Plaque Reduction Research Articles

Novel Role of Endothelial CD47 in the Regulation of Pathogenesis of Coronary Artery Disease

Background: The anti-phagocytic molecule CD47 is upregulated in atherosclerotic plaques of patients with CVD. However, the role of endothelial cell-specific expression of CD47 in the pathogenesis and progression of atherosclerosis has not yet been fully defined. Kojima et.al. described atheroprotective effect of anti-CD47 antibody by enhancing efferocytosis in atherosclerosis. In this study, we determined whether endothelial cell-specific CD47 regulates efferocytosis in atherosclerosis. Methods: Endothelial cell-specific, tamoxifen-inducible CD47knockout (CD47iECKO) mice were injected with a single dose of AAV-mutant PCSK9 via the tail vein. Susceptibility to atherosclerosis was evaluated in cross sections of the aortic sinus in mice fed Western Diet for 12 weeks. Using single-cell RNA sequencing and in vitro efferocytosis assays, we investigated the role of CD47 in regulating efferocytosis in an atherosclerotic mouse model. Results: Endothelial cell-specific deletion of CD47 led to a significant plaque reduction in the aortic sinus of athero-CD47iECKO mice. Cluster analysis and gene expression profiles of 20,000 aortic endothelial cells from athero-control and athero-CD47iECKO mice identified 10 major cell types from the integrated data: endothelial cells, vascular smooth muscle cells, fibroblasts, immune cells (B cells, T cells, macrophage), erythrocytes, oligodendrocytes cells, Schwann cells, and pericytes. After Western Diet intake, in the CD47iECKO group, a subpopulation of endothelial cells as well as fibroblasts, T-cells, B-cells, resident aortic macrophages, erythrocytes, oligodendrocytes, and pericytes were increased, while vascular smooth muscle cell numbers decreased. Using an in vitro efferocytosis assay on isolated primary endothelial cells from control and CD47iECKO mice, we observed CD47 deletion induced engulfment of apoptotic Jurkat cells, which had been exposed to BAY11-7082 (NF-κB inhibitor) to stimulate the apoptotic attributes. Quantitative PCR analyses showed that CD47 deletion increases the expression of efferocytosis receptor FasL, CX3CL1, Gpr132, MerTK, Scarb1, Sirpa, TSP1, and HMGB1. Conclusion: Our study indicates that genetic deletion of CD47 in endothelial cells attenuates atheroma progression by enhancing efferocytosis. This study also reveals phenotypic heterogenicity of endothelial cells at the single cell level during atherogenesis and provides a deeper understanding of endothelial cell biology in atherosclerosis that may facilitate the development of novel therapeutic interventions for this cardiovascular disease. NIH, AHA. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Seroprevalence of West Nile Virus in Tampa Bay Florida Patients Admitted to Hospital during 2020-2021 for Respiratory Symptoms.

West Nile virus (WNV) is an arbovirus spread primarily by Culex mosquitoes, with humans being a dead-end host. WNV was introduced to Florida in 2001, with 467 confirmed cases since. It is estimated that 80 percent of cases are asymptomatic, with mild cases presenting as a non-specific flu-like illness. Currently, detection of WNV in humans occurs primarily in healthcare settings via RT-PCR or CSF IgM when patients present with severe manifestations of disease including fever, meningitis, encephalitis, or acute flaccid paralysis. Given the short window of detectable viremia and requirement for CSF sampling, most WNV infections never receive an official diagnosis. This study utilized enzyme-linked immunosorbent assay (ELISA) to detect WNV IgG antibodies in 250 patient serum and plasma samples collected at Tampa General Hospital during 2020 and 2021. Plaque reduction neutralization tests were used to confirm ELISA results. Out of the 250 patients included in this study, 18.8% of them were IgG positive, consistent with previous WNV exposure. There was no relationship between WNV exposure and age or sex.

Monkeypox Virus Neutralizing Antibodies at Six Months from Mpox Infection: Virologic Factors Associated with Poor Immunologic Response.

A natural monkeypox virus infection may not induce sufficient neutralizing antibody responses in a subset of healthy individuals. The aim of this study was to evaluate monkeypox virus-neutralizing antibodies six months after infection and to assess the virological factors predictive of a poor immunological response. Antibodies were assessed using a plaque reduction neutralization test at six months from mpox infection; mpox cutaneous, oropharyngeal, and anal swabs, semen, and plasma samples were tested during infection. Overall, 95 people were included in the study; all developed detectable antibodies. People who were positive for the monkeypox virus for more days had higher levels of antibodies when considering all tested samples (p = 0.029) and all swabs (p = 0.005). Mpox cycle threshold values were not predictive of antibody titers. This study found that the overall days of monkeypox virus detection in the body, irrespective of the viral loads, were directly correlated with monkeypox virus neutralizing antibodies at six months after infection.

Extracellular and intracellular antiviral effects of ultraviolet A against severe acute respiratory syndrome coronavirus-2 are variant-independent

Under controlled settings, narrow-band ultraviolet A (UVA) exposure exerts antiviral effects both in vivo and in vitro. The effect is thought to be mediated via direct effect on viral particles and indirectly, by modulation of metabolic pathways of host cells. We aimed to explore the extracellular and intracellular antiviral effects of UVA exposure against Alpha, Beta, and Delta variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). MethodsVero E6 kidney normal epithelial cells and human tracheal epithelial cells were infected with Alpha, Beta, and Delta variants in a BSL-3 laboratory. To assess extracellular effects, SARS-CoV-2 variants were directly exposed to a single dose of UVA prior to infection of the host cells (Vero E6 kidney normal epithelial cells and human tracheal epithelial cells) The intracellular effects of UVA were assessed by first infecting the cells with SARS-CoV-2 variants followed by UVA treatment of infected cell monolayers. Efficacy was quantified by both plaque reduction assay and quantitative real-time polymerase chain reaction. Additionally, transcriptomic analysis was performed on exposed Vero E6 cells to assess differentially expressed genes and canonical pathways as compared to controls. ResultsSARS-CoV-2 Alpha, Beta and Delta variants are susceptible to UVA exposure prior to infection of Vero E6 cells. Importantly, the UVA-driven reduction in Delta variant load could be reproduced in human primary tracheal cells. Beta and Delta variants load also significantly decreased during Vero E6 cells intracellular experiments. UVA-driven reductions in viral loads ameliorate several host metabolic pathways, including canonical pathways related to viral infection and interferon signaling. ConclusionNarrow-band UVA exhibits both extracellular effects on SARS-CoV-2 viral particles and intracellular effects on infected cells with SARS-CoV-2. Efficacy appears to be variant independent.

Sangbaipi decoction exerted in vitro and in vivo anti-influenza effect through inhibiting viral proteins

Headings ethnopharmacological relevanceSangbaipi Decoction (SBPD) is an effective treatment for lung diseases caused by phlegm-heat obstruction according to Jingyue Quanshu, and soothes panting by purging the lung meridian. It is composed of anti-pyretic herbs (e.g., Scutellaria baicalensis Georgi and Coptis chinensis Franch.) and antitussive herbs (e.g., Cortex Mori and Armeniacae Semen Amarum). Therefore, we hypothesized that SBPD has therapeutic effects on lung injury caused by influenza virus. Aim of the studyThis study aimed to explore anti-influenza activity, active components, and mechanisms of SBPD. Materials and methodsThe anti-influenza activities of SBPD were determined in 48 h drug-treated MDCK cell model using CPE and plaque reduction assays, and 24 h drug-treated A549 cells using qRT-PCR. The in vivo efficacy of SBPD (1.0 g/kg/day and 0.5 g/kg/day) was evaluated in PR8 infected BALB/c mice. The chemical component was assessed through HPLC-Q-TOF MS/MS analysis. Network pharmacology was built via TCMSP, GeneCards, DisgeNet, OMIM, DrugBank databases, and Cytoscape software. Additionally, TOA, HI and NAI assays were employed to investigate impact on the virus replication cycle with different concentrations of SBPD (2.5 mg/mL, 1.25 mg/mL, or 0.625 mg/mL). ResultsIn MDCK infected with viruses A/PR/8/34, A/Hong Kong/1/68, or A/California/4/2009, the IC50 values of SBPD were 0.80 mg/mL, 1.20 mg/mL, and 1.25 mg/mL. In A549 cells, SBPD treatment reduced cytokine expression (e.g., TNF-α, IL-6, IL-1β) (p < 0.05). In PR8 infected BALB/c mice, SBPD improved the survival rate of infected mice, reduced lung index (p < 0.05), protected lung tissue from pathological damage, and regulated cytokine overexpression (p < 0.05). 29 components of SBPD were identified in SBPD treated mouse serum including some phytochemicals targeting influenza proteins. HI and NAI assays suggested the potential antiviral mechanism of SBPD through inhibition of HA and NA. ConclusionThis study is the first to demonstrate the anti-influenza and the anti-inflammatory effects of SBPD in vitro and in vivo. Its major anti-influenza phytochemicals were explored and its inhibitory effects on HA and NA protein were proved. It provides more options for anti-influenza drug discovery.

Transcranial Magneto-Acoustic Stimulation Protects Synaptic Rehabilitation from Amyloid-Beta Plaques via Regulation of Microglial Functions.

Transcranial magneto-acoustic stimulation (TMAS), which is characterized by high spatiotemporal resolution and high penetrability, is a non-invasive neuromodulation technology based on the magnetic-acoustic coupling effect. To reveal the effects of TMAS treatment on amyloid-beta (Aβ) plaque and synaptic plasticity in Alzheimer's disease, we conducted a comparative analysis of TMAS and transcranial ultrasound stimulation (TUS) based on acoustic effects in 5xFAD mice and BV2 microglia cells. We found that the TMAS-TUS treatment effectively reduced amyloid plaque loads and plaque-associated neurotoxicity. Additionally, TMAS-TUS treatment ameliorated impairments in long-term memory formation and long-term potentiation. Moreover, TMAS-TUS treatment stimulated microglial proliferation and migration while enhancing the phagocytosis and clearance of Aβ. In 5xFAD mice with induced microglial exhaustion, TMAS-TUS treatment-mediated Aβ plaque reduction, synaptic rehabilitation improvement, and the increase in phospho-AKT levels were diminished. Overall, our study highlights that stimulation of hippocampal microglia by TMAS treatment can induce anti-cognitive impairment effects via PI3K-AKT signaling, providing hope for the development of new strategies for an adjuvant therapy for Alzheimer's disease.

Impact of Cocoa Seed Extract Toothpaste on Plaque Reduction in Pediatric Populations

Plaque is a soft deposit that forms a helical biofilm layer and attached tightly to the tooth surface, in which its presence requiring the use of specific control agents. The safest and most effective plaque control is to use a toothbrush and toothpaste. On the other hand, extract from Theobroma cacao L. seeds contains antioxidant and antibacterial secondary metabolites which could act as a toothpaste active agent. The aim of this research was to determine the impact of Theobroma cacao L. seeds-added toothpaste in reducing plaque index of among children. This is a non-blinding clinical experiment with a pre-test and post-test research design. The research subjects were 30 healthy children aged 8-10 years which were randomly divided into three arms (treatment and control). The results revealed that Theobroma cacao L. extract used as the active ingredient contained contains phenolics, tannins, flavonoids, terpenoids, saponins, and alkaloids. Significantly higher plaque index reductions were observed among children treated with toothpaste containing 1% (mean difference=2.060; p=0.06) as compared to control. In conclusion, the Theobroma cacao L. seeds-added toothpaste could significantly reduce plaque index among healthy children.

Ligand-Free Silver Nanoparticles: An Innovative Strategy against Viruses and Bacteria.

The spread of antibiotic-resistant bacteria and the rise of emerging and re-emerging viruses in recent years constitute significant public health problems. Therefore, it is necessary to develop new antimicrobial strategies to overcome these challenges. Herein, we describe an innovative method to synthesize ligand-free silver nanoparticles by Pulsed Laser Ablation in Liquid (PLAL-AgNPs). Thus produced, nanoparticles were characterized by total X-ray fluorescence, zeta potential analysis, transmission electron microscopy (TEM), and nanoparticle tracking analysis (NTA). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate the nanoparticles' cytotoxicity. Their potential was evaluated against the enveloped herpes simplex virus type 1 (HSV-1) and the naked poliovirus type 1 (PV-1) by plaque reduction assays and confirmed by real-time PCR and fluorescence microscopy, showing that nanoparticles interfered with the early stage of infection. Their action was also examined against different bacteria. We observed that the PLAL-AgNPs exerted a strong effect against both methicillin-resistant Staphylococcus aureus (S. aureus MRSA) and Escherichia coli (E. coli) producing extended-spectrum β-lactamase (ESBL). In detail, the PLAL-AgNPs exhibited a bacteriostatic action against S. aureus and a bactericidal activity against E. coli. Finally, we proved that the PLAL-AgNPs were able to inhibit/degrade the biofilm of S. aureus and E. coli.

Antibodies Induced by Smallpox Vaccination after at Least 45 Years Cross-React with and In Vitro Neutralize Mpox Virus: A Role for Polyclonal B Cell Activation?

To evaluate whether antibodies specific for the vaccinia virus (VV) are still detectable after at least 45 years from immunization. To confirm that VV-specific antibodies are endowed with the capacity to neutralize Mpox virus (MPXV) in vitro. To test a possible role of polyclonal non-specific activation in the maintenance of immunologic memory. Sera were collected from the following groups: smallpox-vaccinated individuals with or without latent tuberculosis infection (LTBI), unvaccinated donors, and convalescent individuals after MPXV infection. Supernatant of VV- or MPXV-infected Vero cells were inactivated and used as antigens in ELISA or in Western blot (WB) analyses. An MPXV plaque reduction neutralization test (PRNT) was optimized and performed on study samples. VV- and PPD-specific memory T cells were measured by flow cytometry. None of the smallpox unvaccinated donors tested positive in ELISA or WB analysis and their sera were unable to neutralize MPXV in vitro. Sera from all the individuals convalescing from an MPXV infection tested positive for anti-VV or MPXV IgG with high titers and showed MPXV in vitro neutralization capacity. Sera from most of the vaccinated individuals showed IgG anti-VV and anti-MPXV at high titers. WB analyses showed that positive sera from vaccinated or convalescent individuals recognized both VV and MPXV antigens. Higher VV-specific IgG titer and specific T cells were observed in LTBI individuals. ELISA and WB performed using supernatant of VV- or MPXV-infected cells are suitable to identify individuals vaccinated against smallpox at more than 45 years from immunization and individuals convalescing from a recent MPXV infection. ELISA and WB results show a good correlation with PRNT. Data confirm that a smallpox vaccination induces a long-lasting memory in terms of specific IgG and that antibodies raised against VV may neutralize MPXV in vitro. Finally, higher titers of VV-specific antibodies and higher frequency of VV-specific memory T cells in LTBI individuals suggest a role of polyclonal non-specific activation in the maintenance of immunologic memory.

Utility of accessible SARS-CoV-2 specific immunoassays in vaccinated adults with a history of advanced HIV infection

Accessible SARS-CoV-2-specific immunoassays may inform clinical management in people with HIV, particularly in case of persisting immunodysfunction. We prospectively studied their application in vaccine recipients with HIV, purposely including participants with a history of advanced HIV infection. Participants received one (n = 250), two (n = 249) or three (n = 42) doses of the BNT162b2 vaccine. Adverse events were documented through questionnaires. Sample collection occurred pre-vaccination and a median of 4 weeks post-second dose and 14 weeks post-third dose. Anti-spike and anti-nucleocapsid antibodies were measured with the Roche Elecsys chemiluminescence immunoassays. Neutralising activity was evaluated using the GenScript cPass surrogate virus neutralisation test, following validation against a Plaque Reduction Neutralization Test. T-cell reactivity was assessed with the Roche SARS-CoV-2 IFNγ release assay. Primary vaccination (2 doses) was well tolerated and elicited measurable anti-spike antibodies in 202/206 (98.0%) participants. Anti-spike titres varied widely, influenced by previous SARS-CoV-2 exposure, ethnicity, intravenous drug use, CD4 counts and HIV viremia as independent predictors. A third vaccine dose significantly boosted anti-spike and neutralising responses, reducing variability. Anti-spike titres > 15 U/mL correlated with neutralising activity in 136/144 paired samples (94.4%). Three participants with detectable anti-S antibodies did not develop cPass neutralising responses post-third dose, yet displayed SARS-CoV-2 specific IFNγ responses. SARS-CoV-2 vaccination is well-tolerated and immunogenic in adults with HIV, with responses improving post-third dose. Anti-spike antibodies serve as a reliable indicator of neutralising activity. Discordances between anti-spike and neutralising responses were accompanied by detectable IFN-γ responses, underlining the complexity of the immune response in this population.

Comparative effectiveness of Propolis with chlorhexidine mouthwash on gingivitis – a randomized controlled clinical study

BackgroundTo assess and compare the effectiveness of propolis mouthwash with chlorhexidine mouthwash in the reduction of plaque and gingivitis.MethodsA single centre, latin-square cross-over, double masked, randomized controlled clinical trial was conducted on 45 chronic generalized gingivitis subjects who were chosen from the dental clinic of MAHSA University, Malaysia. A total of 45 subjects were randomly assigned into one of the three different groups (n = 15 each) using a computer-generated random allocation sequence: Group A Propolis mouthwash; Group B Chlorhexidine mouthwash; and Group C Placebo mouthwash. Supragingival plaque and gingival inflammation were assessed by full mouth Plaque index (PI) and gingival index (GI) at baseline and after 21 days. The study was divided into three phases, each phase lasted for 21 days separated by a washout period of 15 days in between them. Groups A, B and C were treated with 0.2% Propolis, Chlorhexidine, and Placebo mouthwash, respectively, in phase I. The study subjects were instructed to use the assigned mouthwash twice daily for 1 min for 21 days. On day 22nd, the subjects were recalled for measurement of PI and GI. After phase I, mouthwash was crossed over as dictated by the Latin square design in phase II and III.ResultsAt baseline, intergroup comparison revealed no statistically significant difference between Groups A, B and C (p > 0.05). On day 21, one-way ANOVA revealed statistically significant difference between the three groups for PI (p < 0.001) and GI (p < 0.001). Bonferroni post-hoc test showed statistically significant difference between Propolis and Chlorhexidine mouthwash (P < 0.001), with higher reduction in the mean plaque and gingival scores in propolis group compared to chlorhexidine and placebo groups.ConclusionsPropolis mouthwash demonstrated significant improvement in gingival health and plaque reduction. Thus, it could be used as an effective herbal mouthwash alternative to chlorhexidine mouthwash.Trial registrationThe trial was retrospectively registered on 25/07/2019 at clinicaltrials.gov and its identifier is NCT04032548.

Cynomolgus macaques as a translational model of human immune responses to yellow fever 17D vaccination.

The non-human primate (NHP) model (specifically rhesus and cynomolgus macaques) has facilitated our understanding of the pathogenic mechanisms of yellow fever (YF) disease and allowed the evaluation of the safety and efficacy of YF-17D vaccines. However, the accuracy of this model in mimicking vaccine-induced immunity in humans remains to be fully determined. We used a systems biology approach to compare hematological, biochemical, transcriptomic, and innate and antibody-mediated immune responses in cynomolgus macaques and human participants following YF-17D vaccination. Immune response progression in cynomolgus macaques followed a similar course as in adult humans but with a slightly earlier onset. Yellow fever virus neutralizing antibody responses occurred earlier in cynomolgus macaques [by Day 7[(D7)], but titers > 10 were reached in both species by D14 post-vaccination and were not significantly different by D28 [plaque reduction neutralization assay (PRNT)50 titers 3.6 Log vs 3.5 Log in cynomolgus macaques and human participants, respectively; P = 0.821]. Changes in neutrophils, NK cells, monocytes, and T- and B-cell frequencies were higher in cynomolgus macaques and persisted for 4 weeks versus less than 2 weeks in humans. Low levels of systemic inflammatory cytokines (IL-1RA, IL-8, MIP-1α, IP-10, MCP-1, or VEGF) were detected in either or both species but with no or only slight changes versus baseline. Similar changes in gene expression profiles were elicited in both species. These included enriched and up-regulated type I IFN-associated viral sensing, antiviral innate response, and dendritic cell activation pathways D3-D7 post-vaccination in both species. Hematological and blood biochemical parameters remained relatively unchanged versus baseline in both species. Low-level YF-17D viremia (RNAemia) was transiently detected in some cynomolgus macaques [28% (5/18)] but generally absent in humans [except one participant (5%; 1/20)].IMPORTANCECynomolgus macaques were confirmed as a valid surrogate model for replicating YF-17D vaccine-induced responses in humans and suggest a key role for type I IFN.

Effectiveness of Moringa oleifera Mouthwash in Young Adults as an Anti Plaque Agent – An Interventional Study

Background: Periodontitis is a chronic inflammatory disease affecting the oral cavity’s supportive structures, including gums and surrounding bone. Herbal mouthwashes have phytopharmacological agents such as Moringa oleifera (MO), and the use of herbal mouthwash has increased. Moringa mouthwash has potential for oral health due to its biocompatibility and anti-inflammatory effect. This study compares the effect of chlorhexidine gluconate (CHX) and moringa mouthwash on plaque and its reduction. Methodology: The in vitro tests included the determination of minimum inhibitory concentration using broth dilution and agar diffusion. This interventional study included 25 individuals with more than 1 plaque score. The study was conducted for 2 months with a washout period of 2 weeks between the use of both mouthwashes. The Quigley–Hein Plaque Index of the study subjects was recorded at the designated baseline and after 28 days of use throughout the study period. The statistical test used was the Wilcoxon signed-rank test, and the level of significance was considered to be &lt;0.05. Results: The results showed that the reduction in the mean plaque scores from baseline to day 28 was statistically significant in the moringa-based mouthwash. Similarly, the index scores showed a statistically significant reduction following the use of the moringa-based mouthwash when compared with the gold-standard chlorhexidine mouthwash with P = 0.00. The comparison showed that MO offered the same improvement as CHX. Conclusion: The current study aimed to provide an insight role of MO mouthwash as a possible adjunctive oral hygiene aid and its inhibitory effect on plaque reduction when compared to CHX.

Serologic Survey of Selected Arthropod-Borne Pathogens in Free-Ranging Snowshoe Hares (Lepus americanus) Captured in Northern Michigan, USA.

Snowshoe hares (Lepus americanus) in the Upper Peninsula (UP) of Michigan, USA, occupy the southern periphery of the species' range and are vulnerable to climate change. In the eastern UP, hares are isolated by the Great Lakes, potentially exacerbating exposure to climate-change-induced habitat alterations. Climate change is also measurably affecting distribution and prevalence of vector-borne pathogens in North America, and increases in disease occurrence and prevalence can be one signal of climate-stressed wildlife populations. We conducted a serosurvey for vector-borne pathogens in snowshoe hares that were captured in the Hiawatha National Forest in the eastern UP of Michigan, USA, 2016-2017. The most commonly detected antibody response was to the mosquito-borne California serogroup snowshoe hare virus (SSHV). Overall, 24 (51%) hares screened positive for SSHV antibodies and of these, 23 (96%) were confirmed positive by plaque reduction neutralization test. We found a positive association between seroprevalence of SSHV and live weight of snowshoe hares. Additionally, we detected a significant effect of ecological land type group on seroprevalence of SSHV, with strong positive support for a group representing areas that tend to support high numbers of hares (i.e., acidic mineral containing soils with cedar, mixed swamp conifers, tamarack and balsam fir as common overstory vegetation). We also detected and confirmed antibodies for Jamestown Canyon virus and Silverwater virus in a single hare each. We did not detect antibodies to other zoonotic vector-borne pathogens, including Lacrosse encephalitis virus, West Nile virus, Borrelia burgdorferi, Powassan virus, and Francisella tularensis. These results provide a baseline for future serological studies of vector-transmitted diseases that may increase climate vulnerability of snowshoe hares in the UP of Michigan, as well as pose a climate-related zoonotic risk.

Functional and Multi-Omics Effects of an Optimized CRISPR-Mediated FURIN Depletion in U937 Monocytes.

The pro-protein convertase FURIN (PCSK3) is implicated in a wide range of normal and pathological biological processes such as infectious diseases, cancer and cardiovascular diseases. Previously, we performed a systemic inhibition of FURIN in a mouse model of atherosclerosis and demonstrated significant plaque reduction and alterations in macrophage function. To understand the cellular mechanisms affected by FURIN inhibition in myeloid cells, we optimized a CRISPR-mediated gene deletion protocol for successfully deriving hemizygous (HZ) and nullizygous (NZ) FURIN knockout clones in U937 monocytic cells using lipotransfection-based procedures and a dual guide RNA delivery strategy. We observed differences in monocyte and macrophage functions involving phagocytosis, lipid accumulation, cell migration, inflammatory gene expression, cytokine release patterns, secreted proteomics (cytokines) and whole-genome transcriptomics between wild-type, HZ and NZ FURIN clones. These studies provide a mechanistic basis on the possible roles of myeloid cell FURIN in cardiovascular disorders.

Age-Related Differences in Neutralizing Antibody Responses against SARS-CoV-2 Delta and Omicron Variants in 151 SARS-CoV-2-Naïve Metropolitan Residents Boosted with BNT162b2.

Although age negatively correlates with vaccine-induced immune responses, whether the vaccine-induced neutralizing effect against variants of concern (VOCs) substantially differs across age remains relatively poorly explored. In addition, the utility of commercial binding assays developed with the wild-type SARS-CoV-2 for predicting the neutralizing effect against VOCs should be revalidated. We analyzed 151 triple-vaccinated SARS-CoV-2-naïve individuals boosted with BNT162b2 (Pfizer-BioNTech). The study population was divided into young adults (age < 30), middle-aged adults (30 ≤ age < 60), and older adults (age ≥ 60). The plaque reduction neutralization test (PRNT) titers against Delta (B.1.617.2) and Omicron (B.1.1.529) variants were compared across age. Antibody titers measured with commercial binding assays were compared with PRNT titers. Age-related decline in neutralizing titers was observed for both Delta and Omicron variants. Neutralizing titers for Omicron were lower than those against Delta in all ages. The multiple linear regression model demonstrated that duration from third dose to sample collection and vaccine types were also significant factors affecting vaccine-induced immunity along with age. The correlation between commercial binding assays and PRNT was acceptable for all age groups with the Delta variant, but relatively poor for middle-aged and older adults with the Omicron variant due to low titers. This study provides insights into the age-related dynamics of vaccine-induced immunity against SARS-CoV-2 VOCs, corroborating the need for age-specific vaccination strategies in the endemic era where new variants continue to evolve. Moreover, commercial binding assays should be used cautiously when estimating neutralizing titers against VOCs, particularly Omicron.

Cepharanthine inhibits influenza A virus replication by impairing viral polymerase activity and regulating influenza-induced immune response

BackgroundCepharanthine (CEP), a natural bis-benzylisoquinoline alkaloid extracted from the plant Stephania cephalantha Hayata, has been widely used to treat several acute and chronic diseases. However, its antiviral potential against influenza A virus (IAV) infection remains unknown. PurposeThe study aims to assess the antiviral and immunomodulatory effects of CEP in vivo and in vitro and investigate its underlying antiviral mechanisms. MethodsAntiviral and anti-inflammatory activities of CEP were assessed in MDCK, A549 and RAW264.7 cells infected with influenza virus. Proinflammatory cytokine levels were measured by qRT-PCR and ELISA. The anti-influenza effect and underlying antiviral mechanism of CEP were mainly determined by MTT assay, plaque reduction assay, time-of-addition and mini-replicon assay. The inhibition of CEP on IAV-induced activation of innate immune signaling was detected by western blotting. Furthermore, BALB/c mice were infected intranasally with A/PR/8/34 (H1N1) virus and treated with CEP (60, 30, 15 mg/kg/d) or oseltamivir (60 mg/kg/d). The changes in body weight, survival rates, viral titers, proinflammatory cytokine levels and pathological parameters were detected. ResultsCEP exhibited antiviral effects against multiple IAV strains, while also demonstrating anti-inflammatory effects in influenza virus-infected RAW264.7 and A549 cells. The results of the mechanism study indicated that CEP effectively suppressed IAV replication by limiting viral polymerase activity. On the other hand, CEP could modulate pro-inflammatory responses via inhibition of janus kinase/signal transducer and activator of transcription/ nuclear factor kappa B (JAK/STAT/NF‑κB) signaling pathways involved in influenza virus pathogenesis. Treatment of mice with CEP improved the survival rate and body weight of influenza virus-infected mice, reduced viral titers and alleviated influenza virus-induced pathological damage and inflammation in mouse lung tissue. ConclusionCollectively, the anti-influenza virus property of CEP was a result of inhibiting viral polymerase activity and preventing virus-induced excessive inflammation, highlighting it might be an oral medication for the treatment of IAV infection.

Yellow fever neutralizing antibody seroprevalence proportion and titers in previously vaccinated adults with chronic kidney disease

Studies on yellow fever vaccine (YF) in chronic kidney disease (CKD) patients are scarce. This cross-sectional study aimed to evaluate YF neutralizing antibody seroprevalence and titers in previously vaccinated adults with CKD, on dialysis (D-CKD) or not (ND-CKD), compared to healthy persons. The micro Plaque Reduction Neutralization-Horseradish Peroxidase (μPRN-HP) test was used. Antibody titers were expressed as the reciprocal of the highest dilution that neutralized the challenge virus by 50 % (μPRN50). Seropositivity cut-off was set at ≥ 1:100. We included 153 participants: 46 ND-CKD, 50 D-CKD and 57 healthy adults. Median ages were 58.3, 55 and 52.2 years, respectively. Median time since YF vaccination was 22.3, 18.5 and 48.3 months respectively. There were no statistically significant differences in YF seroprevalence and neutralizing antibodies titers among groups: 100 % of ND-CKD; 96 % of D-CKD and 100 % of healthy participants were seropositive. Geometric mean titers (GMT) were 818.5, 683.0 and 665.5, respectively (p = 0.289).

Evaluation of humoral immune response after yellow fever infection: an observational study on patients from the 2017-2018 sylvatic outbreak in Brazil.

Between 2016 and 2018, Brazil experienced major sylvatic yellow fever (YF) outbreaks that caused hundreds of casualties, with Minas Gerais (MG) being the most affected state. These outbreaks provided a unique opportunity to assess the immune response triggered by the wild-type (WT) yellow fever virus (YFV) in humans. The plaque reduction neutralization test (PRNT) is currently the standard method to assess the humoral immune response to YFV by measuring neutralizing antibodies (nAbs). The present study aimed to evaluate the humoral immune response of patients from the 2017-2018 sylvatic YF outbreak in MG with different disease outcomes by using PRNTs with a WT YFV strain, isolated from the 2017-2018 outbreak, and a vaccine YFV strain. Samples from naturally infected YF patients were tested, in comparison with healthy vaccinees. Results showed that both groups presented different levels of nAb against the WT and vaccine strains, and the levels of neutralization against the strains varied homotypically and heterotypically. Results based on the geometric mean titers (GMTs) suggest that the humoral immune response after a natural infection of YFV can reach higher levels than that induced by vaccination (GMT of patients against WT YFV compared to GMT of vaccinees, P < 0.0001). These findings suggest that the humoral immune responses triggered by the vaccine and WT strains of YFV are different, possibly due to genetic and antigenic differences between these viruses. Therefore, current means of assessing the immune response in naturally infected YF individuals and immunological surveillance methods in areas with intense viral circulation may need to be updated.IMPORTANCEYellow fever is a deadly febrile disease caused by the YFV. Despite the existence of effective vaccines, this disease still represents a public health concern worldwide. Much is known about the immune response against the vaccine strains of the YFV, but recent studies have shown that it differs from that induced by WT strains. The extent of this difference and the mechanisms behind it are still unclear. Thus, studies aimed to better understand the immune response against this virus are relevant and necessary. The present study evaluated levels of neutralizing antibodies of yellow fever patients from recent outbreaks in Brazil, in comparison with healthy vaccinees, using plaque reduction neutralization tests with WT and vaccine YFV strains. Results showed that the humoral immune response in naturally infected patients was higher than that induced by vaccination, thus providing new insights into the immune response triggered against these viruses.

The neutralization antibodies of SARS-CoV-2 during COVID-19 outbreak in Da Nang, Vietnam, July - August 2020

Beside molecular tests (realtime RT-PCR) which known as the golden key for SARS-CoV-2 confirmation, antibody test can be used to determine the responses in human antibody to SARS-CoV-2 and the result of plaque reduction neutralization test (PRNT) could identify the people who have been exposed with the SARS-CoV-2 and carried the neutralization antibody. Total 9936 samples were collected in 3 groups healthcare workers, inpatients (not related to COVID-19 before) and community in Da Nang city during July-August 2020. These cross sectional results showed that the rate of neutralization antibody in three groups in this research was 0.2%, in that, 0.1% in community, 0.2% in inpatient and 0.4% in healthcare workers. Follow-up study with 1253 paired sera of healthcare workers, the rate of SARS-CoV-2 neutralization antibody was determined as 2.1%. A downward trend of this neutralization antibody overtime has been shown in the study.