The molecular immune modulator adenosine deaminase-1 enhances HIV specific humoral and cellular responses to a native-like HIV envelope trimer DNA vaccine

There is currently no prophylactic vaccine available for human immunodeficiency virus (HIV). Research efforts have resulted in improved immunogens that mimic the native envelope (Env) glycoprotein structure. Recently, a novel triple tandem trimer (TTT) platform has been used to generate a plasmid encoding Env immunogen (pBG505-TTT) that expresses only as trimers, making it more suitable for nucleic acid vaccines. We have previously demonstrated that adenosine deaminase-1 (ADA-1) is critical to the T follicular helper (TFH) function and improves vaccine immune responses in vivo. In this study, we demonstrate that co-delivery of plasmid-encoded adenosine deaminase 1 (pADA) with pBG505-TTT enhances the magnitude, durability, isotype switching and functionality of HIV-specific antibodies in a dose-sparing manner. Co-delivery of the molecular immune modulator ADA-1 also enhances HIV-specific T cell polyfunctionality, activation, and degranulation as well as memory B cell responses. These data demonstrate that pADA enhances HIV-specific cellular and humoral immunity, making ADA-1 a promising immune modulator for HIV-targeting vaccines.

Outcomes of Percutaneous Revascularization in Severe Ischemic Left Ventricular Dysfunction

PURPOSE OF REVIEW

This article presents a comprehensive review of coronary revascularization versus optimal medical therapy (OMT) in patients with severe ischemic left ventricular dysfunction.

RECENT FINDINGS

The REVIVED-BCIS2 trial randomized 700 patients with extensive coronary artery disease and left ventricular (LV) ejection fraction (LVEF) ≤ 35% and viability in more than four dysfunctional myocardial segments to percutaneous coronary intervention (PCI) plus OMT versus OMT alone. Over a median duration of 41 months, there was no difference in the composite of all-cause mortality, heart failure hospitalization, or improvement in LVEF with PCI plus OMT versus OMT alone at 6 and 12 months, quality of life scores at 24 months, or fatal ventricular arrhythmia. The STICH randomized trial was conducted between 2002 and 2007, involving patients with LV dysfunction and coronary artery disease. The patients were assigned to either CABG plus medical therapy or medical therapy alone. At the 5-year follow-up, the trial showed that CABG plus medical therapy reduced cardiovascular disease-related deaths and hospitalizations but no reduction in all-cause mortality. However, a 10-year follow-up showed a significant decrease in all-cause mortality with CABG. The currently available evidence showed no apparent benefit of PCI in severe ischemic cardiomyopathy as compared to OMT, but that CABG improves outcomes in this patient population. The paucity of data on the advantages of PCI in this patient population underscores the critical need for optimization of medical therapy for better survival and quality of life until further evidence from RCTs is available.

Welding of thin stainless-steel sheets using a QCW green laser source

Bipolar plates are structured thin metal sheets and are, next to the membrane electrode assembly (MEA), one of the main components of polymer electrolyte membrane fuel cells. One of the production steps of such bipolar plates is the joining process of its two halves. Laser welding is a suitable method for such an application since it is fast, non-contact, automatable, and scalable. Particularly important aspects of the weld seam are the weld seam width and depth. In this paper, welding of stainless-steel material analogous to materials used in bipolar plates is examined. For this purpose, a newly developed quasi continuous wave (QCW) green laser source with higher beam quality is employed to assess the effect of the wavelength and the spot diameter on the welding of stainless-steel material. By using various focusing lens, different sized beam diameters below 20 µm are achieved and their influence on the final welding result-specifically concerning the seam width-are analyzed. With welding speeds starting at 500 mm/s, reduced weld seam widths (≤ 100 µm) are realized, particularly with a focusing lens of 200 mm focal distance. The suitability of such a process for thin channels of under 75 µm width is examined.

IgM N-glycosylation correlates with COVID-19 severity and rate of complement deposition

The glycosylation of IgG plays a critical role during human SARS-CoV-2, activating immune cells and inducing cytokine production. However, the role of IgM N-glycosylation has not been studied during acute viral infection in humans. In vitro evidence suggests that the glycosylation of IgM inhibits T cell proliferation and alters complement activation rates. The analysis of IgM N-glycosylation from healthy controls and hospitalized COVID-19 patients reveals that mannosylation and sialyation levels associate with COVID-19 severity. Specifically, we find increased di- and tri-sialylated glycans and altered mannose glycans in total serum IgM in severe COVID-19 patients when compared to moderate COVID-19 patients. This is in direct contrast with the decrease of sialic acid found on the serum IgG from the same cohorts. Moreover, the degree of mannosylation and sialylation correlated significantly with markers of disease severity: D-dimer, BUN, creatinine, potassium, and early anti-COVID-19 amounts of IgG, IgA, and IgM. Further, IL-16 and IL-18 cytokines showed similar trends with the amount of mannose and sialic acid present on IgM, implicating these cytokines' potential to impact glycosyltransferase expression during IgM production. When examining PBMC mRNA transcripts, we observe a decrease in the expression of Golgi mannosidases that correlates with the overall reduction in mannose processing we detect in the IgM N-glycosylation profile. Importantly, we found that IgM contains alpha-2,3 linked sialic acids in addition to the previously reported alpha-2,6 linkage. We also report that antigen-specific IgM antibody-dependent complement deposition is elevated in severe COVID-19 patients. Taken together, this work links the immunoglobulin M N-glycosylation with COVID-19 severity and highlights the need to understand the connection between IgM glycosylation and downstream immune function during human disease.

Mechanism of nanoplastics capture by jellyfish mucin and its potential as a sustainable water treatment technology

The accumulation of nanoplastics (NPs) in the environment has raised concerns about their impact on human health and the biosphere. The main aim of this study is to understand the mechanism that governs the capture of NPs by jellyfish mucus extracted from the jellyfish Aurelia sp. (A.a.) and compare the capture/removal efficiency to that of conventional coagulants and mucus from other organisms. The efficacy of A.a mucus to capture polystyrene and acrylic NPs (∼100 nm) from spiked wastewater treatment plant (WWTP) effluent was evaluated. The mucus effect on capture kinetics and destabilization of NPs of different polymer compositions, sizes and concentrations was quantified by means of fluorescent NPs, dynamic light scattering and zeta potential measurements and visualized by scanning electron microscopy. A dosing of A.a. mucus equivalent to protein concentrations of ∼2-4 mg L^-1 led to a rapid change in zeta potential from a baseline of -30 mV to values close to 0 mV, indicating a marked change from a stable to a non-stable dispersion leading to a rapid (<10 min) and significant removal of NPs (60 %-90 %) from a stable suspension. The A.a. mucus outperformed all other mucus types (0-37 %) and coagulants (0 %-32 % for ferric chloride; 23-40 % for poly aluminum chlorohydrate), highlighting the potential for jellyfish mucus to be used as bio-flocculant. The results indicate a mucus-particle interaction consisting of adsorption-bridging and "mesh" filtration. Further insight is provided by carbohydrate composition and protein disruption analysis. Total protein disruption resulted in a complete loss of the A.a. mucus capacity to capture NPs, while the breaking of disulfide bonds and protein unfolding resulted in improved capture capacity. The study demonstrates that natural jellyfish mucin can capture and remove NPs in water and wastewater treatment systems more efficiently than conventional coagulants, highlighting the potential for development of a new type of bio-flocculant.

Lipid nanoparticles (LNP) induce activation and maturation of antigen presenting cells in young and aged individuals

Despite the overwhelming success of mRNA-based vaccine in protecting against SARS-CoV-2 infection and reducing disease severity and hospitalization, little is known about the role lipid nanoparticles (LNP) play in initiating immune response. In this report we studied the adjuvantive impact of empty LNP with no mRNA cargo (eLNP) on anti-viral pathways and immune function of cells from young and aged individuals. We found that eLNP induced maturation of monocyte derived dendritic cells by measuring the expression of CD40, CD80, HLA-DR and production of cytokines including IFN-α,IL-6, IFN-γ, IL-12, and IL-21. Flow cytometry analysis of specific dendritic cell subsets showed that eLNP can induce CD40 expression and cytokine production in cDC1, cDC2 and monocytes. Empty LNP (eLNP) effects on dendritic cells and monocytes coincided with induction pIRF7 and pTBK1, which are both important in mitigating innate immune signaling. Interestingly our data show that in response to eLNP stimulus at 6 and 24 hrs, aged individuals have decreased CD40 expression and reduced IFN- γ output compared to young adults. Furthermore, we show that cDC1, cDC2, and CD14 ^dim CD16 ⁺ monocytes from healthy aged individuals have dysregulated anti-viral signaling response to eLNP stimulation as measured by the defect in type I IFN production, phosphorylation of IRF7, TBK-1, and immune function like phagocytosis. These data showed a novel function of eLNP in eliciting DC maturation and innate immune signaling pathways and that some of these functions are impaired in older individuals providing some suggestion of why older individuals (> 65 yrs of age) respond display lower immune responses and adverse events to SARS-CoV-2 mRNA-based vaccines.

Advances in Percutaneous Management of Pulmonary Embolism

Acute pulmonary embolism (PE) is a leading cause of morbidity and mortality worldwide. Systemic anticoagulation remains the recommended treatment for low-risk PE. Systemic thrombolysis is the recommended treatment for PE with hemodynamic compromise (massive/high-risk PE). A significant number of patients are not candidates for systemic thrombolysis due to the bleeding risk associated with thrombolytics. Historically, surgical pulmonary embolectomy (SPE) was recommended for massive PE with hemodynamic compromise for these patients. In the last decade, catheter-directed thrombolysis (CDT) has largely replaced SPE in the patient population with intermediate risk PE (submassive), defined as right heart strain (as evidenced by right ventricle enlargement on echocardiogram and/or computed tomography, usually along with elevation of troponin or B-type natriuretic peptide). Use of CDT increased in the last few years due to high incidence of PE in hospitalized patients with coronavirus disease 2019 pneumonia, and the use of mechanical thrombectomy (initially reserved for those with contraindications to thrombolysis) has also grown. In this article, we discuss the value of the PE response team, our approach to management of submassive (intermediate risk) and massive (high risk) PE with systemic thrombolytics, CDT, mechanical thrombectomy, and surgical embolectomy.

Antegrade dissection and re-entry versus parallel wiring in chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry

BACKGROUND

The comparative efficacy and safety of parallel wiring versus antegrade dissection and re-entry (ADR) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is controversial.

METHODS

We compared the clinical and angiographic characteristics and outcomes of parallel wiring versus ADR after failed antegrade wiring in a large, multicenter CTO PCI registry.

RESULTS

A total of 1725 CTO PCI procedures with failed antegrade wiring with a single wire were approached with parallel wiring (692) or ADR (1033) at the discretion of the operator. ADR patients were older (65 ± 10 vs. 62 ± 10, years, p < 0.001) and had higher prevalence of comorbidities, such as diabetes mellitus (43% vs. 32%, p < 0.001), prior coronary artery bypass graft surgery (31% vs. 19%, p < 0.001), and lower left ventricular ejection fraction (50 ± 14 vs. 53 ± 11%, p < 0.001). The ADR group had higher J-CTO (2.8 ± 1.1 vs. 2.1 ± 1.3, p < 0.001) and PROGRESS-CTO (1.6 ± 1.1 vs. 1.2 ± 1.0, p < 0.001) scores. Equipment use including guidewires, balloons, and microcatheters was higher, and the procedures lasted longer in the ADR group. Technical success (78% vs. 75%, p = 0.046) and major adverse cardiovascular events (composite of all-cause mortality, stroke, acute myocardial infarction, emergency surgery or re-PCI, and pericardiocentesis) (3.7% vs. 1.9%, p = 0.029) were higher in the ADR group, with similar procedural success (75% vs. 73%, p = 0.166).

CONCLUSION

In lesions that could not be crossed with antegrade wiring, ADR was associated with higher technical but not procedural success, and also higher MACE compared with parallel wiring.

Anti‐S2 Protection in COVID‐19 Infection and SARS‐CoV‐2 Spike Vaccination

The overall goal of this project is to define the magnitude, quality, and duration of the primary immune response elicited against SARS‐CoV‐2 Spike by measuring domain‐specific antibody abundance and binding characteristics in plasmas after infection and vaccination. This investigation has enabled initiation of the screening of convalescent plasma polyclonal antibody (pAb) abundance and specificity through the IMPACC (Immunophenotyping Assessment in a COVID‐19 Cohort) at Drexel U College of Medicine (DUCOM) in collaboration with Tower Health Hospitals. We measured the active concentration of pAbs specific for RBD, S1 and S2 domains using SPR (surface plasmon resonance) molecular interaction analysis. By adopting a kinetic format, a complementary SPR analysis step was optimized to determine the binding rates and affinities of elicited antibodies targeting each domain of the Spike using the same plasma dilution aliquot. Most importantly, we found that the abundance of S2 reactive antibodies was comparable to that of anti‐S1 and RBD in convalescent plasmas. Plasmas obtained up to 6 months post‐vaccination are also becoming available through the TTC (Vaccination TetraCore cohort) assessment at DUCOM, and screening for these has demonstrated that anti‐S2 pAbs are also elicited, though intriguingly in lower abundance than after infection. To assess the importance anti‐S2 antibodies from convalescent plasmas, we purified anti‐S2 fractions by an SPR‐based microaffinity method and used the recovered antibodies in pseudovirus infection inhibition assays of ACE2 expressing cells to measure neutralization activity. Evidence for sustained generation of S2 antibodies up to 6 months post‐infection and occurrence of neutralizing anti‐S2 pAbs has begun to emerge with the possibility that antibodies targeting the S2 domain of the SARS‐CoV‐2 spike protein complex could provide pan‐coronavirus protection against COVID‐19, emerging variants, and other coronaviruses with conserved spike structures. Targeting the more conserved fusion machinery in the virus spike ultimately can lead to therapeutic antibodies or small molecule inhibitors effective on escape variants that occur mainly in S1 as well as other coronaviruses.

Adenosine deaminase-1 (ADA-1) induces maturation and skewing of cytokine and chemokine production in dendritic cells to improve adaptive immune responses

Dendritic cells (DCs) are critical mediators of antigen-specific immunity through their ability to present antigen and drive T cell differentiation into different effector subsets such as follicular helper T cells (TFH). TFH cells provide both physical and cytokine-mediated stimuli to B cells resulting in somatic hypermutation and class-switching of B cell receptors. Molecules that target TFH cells, such as adenosine deaminase-1 (ADA-1), would improve humoral immunity. We have previously demonstrated that co-delivery of plasmid-encoded adenosine deaminase with an HIV-1 envelope and SARS-CoV-2 DNA vaccines in vivo, enhanced both humoral and cellular responses. However, the mechanism by which ADA-1 is acting as an adjuvant remains to be elucidated. To this end, we treated monocyte-derived DCs from healthy human donors in vitro with recombinant ADA-1 protein and evaluated the expression of maturation markers, cytokines and chemokines. ADA-1-treated DCs had a significantly increased expression of CD40 and CD86 as well as HLA-DR compared to their unstimulated, immature counterparts. The level of co-stimulatory marker and HLA-DR expression on ADA-1-treated DCs was similar to that on LPS/IFN-γ-treated DCs, indicating ADA-1-mediated DC maturation. ADA-1-treated DCs also exhibited a significant increase in IL-6, IL-1β and CXCL13 expression. IL-6 is a key pro-TFH cytokine and IL-1β and CXCL13 may play a role in TFH cell differentiation, function, and proliferation. Ongoing studies are aimed to drive ADA-1 overexpression in DCs and evaluate effects on antigen presentation. Overall, elucidating the mechanism of ADA-1’s adjuvanticity will allow for its progression as a clinical adjuvant.

This work was supported by funding to Dr. Elias Haddad from NIH 5RO1AI106482-01A and 1U19 AI128910-01.

Role of exosomal BTLA/HVEM signaling in HTLV-1 associated diseases and associated T-cell dysfunction

Immune checkpoint (ICP) mediators play pivotal roles in regulating a broad spectrum of immune responses against cancer and infectious diseases. In previous studies we have established the role of negative checkpoint receptors (NCRs, PD-1, TIGIT, LAG-3, etc.) in determining the quality of anti-HTLV-1 cytolytic (CTL) response in controlling proviral load and maintaining a asymptomatic state in majority of infected individuals. Interestingly, ICPs can be released in the soluble form and carried on the surface of small extracellular vesicles (50–200 nm) known as exosomes that possess immunomodulatory activity. Consequently, we profiled ICPs in isolated exosomes and culture media of HTLV-1 cell lines representing both HAM/TSP and ATLL. High levels of BTLA (B-and T-Lymphocyte Attenuator) and its ligand HVEM (Herpes virus entry mediator) along with PD-1 (Programmed cell death receptor-1) and its ligand PD-L2 (not PD-L1) were observed in soluble and exosomal forms as well in the sera of HAM patients that carry high proviral load and viral proteins such as Tax. HTLV-1 infection, Tax protein and/or IFNy could serve as causative mechanism for increased ICP levels in HAM patients. Indeed, treatment with anti-retroviral drugs significantly reduced ICP levels confirming specificity of our observations. Functionality of exosomal BTLA/HVEM is being validated in the ongoing studies along with their direct role in regulating CD8 T-cell functions and cytolytic potential upon blockade to provide a novel therapeutic target for HAM/TSP and other neuroinflammatory diseases.

Supported by grants from NIH: 1R01NS0971-47, T32-MH079785

Anxiety and sleep quality in a sample of Lebanese healthcare workers during the COVID-19 outbreak

A cross-sectional, survey based study was conducted in order to assess mental health outcomes among healthcare workers in a private university hospital involved in the COVID-19 response in Lebanon. The main objective was to quantify symptoms of anxiety and sleep quality using self-rating scales (the State-Trait Anxiety Inventory (STAI) and Pittsburgh Sleep Quality Index (PSQI) respectively), while identifying factors that might affect those symptoms. A total of 628 healthcare workers completed the survey; 409 (66.2%) were younger than 40 years, and 441 (71.4%) were women. Of all participants, 503 (81.4%) were nurses, 52 (8.4%) were physicians and 63 (10.2%) were residents. Registered nurses, residents, women, and younger participants presented higher scores on both scales than other categories of participants. Among factors related with COVID-19, those associated with higher scores were having relatives affected by the virus (22.2%), being excessively exposed to media (12.9%), and increasing the consumption of substances/alcohol (31.2%) during this period. Factors associated with higher risk of anxiety symptoms after multivariable logistic regression analysis were: female sex, young age, poor sleep quality, and living with elderly. Our findings contribute to the understanding of the psychological wellbeing of health care workers involved in the acute COVID-19 outbreak in Lebanon.

Co-immunization with adenosine deaminase rescues age-associated impairment of SARS-COV-2 synDNA vaccine-induced responses

SARS-CoV-2 is responsible for a global pandemic claiming over 2 million lives and infecting over 100 million people. Elderly patients display increased COVID-19 morbidity and mortality. Vaccine candidates have been studied and deployed in the clinic. However, age-associated immune deficits are known to cause sub-optimal responses, and the longevity of vaccine-induced responses is under investigation. Germinal center follicular helper T cells (TFH) promote affinity maturation of B cell receptors and memory B cell differentiation and are defined by expression of adenosine deaminase-1 (ADA-1). We investigated the adjuvant properties of plasmid-encoded adenosine deaminase (pADA) in the context of a SARS-CoV-2 spike synDNA antigens. Young and aged mice were immunized with plasmid-encoded spike (pS) alone or co-immunized with pS and pADA and cellular and humoral responses were evaluated. When immunized with pS alone, aged mice had decreased spike-binding IgG and neutralization titers. However, young and aged animals co-immunized with pADA had similar humoral responses. We observed similar trends in serum antibody affinity as measured by SPR. pADA co-immunization also rescued age-associated decreases in spike-specific IFNy secretion in the spleens and lungs of co-immunized aged mice as measured by ELISpot. Finally, preliminary data analysis indicates that co-immunization with pADA significantly impacts viral load in a model of SARS-CoV-2 infection. These data suggest that pADA enhances antigen-specific cellular and humoral immunity in aged mice and supports further study of this molecule as an immunoadjuvant for vaccines targeting elderly populations.

The Impact of Aging on Antiviral Pathways and Consequences for Immune Function

It is known that aging leads to increased morbidity and mortality, however, this has become more of a concern as the world population shifts to an increased percentage of older adults (&gt;65) especially for COVID-19. These deaths may be from immunosenescence, a condition of chronic increased level of basal inflammation which can also result in diminished vaccine responses and immune system dysregulation, leading to COVID-19 complications. Current research shows a decrease in pro-inflammatory cytokines but the downstream signaling pathways in the context of aging have yet to be evaluated. Two critical pathway points in the production of type I IFN are the phosphorylation of pIRF7 in the TLR 7/8 pathway and of pTBK-1 in the RIG-I and cGAS-STING pathways. We show a decrease in pIRF7 and pTBK-1 in cDC1s, cDC2s, and CD14dimCD16+vascular patrolling monocytes from older adults (n=12) following stimulation with pathway specific agonists in comparison with healthy controls (n=12). This decrease correlates with decreased phagocytosis in the same cell subsets. These data support our previous reports of a delayed and decreased pro-inflammatory output following stimulation and demonstrate potential targets of antiviral pathways that can resolve dysfunctions of the aging immune system for an effective vaccination response. Therefore, we further hypothesize that cDC1, cDC2, and CD14dimCD16+ from older adults will have reduced antigen presentation and ability to cross-present viral peptides. We will utilize COVID-19 patient samples (n=110) to assess antigen-specificity of DCs and T cells in older COVID-19 pos. patients vs healthy controls (n=12).

A63 REFINING THE CANADIAN ASSOCIATION OF GASTROENTEROLOGY GUIDELINE ON SCREENING IN PERSONS WITH A FAMILY HISTORY OF NONHEREDITARY COLORECTAL CANCER OR ADENOMA: A MODIFIED DELPHI PROCESS

Background

In 2018, the Canadian Association of Gastroenterology (CAG) published an extensive systematic review and guideline on screening in persons with a family history (FHx) of nonhereditary colorectal cancer (CRC) and adenoma. While CAG’s recommendations were evidence-based, some recommendations lacked precision (e.g. ranges for some start ages & intervals) and screening cessation age was not addressed, leading to implementation challenges for practitioners and CRC screening programs.

Aims

To review and update the evidence since the 2018 guideline and to formulate implementable recommendations in the Ontario context that are aligned with the CAG guideline.

Methods

ColonCancerCheck (Ontario’s organized CRC screening program) conducted a modified version of the literature search used by CAG (Jan 2017 - Sept 2019). A 19-member expert panel with Canadian and international representatives from endoscopy, primary care, epidemiology, organized CRC screening programs, Ontario’s cancer system and the general public refined the recommendations of the CAG guideline for the purposes of implementation in an organized CRC screening program using a modified Delphi process. This iterative process involved a series of webinars and anonymous survey rounds where the panel reviewed evidence materials and provided online feedback to develop, refine & achieve consensus on screening recommendations in persons with a FHx of CRC/adenoma. Consensus was achieved if ≥75% of members agreed or strongly agreed with the statement.

Results

Six new systematic reviews and 2 new guidelines were identified. New evidence included data on the absolute risk (10 year & lifetime risk) of CRC by type of FHx, as well as the performance of fecal immunochemical testing (FIT) and barriers to CRC screening in persons with a FHx of CRC. The expert panel participated in 3 webinars and 4 online surveys to arrive at consensus. Panel recommendations and level of consensus will be reported for the 6 statements (Table).

Conclusions

Building from the CAG guideline, we derived evidence-based and implementable recommendations for screening persons with a FHx of CRC or adenoma.

Funding Agencies

Ontario Health (Cancer Care Ontario)

Microplastic distributions in a domestic wastewater treatment plant: Removal efficiency, seasonal variation and influence of sampling technique

Wastewater treatment plants (WWTPs) serve as an important route of microplastics (MPs) to the environment. Therefore, more effective MPs sampling and detection methodologies, as well as a better understanding of their influence on MPs occurrence and distributions in WWTP effluents, are needed for better removal and control. In this work, the efficiency of a municipal WWTP to remove MPs was assessed by collecting samples from raw to tertiary effluent during a 12-month sampling campaign (season-based) using different sampling methods (containers, 24-h composite and large grab samples). MPs retrieved from different treatment units within the WWTP were identified and quantified using plastic/non-plastic staining followed by optical microscopy, SEM and μ-Raman microscopy. Overall, the mean removal efficiency of MPs in the WWTP was 97%, with most MPs removed by the secondary stage and a mean effluent concentration of 1.97 MPs L^-1 after sand filtration. The relative abundance of particles was lower than fibers in treated effluent compared with the raw wastewater, with MP fibers constituting 74% of the total MPs in raw wastewater and 91% in treated effluent. Taking seasonal variations into account is important as total MPs concentration in the effluent was notably higher in winter compared with the other seasons. Increasing the sampled volume using large samples or 24-h composite samples significantly reduced the variability between replicates. However, MPs concentration post the tertiary stage was significantly lower using morning sampling (9 am) by large grab sampling method (1.2 MPs L^-1) compared to 24-h composite sampling (3.2 MPs L^-1) possibly due to intra-daily changes. Using a finer mesh size (0.45 μm) to capture MPs beyond the size range typically studied (≥20 μm) effectively doubled the number of MPs detected in the tertiary effluent and highlights the importance of standardizing sampling procedures.

Are two consecutive negative RT-PCR results enough to rule out COVID-19?

The coronavirus disease 2019 (COVID-19) pandemic is redefining the world we live in, and scientists are struggling to find the best severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic tool. Routine testing is currently performed using real-time reverse transcription PCR (RT-PCR) of upper or lower respiratory tract secretions. We sought to demonstrate the importance of conducting RT-PCR using deep sampling when initial upper respiratory testing is negative in cases of high index of suspicion for COVID-19. We present the case of a 47-year-old man admitted for fever and bilateral pneumonia diagnosed via chest computed tomographic scan amidst the early peak of the COVID-19 pandemic, suggesting a SARS-CoV-2 infection. Two RT-PCR results from nasopharyngeal swab samples were negative. A bronchoscopy was then performed, and RT-PCR testing on bronchoalveolar lavage samples yielded positive results, confirming the diagnosis of COVID-19 pneumonia. RT-PCR samples of the lower respiratory tract likely contain a higher virus load and thus retain a higher sensitivity for SARS-CoV-2 detection.

CCR10 expression is required for the adjuvant activity of the mucosal chemokine CCL28 when delivered in the context of an HIV-1 Env DNA vaccine

An effective prophylactic vaccine targeting HIV must induce a robust humoral response and must direct the bulk of this response to the mucosa-the primary site of HIV transmission. The chemokine, CCL28, is secreted by epithelial cells at mucosal surfaces and recruits' cells expressing its receptor CCR10. CCR10 is predominantly expressed by IgA + ASCs. We hypothesized that co-immunization with plasmid DNA encoding consensus envelope antigens with plasmid-encoded CCL28 would enhance anti-HIV IgA responses at mucosal surfaces. Indeed, animals receiving pCCL28 and pEnvA/C had significantly increased HIV-specific IgA in fecal extract. Surprisingly, CCL28 co-immunization induced a significant increase in anti-HIV IgG in the serum in mice compared to those receiving pEnvA/C alone. These robust antibody responses were not associated with changes in the frequency of germinal center B cells but depended upon the expression of CCR10, as these responses we abolished in CCR10-deficient animals. Finally, immunization with CCL28 led to increased frequencies in HIV-specific CCR10 + and CCR10 + IgA + B cells in the small intestine and Peyer's patches of vaccinated animals as compared to those receiving pEnvA/C alone. These data indicate that CCL28 administration can enhance antigen-specific humoral responses systemically and at mucosal surfaces.

Intravesical Bacillus Calmette-Guérin (BCG) treatment's severe complications: A single institution review of incidence, presentation and treatment outcome

Objectives

Intravesical Bacillus Calmette-Guérin (BCG) treatment for superficial bladder cancer is interrupted in approximatively 8% of cases as a result of complications. The objective is to report the severe related complications of Bacillus Calmette-Guérin (BCG) following an intravesical instillation for bladder tumor encountered at our institution for the past 5 years.

Methods

Medical records of a tertiary teaching hospital, located in Beirut, Lebanon, were retrospectively analyzed from June 2014 to June 2019 searching for severe related complications of BCG. A comprehensive review of articles on this subject was conducted.

Results

The incidence of severe systemic adverse events related to BCG instillation was 1.5% (5 out of 332 patients). A total of five patients were found to have a severe BCG related complication, with fever, chills, and irritative urinary signs being the most frequent symptoms. All patients received antituberculosis therapy (Isoniazid, Rifampin and Ethambutol). Two were put on add-on corticosteroids. Three patients had a computed tomography scan image in favor of an infection. Two patients had a favorable outcome, three patients died.

Conclusion

BCG severe adverse events were mostly seen in patients with a traumatic instillation. Treatment used at our institution was similar to most cases reported in the literature. A standardized diagnostic and treatment approach should be implemented to help physicians tackle these life-threatening complications.

A106 TTC7A MUTATION AND CHRONIC PRURITUS, A CASE REPORT

Background

TTC7A mutation is a rare autosomal recessive disease that can present with various phenotypes including multiple intestinal atresia (MIA), very early onset inflammatory bowel disease (VEOIBD), and profound combined immunodeficiency with hypoplastic thymus, altered T- and B-cell maturation, lymphopenia, monocytosis and agammaglobulinemia. Although TTC7A mutation mostly affects immune and gut function, it is a multisystemic disease. Chronic pruritus has not been described yet.

Aims

To describe the case of a child with TTC7A mutation with chronic pruritus and the potential treatment options.

Methods

Case report and review of literature

Results

We report a child with TTC7A mutation who developed severe chronic pruritus. The child presented ileal atresia and pyloric stenosis and underwent ileo-caecal resection and pyloroplasty at birth. She required a latero-lateral anastomosis between the stomach and the duodenum because of recurring pyloric stenosis and several dilatations of her ileo-colic anastomosis. She remained dependant on parenteral nutrition for most of her caloric needs. Her immune deficiency manifested with a very low lymphocyte count and low immunoglobulins. She had pneumocystis Carinii infection at 3 months of age and was put on gammaglobulin injections and pentamidine prophylaxis. At 3 years of age, she developed severe pruritus that led to skin infection and recurrent Staphylococcus Aureus sepsis. A skin biopsy revealed eczematous dermatitis with eosinophilic infiltration.

Various treatments were attempted. Replacing lipid fat emulsion by fish oil emulsion in her parenteral nutrition did not improve her symptoms. Amitryptiline, gabapentine, hydroxyzine hydrochloride and levofloxacine also failed. Corticosteroids seemed to have a mild effect. A trial of Mepolizumab (anti-IL 5) was unsuccessful.

At age of 4, after a sepsis treated by vancomycin, she presented with severe bullous skin disease. Skin biopsy was compatible with linear IgA bullous dermatosis. She was put on dupilumab and systemic corticosteroids. Dupilumab inhibits signaling of both IL-4 and IL-13, two cytokines involved in inflammation that contribute to atopic dermatitis. With this combination of IV steroids and dupilumab, pruritus has improved significantly.

Conclusions

Our patient’s evolution suggests that some TTC7A mutation can be complicated with severe pruritus and IgA linear bullosis. Skin disease, combined with immunodeficiency and the presence of a central line can lead to life threatening sepsis. Pruritus did not respond to usual treatments but improved the combination of intravenous steroids and dupilumab suggesting a role of IL-4 and IL-13 in the pathophysiology of the pruritus associated with this disease. Hematopoietic stem cell transplantation, may be an alternative solution.

Funding Agencies

None

Phase-matching-free pulse retrieval based on transient absorption in solids

In this paper, we introduce a pulse characterization technique that is free of phase-matching constraints, exploiting transient absorption in solids as an ultrafast optical switch. Based on a pump-probe setup, this technique uses pump pulses of sufficient intensity to induce the switch, while the pulses to characterize are probing the transmissivity drop of the photoexcited material. This enables the characterization of low-intensity ultra-broadband pulses at the detection limit of the spectrometer and within the transparency range of the solid. For example, by using zinc selenide (ZnSe), pulses with wavelengths from 0.5 to 20 μm can be characterized, denoting five octaves of spectral range. Using ptychography, we retrieve the temporal profiles of both the probe pulse and the switch. To demonstrate this approach, we measure ultrashort pulses from a titanium-sapphire (Ti-Sa) amplifier, which are compressed using a hollow core fiber setup, as well as infrared to mid-infrared pulses generated from an optical parametric amplifier (OPA). The characterized pulses are centered at wavelengths of 0.77, 1.53, 1.75, 4, and 10 μm, down to sub-two optical cycles duration, exceeding an octave of bandwidth, and with energy as low as a few nanojoules.

Lower C-reactive protein and IL-6 associated with vegetarian diets are mediated by BMI

BACKGROUND AND AIMS

The mechanism by which vegetarian diets are associated with less inflammation is not clear. We investigated the role of BMI as a mediator in the relationship between vegetarian diet and concentrations of C-reactive protein (CRP), and the cytokines IL-6, IL-10 and TNF-α.

METHODS AND RESULTS

We used data from participants of the Adventist Health Study 2 (AHS-2) Calibration (n = 893) and Biological Manifestations of Religion (n = 478) sub-studies. Vegetarian diet variations were determined based on reported intake of animal products assessed by FFQ. Combining all participants, the proportion of non-vegetarians (NVs), partial vegetarians (PVs), lacto-ovo vegetarians (LOVs), and strict vegetarians (SVs) was 44%, 16%, 31%, and 9%, respectively. NV and PV participants were older than other dietary groups, and non-vegetarians had the highest BMI. Mediation analyses supported the mediating effect of BMI in associations of vegetarian diet with CRP (p < 0.001 each for PV, LOV and SV), and with IL-6 (p < 0.05 each for PV, LOV and SV). Mediation by BMI was not evident between vegetarian diet and the biomarkers IL-10 and TNF-α. A direct pathway was significant only in the association between strict vegetarians and CRP (p = 0.017).

CONCLUSION

The lower CRP and IL-6 concentrations among vegetarians may be mediated by BMI.

FDC:TFH Interactions within Cervical Lymph Nodes of SIV-Infected Rhesus Macaques

Cerebrospinal fluid (CSF) drains via the lymphatic drainage pathway. This lymphatic pathway connects the central nervous system (CNS) to the cervical lymph node (CLN). As the CSF drains to CLN via the dural and nasal lymphatics, T cells and antigen presenting cells pass along the channels from the subarachnoid space through the cribriform plate. Human immunodeficiency virus (HIV) may also egress from the CNS along this pathway. As a result, HIV egressing from the CNS may accumulate within the CLN. Towards this objective, we analyzed CLNs isolated from rhesus macaques that were chronically-infected with simian immunodeficiency virus (SIV). We detected significant accumulation of SIV within the CLNs. SIV virion trapping was observed on follicular dendritic cells (FDCs) localized within the follicular regions of CLNs. In addition, SIV antigens formed immune complexes when FDCs interacted with B cells within the germinal centers. Subsequent interaction of these B cells with CD4+ T follicular helper cells (TFHs) resulted in infection of the latter. Of note, 73% to 90% of the TFHs cells within CLNs were positive for SIV p27 antigen. As such, it appears that not only do the FDCs retain SIV they also transmit them (via B cells) to TFHs within these CLNs. This interaction results in infection of TFHs in the CLNs. Based on these observations, we infer that FDCs within the CLNs have a novel role in SIV entrapment with implications for viral trafficking.

Spinal cord injury with central cord syndrome from surfing

Introduction

Central cord syndrome (CCS) is an injury to the center of the spinal cord. It is well known as a hyperextension injury, but it has never been described as a surfing injury. Our report describes this injury in detail.

Case presentation

A 35-year-old male novice surfer presented to the emergency department with acute tetraplegia following falling off his surfboard and hitting sea floor at a shallow beach break. He was rescued by a fellow surfer while floating in the sea and unable to raise his head above sea level. Upon arrival at the hospital, tetraplegia and sensory deficits were noted. Radiological investigations showed advanced spinal stenosis at C4-6 levels. T2 magnetic resonance imaging (MRI) demonstrated myelopathy at C5-C6 level. He was diagnosed as having central cord syndrome, treated conservatively, and regained near full neurologic recovery after a month of rehabilitation.

Discussion

Unique sport activities lead to unique injuries. It is important to accurately describe these injuries in order to create protective measures against them. Neurologic injuries in surfers are uncommon. With low-energy trauma, surfer's myelopathy is still the most common diagnosis, but central cord syndrome should be in the differential diagnosis.

Comprehensive analysis of serum and innate immune cells revealed age-related alternations

Age-related alterations in immunity have been linked to increased incidence of infections and decreased responses to vaccines in the aging population. These immune dysfunctions, termed immunosenescence, have been linked to the intricate interactions between the innate and adaptive immune responses. The impact of aging on innate immunity remains an open question. We performed a comprehensive analysis of serum and peripheral blood mononuclear cells (PMBCs) isolated from healthy non-frail adults (≤ 40 years) and old individuals (≥ 65 years). The basal level of circulating inflammatory cytokines and chemokines were measured, as well as transcriptome data was analyzed for both ex vivo and agonist stimulated DCs and monocyte subsets. We observed that sorted DC (BDCA-1, -2, and -3) and monocyte (CD14+CD16−,CD14dimCD16+, and CD14+CD16+) subsets were primarily distinct and have unique transcriptional profiles. Under ex vivo conditions, innate subsets did not reveal significant age-related alternations; however, agonist stimulated-monocytes from adults and old subjects did show differences at the transcriptional and functional levels. After stimulation of TLR4 (LPS), TLR7/8 (CLO97), and RIGI (5′-pppRNA), we observed higher production of interferons, CCL8, CCL20, and IL1B in monocytes isolated from adults compared to old individuals. Pathway analysis revealed that innate agonists induced functional pathways in monocytes isolated from both adults and old subjects. Overall, our data reveals a wide range of potential age-associated alternations in pattern recognition receptors (PRRs) signaling and have implications for strategies to enhance the immune response in the context of infection or immunization.

Mechanisms of T follicular helper (Tfh) impairment in chronic HIV infection

Human immunodeficiency virus (HIV) infects millions of people worldwide. In secondary lymphoid organs, site where the anti-HIV immune response is mounted, the virus has been shown to induce a predominant dysregulation and disturbance of the microvenvironment. Previous work in our laboratory has identified the lack of protective anti-HIV antibodies in patients to be due, at least in part, to an inadequate T follicular helper (Tfh) cell help to germinal center (GC) B cells in draining lymph nodes through impaired PD-1/PD-L1 interactions. Since the mechanism of this impairment is not yet fully elucidated, we have used our co-culture assay followed by a unique gene array analysis to screen for key molecular pathways that could be accountable for the difference between helper programs in Tfh cells of HIV positive and negative individuals. The major driver of gene profile clustering was observed within Tfh proliferation programs as well as infection status. Gene set enrichment analysis included repair mechanisms, cell cycle regulation, metabolism, signal transduction and co-stimulation in the top 10 enriched pathways. Careful examination of gene fold changes in proliferating vs non-proliferating Tfh cells between healthy and HIV individuals showed a decrease with HIV, in immune regulatory gene expression such as the transcription factor c-maf and its mediators, responsible for Tfh differentiation, development, survival and performance. Investigating this pathway would contribute to a better understanding of the HIV-mediated dysregulation.