-transformed) at both 5 weeks [ß: 3.00; 95% confidence interval (CI): 2.32-3.70; P < .001] and 6 months (ß: 3.59; 95% CI: 2.89-4.28; P < .001). Independent of SARS-CoV-2 infection history, both age in years (ß: -0.05; 95% CI: -0.08 to -0.02; P < .001) and frailty (ß: -0.22; 95% CI: -0.33 to -0.11; P < .001) were associated with a significantly lower antibody titer at 6 months. Anti-spike antibody titers at both 5 weeks and 6 months significantly correlated with in vitro neutralization capacity. CONCLUSIONS AND IMPLICATIONS: In older nursing home residents, SARS-CoV-2 infection history was the strongest predictor of anti-spike antibody titers at 6 months, whereas age and frailty were independently associated with lower titers at 6 months. Antibody titers significantly correlated with in vitro neutralization capacity. Although older SARS-CoV-2 naïve nursing home residents may be particularly vulnerable to breakthrough SARS-CoV-2 infection, the relationship between antibody titers, SARS-CoV-2 infection, and clinical outcomes remains to be fully elucidated in this vulnerable population.

Dynamic Assay for Profiling Anti-SARS-CoV-2 Antibodies and Their ACE2/Spike RBD Neutralization Capacity.

Serological assays have been widely employed during the coronavirus disease 2019 (COVID-19) pandemic to measure antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to track seroconversion in populations. However, currently available assays do not allow determination of neutralization capacity within the assay protocol. Furthermore, commercial serology assays have a high buy-in cost that is inaccessible for many research groups. We have replicated the serological enzyme-linked immunosorbent assay for the detection of SARS-CoV-2 antibody isotypes, developed at the Icahn School of Medicine at Mount Sinai, New York. Additionally, we have modified the protocol to include a neutralization assay with only a minor modification to this protocol. We used this assay to screen local COVID-19 patient sera (n = 91) and pre-COVID-19 control sera (n = 103), and obtained approximate parity with approved commercial anti-nucleoprotein-based assays with these sera. Furthermore, data from our neutralization assay closely aligns with that generated using a spike-based pseudovirus infection model when a subset of patient sera was analyzed.

Targeting of the cGAS-STING system by DNA viruses.

Innate sensing of viruses by cytosolic nucleic acid sensors is a key feature of anti-viral immunity against these pathogens. The DNA sensing pathway through the sensor cyclic GMP-AMP synthase (cGAS) and its downstream effector stimulator of interferon genes (STING) has emerged in recent years as a key, front-line means of driving interferons and pro-inflammatory cytokines in response to DNA virus infection in vertebrates. Unsurprisingly, many DNA viruses have evolved effective inhibitors of this signalling system which target at a wide variety of points from sensing all the way down to the activation of Interferon Regulatory Factor (IRF)-family and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-family transcription factors which drive a program of pro-inflammatory and anti-viral gene expression. Here we review DNA viruses that have been shown to inhibit this pathway and the inhibitors they have evolved to do it.

Development and application of a screening model for evaluating bioenhanced dissolution in DNAPL source zones.

In-situ bioremediation, a widely applied treatment technology for source zones contaminated with dense non-aqueous phase liquids (DNAPLs), has proven economical and reasonably efficient for long-term management of contaminated sites. Successful application of this remedial technology, however, requires an understanding of the complex interaction of transport, mass transfer, and biotransformation processes. The bioenhancement factor, which represents the ratio of DNAPL mass transfer under microbially active conditions to that which would occur under abiotic conditions, is commonly used to quantify the effectiveness of a particular bioremediation remedy. To date, little research has been directed towards the development and validation of methods to predict bioenhancement factors under conditions representative of real sites. This work extends an existing, first-order, bioenhancement factor expression to systems with zero-order and Monod kinetics, representative of many source-zone scenarios. The utility of this model for predicting the bioenhancement factor for previously published laboratory and field experiments is evaluated. This evaluation demonstrates the applicability of these simple bioenhancement factors for preliminary experimental design and analysis, and for assessment of dissolution enhancement in ganglia-contaminated source zones. For ease of application, a set of nomographs is presented that graphically depicts the dependence of bioenhancement factor on physicochemical properties. Application of these nomographs is illustrated using data from a well-documented field site. Results suggest that this approach can successfully capture field-scale, as well as column-scale, behavior. Sensitivity analyses reveal that bioenhanced dissolution will critically depend on in-situ biomass concentrations.

Dynamic pH mapping in microfluidic devices by integrating adaptive coatings based on polyaniline with colorimetric imaging techniques.

In this paper we present a microfluidic device that has integrated pH optical sensing capabilities based on polyaniline. The optical properties of polyaniline coatings change in response to the pH of the solution that is flushed inside the microchannel offering the possibility of monitoring pH in continuous flow over a wide pH range throughout the entire channel length. This work also features an innovative detection system for spatial localisation of chemical pH gradients along microfluidic channels through the use of a low cost optical device. Specifically, the use of a microfluidic channel coated with polyaniline is shown to respond colorimetrically to pH and that effect is detected by the detection system, even when pH gradients are induced within the channel. This study explores the capability of detecting this gradient by means of imaging techniques and the mapping of the camera's response to its corresponding pH after a successful calibration process. The provision of an inherently responsive channel means that changes in the pH of a sample moving through the system can be detected dynamically using digital imaging along the entire channel length in real time, without the need to add reagents to the sample. This approach is generic and can be applied to other chemically responsive coatings immobilised on microchannels.

Optical sensing system based on wireless paired emitter detector diode device and ionogels for lab-on-a-disc water quality analysis.

This work describes the first use of a wireless paired emitter detector diode device (PEDD) as an optical sensor for water quality monitoring in a lab-on-a-disc device. The microfluidic platform, based on an ionogel sensing area combined with a low-cost optical sensor, is applied for quantitative pH and qualitative turbidity monitoring of water samples at point-of-need. The autonomous capabilities of the PEDD system, combined with the portability and wireless communication of the full device, provide the flexibility needed for on-site water testing. Water samples from local fresh and brackish sources were successfully analysed using the device, showing very good correlation with standard bench-top systems.

Remote real-time monitoring of subsurface landfill gas migration.

The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months.

Experimental and numerical validation of the total trapping number for prediction of DNAPL mobilization.

The total trapping number (N(T)), quantifying the balance of gravitational, viscous, and capillaryforces acting on an entrapped dense nonaqueous phase liquid (DNAPL) droplet was originally developed as a criterion to predict the onset and extent of residual DNAPL mobilization in porous media. The ability of this approach to predict mobilization behavior, however, has not been rigorously validated in multidimensional systems. In this work, experimental observations of residual tetrachloroethene (PCE) mobilization in rectangular columns are compared to predictions obtained using a multiphase compositional finite-element simulator that was modified to incorporate the dependence of entrapped residual,flow, and transport parameters on the total trapping number. Consistent with calculated NT values (1.21 x 10(-3)-1.10 x 10(-2)), residual PCE-DNAPL was mobilized immediately upon contact with a low-interfacial tension (IFT) surfactant solution and rapidly migrated downward to form a bank of mobile DNAPL. The numerical model accurately captured the onset and extent of PCE-DNAPL mobilization, the angle and migration of the DNAPL bank, the swept path of the surfactant solution, and cumulative PCE recovery. These findings demonstrate the utility of the total trapping number for prediction of DNAPL mobilization behavior during low-IFT flushing.

Elevation of transgene expression level by flanking matrix attachment regions (MAR) is promoter dependent: a study of the interactions of six promoters with the RB7 3' MAR.

We have analyzed effects of a matrix attachment region (MAR) from the tobacco RB7 gene on transgene expression from six different promoters in stably transformed tobacco cell cultures. The presence of MARs flanking the transgene increased expression of constructs based on the constitutive CaMV 35S, NOS, and OCS promoters. Expression from an induced heat shock promoter was also increased and MARs did not cause expression in the absence of heat shock. There was also no effect of MARs on the pea ferredoxin promoter, which is not normally expressed in this cell line. Importantly, most transgenes flanked by RB7 MAR elements showed a large reduction in the number of low expressing GUS transformants relative to control constructs without MARs.