Respiratory Syncytial Virus (RSV) infections in children: recent concepts in immunopathogenesis and diagnostic dilemma

Respiratory viral infections are important cause of morbidity and mortality in early life. The relative influence of host and viral factors possibly contribute to the disease pathogenesis. Predisposing conditions like prematurity, Low birth weight and congenital heart diseases etc. have been incriminated in the disease progression. The development of cough, wheezing, and tachypnea, usually peaking on days 4 to 5, go parallel with host cytokine responses and viral load. Various host cytokines, chemokines and molecules involved in the immune response against RSV infection might be responsible for the outcome of the disease process. Nasopharyngeal aspirates (NPAs) from children (n = 349) between 2013-2017 were subjected for IL-17A, IFN-gamma, TNF-alpha, IL-10, IL-6 levels by CBA and MMP-9 and TIMP-1 levels by ELISA. The viral load in RSV positive samples and cytokine levels were correlated with the WHO criteria for acute lower respiratory tract illness (ALRTI). RSV viral load, Pro-inflammatory cytokine (TNF-alpha) levels in severe ALRTI patients were significantly higher than the ALRTI patients [p<0.001]. Whereas Th17 cytokine (IL-17) was found to be significantly higher (p<0.05) in ALRTI patients than severe patients. MMP-9 is secreted in higher levels in severe ALRTI patients (n = 77) in comparison to Acute LRTI patients (n = 35) with an increase of thirty seven fold (p<0.001). Thus, the study highlights the role of TNF -alpha, IL-17 and Th2 cytokine biasness in the pathogenesis of RSV disease with the possible contribution of higher MMP-9/TIMP-1 ratio as a bad prognostic marker towards disease severity. To study the gene expression of autophagy and mTOR signalling pathways in RSV infected children with ALRTI. Nasopharyngeal aspirate (NPA) samples (n = 145) from children suffering from ALRTI were subjected for detection of RSV (Oct 2019 to March 2020). Semi-quantitative gene expression analysis for 5 representative genes each of mTOR signalling and autophagy pathway were performed in respiratory tract epithelial cells using 25 RSV positive cases and 10 healthy controls subjects. Autophagy gene expression analysis revealed significant upregulation in NPC1 and ATG3 autophagy genes. mTOR, AKT1 and TSC1 genes of mTOR pathway were significantly down-regulated in RSV positive patients except RICTOR gene which was significantly upregulated. Thus, survival of RSV within autophagosome might have been facilitated by upregulation of autophagy and downregulation of mTOR signalling genes. To assess the impact of SARS-CoV2 pandemic on RSV, samples were collected from children with ALRTIs admitted to emergency, PICU and indoor admissions during pre-pandemic period (October 2019 to February 2020;n = 166) and during COVID-19 Pandemic (July 2021 to July 2022;n = 189, SARS-CoV2 negative). These NP swabs were analyzed for pdm InfA H1N1, InfA H3N2, Inf B, RSV, hMPV, hBoV, hRV, PIV-2 and PIV-3 by PCR. Higher proportion of children with ALRTIs have had virus/es isolated during pre-pandemic period than during pandemic period (p<0.001). During pre-pandemic period, significantly higher proportion of children had RSV positivity (p<0.001);and significantly lower positivity for hRV (p<0.05), hMPV (p<0.05), and hBoV (p <= 0.005). The occurrence of COVID-19 pandemic has significantly impacted the frequency and pattern of detection of RSV among hospitalized children with LRTIs. RSV Fusion protein plays a critical role in the entry of the virus into the host cell by initiating the fusion of host and viral membranes. It happens to be a target of neutralizing antibodies paving the way as a vaccine candidate. Hence effort was made to introduce point mutation in hRSV fusion protein which can confer stability in its prefusion form. In-silico a stable structure of RSV fusion protein was generated making it a potential vaccine candidate. The timely diagnosis of RSV infection in this population is important for initiating therapy and instituting appropriate infection prevention measures. Serological testing is not widely used for the diagnosis of RSV. C ll Cultures including shell vial culture were used for RSV diagnosis. However, culture approaches lack sensitivity, often quite significantly, compared to nucleic acid amplification assays for the diagnosis of RSV infections. Molecular multiplex assays now offer increased sensitivity for a more accurate diagnosis. However issues with the use of these types of commercial panel assays include the requirement for substantial training, quality systems, and infrastructure to maintain and run these assays and many a times identification of viruses where the true pathogenic potential of those multiple viruses are debatable. Studies are available with laboratory- developed nucleic acid amplification test systems for the detection of RSVA and RSVB in clinical specimens either by PCRbased technologies or RT-LAMP. Gene targets of laboratory-developed molecular assays point towards M gene and the N gene in RSVA and -B with the benefits of flexibility to modify assays when targets are under evolutionary pressure to change, as well as a perceived initial low cost to carry out testing.

AUTOPHAGY AND Acyl-CoA-BINDING PROTEIN INFLUENCE COVID-19 SEVERITY

Background: Autophagy, a cytosolic-structure degradation pathway, allows production of IL21 by CD4 T-cells and efficient cytolytic responses by CD8 T-cells. Autophagy is in part regulated by acyl-CoA-binding protein (ACBP) which has two functions. Intracellular ACBP favors autophagy, whereas secreted extracellular ACBP inhibits autophagy. Herein, we assessed whether autophagy and the ACBP pathway were associated with COVID-19 severity. Method(s): Through the BQC-19 Quebec biobank, somalogic proteomic analysis was performed on 5200 proteins in plasma samples collected between March 2020 and December 2021. Plasma from 903 patients (all data available) during the acute phase of COVID-19 were assessed. COVID-19 severity was stratified using WHO criteria. In vitro, ACBP intracellular levels, autophagy levels (LC3II) and IL21 production were assessed by flow in PBMCs after a 24h stimulation with IL6, phorbol myristate acetate (PMA)+ionomycin or lipopolysaccharide (LPS). Plasma levels of anti-SARS-CoV-2 (full spike protein or RBD) IgG were assessed by ELISA. Result(s): Median age of the cohort was 62 yo, 48% were female, 55% had comorbidities (see table). Increasing plasma levels of ACBP were found with severity (mild, moderate, severe and fatal groups having 5.3, 7.3, 9.5 and 10.6 RFU/50muL of plasma, respectively, p< 0.001 for all comparisons). Patients with comorbidities had higher plasma ACBP levels (7.4 vs 6.4 RFU/50muL, p< 0.001). Plasma ACBP levels were higher during the delta and omicron-variant periods (8.4 vs 6.8 RFU/50muL;p< 0.001). Plasma ACBP levels correlated with LC3II levels (r=0.51, P< 0.001) and IL6 (r=0.41, p< 0.001), but neither with markers IL1beta nor IL8. ACBP levels negatively correlated with IL21 levels (r=-0.27, p< 0.001), independently of age, sex, and severity. ACBP levels were not associated with levels of anti-SARS-CoV-2 IgG levels. In vitro, IL6 stimulation of healthy control PBMC induced extracellular ACBP release. Moreover, adding recombinant ACBP: 1) reduced autophagy in lymphocytes and monocytes upon polyclonal stimulation with PMA/ionomycin or LPS;2) reduced intracellular production of IL21 in T-cells after PMA/ ionomycin stimulation. Conclusion(s): Plasma ACBP levels were inversely linked with IL21 levels, suggesting that autophagy and IL21 allow control of SARS-CoV-2 infection, independently of the level of SARS-CoV-2 antibody secretion. ACBP is a targetable autophagy checkpoint and its extracellular inhibition may improve SARS-CoV-2 immune control. (Table Presented).

Autophagy Receptor p62 Regulates SARS-CoV-2-Induced Inflammation in COVID-19.

As autophagy can promote or inhibit inflammation, we examined autophagy-inflammation interplay in COVID-19. Autophagy markers in the blood of 19 control subjects and 26 COVID-19 patients at hospital admission and one week later were measured by ELISA, while cytokine levels were examined by flow cytometric bead immunoassay. The antiviral IFN-α and proinflammatory TNF, IL-6, IL-8, IL-17, IL-33, and IFN-γ were elevated in COVID-19 patients at both time points, while IL-10 and IL-1ß were increased at admission and one week later, respectively. Autophagy markers LC3 and ATG5 were unaltered in COVID-19. In contrast, the concentration of autophagic cargo receptor p62 was significantly lower and positively correlated with TNF, IL-10, IL-17, and IL-33 at hospital admission, returning to normal levels after one week. The expression of SARS-CoV-2 proteins NSP5 or ORF3a in THP-1 monocytes caused an autophagy-independent decrease or autophagy-inhibition-dependent increase, respectively, of intracellular/secreted p62, as confirmed by immunoblot/ELISA. This was associated with an NSP5-mediated decrease in TNF/IL-10 mRNA and an ORF3a-mediated increase in TNF/IL-1ß/IL-6/IL-10/IL-33 mRNA levels. A genetic knockdown of p62 mimicked the immunosuppressive effect of NSP5, and a p62 increase in autophagy-deficient cells mirrored the immunostimulatory action of ORF3a. In conclusion, the proinflammatory autophagy receptor p62 is reduced inacute COVID-19, and the balance between autophagy-independent decrease and autophagy blockade-dependent increase of p62 levels could affect SARS-CoV-induced inflammation.

Autophagy and SARS-CoV-2-Old Players in New Games.

At present it is well-defined that autophagy is a fundamental process essential for cell life but its pro-viral and anti-viral role has been stated out with the COVID pandemic. However, viruses in turn have evolved diverse adaptive strategies to cope with autophagy driven host defense, either by blocking or hijacking the autophagy machinery for their own benefit. The mechanisms underlying autophagy modulation are presented in the current review which summarizes the accumulated knowledge on the crosstalk between autophagy and viral infections, with a particular emphasizes on SARS-CoV-2. The different types of autophagy related to infections and their molecular mechanisms are focused in the context of inflammation. In particular, SARS-CoV-2 entry, replication and disease pathogenesis are discussed. Models to study autophagy and to formulate novel treatment approaches and pharmacological modulation to fight COVID-19 are debated. The SARS-CoV-2-autophagy interplay is presented, revealing the complex dynamics and the molecular machinery of autophagy. The new molecular targets and strategies to treat COVID-19 effectively are envisaged. In conclusion, our finding underline the importance of development new treatment strategies and pharmacological modulation of autophagy to fight COVID-19.

Lysosomal nanotoxicity: Impact of nanomedicines on lysosomal function.

Although several nanomedicines got clinical approval over the past two decades, the clinical translation rate is relatively small so far. There are many post-surveillance withdrawals of nanomedicines caused by various safety issues. For successful clinical advancement of nanotechnology, it is of unmet need to realize cellular and molecular foundation of nanotoxicity. Current data suggest that lysosomal dysfunction caused by nanoparticles is emerging as the most common intracellular trigger of nanotoxicity. This review analyzes prospect mechanisms of lysosomal dysfunction-mediated toxicity induced by nanoparticles. We summarized and critically assessed adverse drug reactions of current clinically approved nanomedicines. Importantly, we show that physicochemical properties have great impact on nanoparticles interaction with cells, excretion route and kinetics, and subsequently on toxicity. We analyzed literature on adverse reactions of current nanomedicines and hypothesized that adverse reactions might be linked with lysosomal dysfunction caused by nanomedicines. Finally, from our analysis it becomes clear that it is unjustifiable to generalize safety and toxicity of nanoparticles, since different particles possess distinct toxicological properties. We propose that the biological mechanism of the disease progression and treatment should be central in the optimization of nanoparticle design.

SARS-CoV-2 Nsp8 induces mitophagy by damaging mitochondria.

Autophagy plays an important role in the interaction between viruses and host cells. SARS-CoV-2 infection can disrupt the autophagy process in target cells. However, the precise molecular mechanism is still unknown. In this study, we discovered that the Nsp8 of SARS-CoV-2 could cause an increasing accumulation of autophagosomes by preventing the fusion of autophagosomes and lysosomes. From further investigation, we found that Nsp8 was present on mitochondria and can damage mitochondria to initiate mitophagy. The results of experiments with immunofluorescence revealed that Nsp8 induced incomplete mitophagy. Moreover, both domains of Nsp8 orchestrated their function during Nsp8-induced mitophagy, in which the N-terminal domain colocalized with mitochondria and the C-terminal domain induced auto/mitophagy. This novel finding expands our understanding of the function of Nsp8 in promoting mitochondrial damage and inducing incomplete mitophagy, which helps us to understand the etiology of COVID-19 as well as open up new pathways for creating SARS-CoV-2 treatment methods.

Characterization of Human Norovirus Nonstructural Protein NS1.2 Involved in the Induction of the Filamentous Endoplasmic Reticulum, Enlarged Lipid Droplets, LC3 Recruitment, and Interaction with NTPase and NS4.

Human noroviruses (HuNVs) are the leading cause of gastroenteritis worldwide. NS1.2 is critical for HuNV pathogenesis, but the function is still unclear. The GII NS1.2 of HuNVs, unlike GI NS1.2, was localized to the endoplasmic reticulum (ER) and lipid droplets (LDs) and is accompanied by a distorted-filamentous ER morphology and aggregated-enlarged LDs. LC3 was recruited to the NS1.2-localized membrane through an autophagy-independent pathway. NS1.2, expressed from a cDNA clone of GII.4 norovirus, formed complexes with NTPase and NS4, which exhibited aggregated vesicle-like structures that were also colocalized with LC3 and LDs. NS1.2 is structurally divided into three domains from the N terminus: an inherently disordered region (IDR), a region that contains a putative hydrolase with the H-box/NC catalytic center (H-box/NC), and a C-terminal 251-330 a.a. region containing membrane-targeting domain. All three functional domains of NS1.2 were required for the induction of the filamentous ER. The IDR was essential for LC3 recruitment by NS1.2. Both the H-Box/NC and membrane-targeting domains are required for the induction of aggregated-enlarged LDs, NS1.2 self-assembly, and interaction with NTPase. The membrane-targeting domain was sufficient to interact with NS4. The study characterized the NS1.2 domain required for membrane targeting and protein-protein interactions, which are crucial for forming a viral replication complex.

A new autophagy-driven protective pathway of Haematococcus astaxanthin against chemical damage in wistar rats with gentamicin-induced acute kidney injury

Astaxanthin was established to conserve kidney function and subcellular structure through anti-oxidation and/or the free radical scavenging system, yet little research linked a new protective effect to autophagy or lysosomes. We pre-fed Wistar rats with natural astaxanthin, β-carotene, or placebo and induced acute kidney injury using gentamicin, before examining renal tissues and measuring physiological indices. Qualitative evidence from histopathological and subcellular images, along with quantitative evidence showing treatment effects on blood urea nitrogen and serum creatinine (p < 0.01), indicated that esterified Haematococcus astaxanthin surpassed β-carotene at effectively counteracting chemical damage and protecting the kidneys from injury. Proliferation of enlarged lysosomes and mediation analysis results revealing enhanced lysosomal acid phosphatase activity were consistent with the hypothesized autophagy-lysosomal pathway being up-regulated by astaxanthin intake (p < 0.05). In conclusion, the protective effect of astaxanthin against acute kidney injury exerted through the autophagy-lysosomal detoxification pathway, which totally different from the anti-oxidation and/or conventional SOD-dependent free radical scavenging system, was demonstrated with strong evidence. In light of the pandemic outbreak of novel coronavirus pneumonia associated with a virus preferentially targeting the renal tubular cells, dietary astaxanthin may help bring down incidence rate of coronavirus disease, cases of acute kidney injury secondary to the disease, and mortality rate from acute kidney injury, especially when a standard of care treatment for the infectious disease is pending. © 2023 Elsevier B.V.

Glycoprotein Non-Metastatic Melanoma Protein B Restricts PRRSV Replication by Inhibiting Autophagosome-Lysosome Fusion.

Glycoprotein non-metastatic melanoma protein B (GPNMB) is a transmembrane protein enriched on the surface of some cells, including melanoma, glioblastoma, and macrophages. GPNMB has been reported to have multifaceted roles, such as facilitating cell-cell adhesion and migration, stimulating kinase signaling, and regulating inflammation. Porcine reproductive and respiratory syndrome virus (PRRSV) is the leading cause of severe economic loss in the swine industry worldwide. In this study, the role of GPNMB was investigated in porcine alveolar macrophages during PRRSV infection. We observed that GPNMB expression was markedly reduced in PRRSV-infected cells. The inhibition of GPNMB by specific small interfering RNA led to an enhancement in virus yields, and GPNMB overexpression decreased PRRSV replication. Further studies revealed that the overexpression of GPNMB could induce the accumulation of autophagosome through inhibiting autophagosome-lysosome fusion. Using a specific inhibitor, we confirmed that the inhibition of autophagosome-lysosome fusion significantly inhibited viral replication. Taken together, our data demonstrate that GPNMB inhibits PRRSV replication by inhibiting the autophagosome-lysosome fusion and provides a novel therapeutic target for virus infection.

Severe acute respiratory syndrome coronavirus-2 accessory proteins ORF3a and ORF7a modulate autophagic flux and Ca2+ homeostasis in yeast.

Virus infection involves the manipulation of key host cell functions by specialized virulence proteins. The Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) small accessory proteins ORF3a and ORF7a have been implicated in favoring virus replication and spreading by inhibiting the autophagic flux within the host cell. Here, we apply yeast models to gain insights into the physiological functions of both SARS-CoV-2 small open reading frames (ORFs). ORF3a and ORF7a can be stably overexpressed in yeast cells, producing a decrease in cellular fitness. Both proteins show a distinguishable intracellular localization. ORF3a localizes to the vacuolar membrane, whereas ORF7a targets the endoplasmic reticulum. Overexpression of ORF3a and ORF7a leads to the accumulation of Atg8 specific autophagosomes. However, the underlying mechanism is different for each viral protein as assessed by the quantification of the autophagic degradation of Atg8-GFP fusion proteins, which is inhibited by ORF3a and stimulated by ORF7a. Overexpression of both SARS-CoV-2 ORFs decreases cellular fitness upon starvation conditions, where autophagic processes become essential. These data confirm previous findings on SARS-CoV-2 ORF3a and ORF7a manipulating autophagic flux in mammalian cell models and are in agreement with a model where both small ORFs have synergistic functions in stimulating intracellular autophagosome accumulation, ORF3a by inhibiting autophagosome processing at the vacuole and ORF7a by promoting autophagosome formation at the ER. ORF3a has an additional function in Ca2+ homeostasis. The overexpression of ORF3a confers calcineurin-dependent Ca2+ tolerance and activates a Ca2+ sensitive FKS2-luciferase reporter, suggesting a possible ORF3a-mediated Ca2+ efflux from the vacuole. Taken together, we show that viral accessory proteins can be functionally investigated in yeast cells and that SARS-CoV-2 ORF3a and ORF7a proteins interfere with autophagosome formation and processing as well as with Ca2+ homeostasis from distinct cellular targets.

The role of autophagy in viral infections.

Autophagy is an evolutionarily conserved catabolic cellular process that exerts antiviral functions during a viral invasion. However, co-evolution and co-adaptation between viruses and autophagy have armed viruses with multiple strategies to subvert the autophagic machinery and counteract cellular antiviral responses. Specifically, the host cell quickly initiates the autophagy to degrade virus particles or virus components upon a viral infection, while cooperating with anti-viral interferon response to inhibit the virus replication. Degraded virus-derived antigens can be presented to T lymphocytes to orchestrate the adaptive immune response. Nevertheless, some viruses have evolved the ability to inhibit autophagy in order to evade degradation and immune responses. Others induce autophagy, but then hijack autophagosomes as a replication site, or hijack the secretion autophagy pathway to promote maturation and egress of virus particles, thereby increasing replication and transmission efficiency. Interestingly, different viruses have unique strategies to counteract different types of selective autophagy, such as exploiting autophagy to regulate organelle degradation, metabolic processes, and immune responses. In short, this review focuses on the interaction between autophagy and viruses, explaining how autophagy serves multiple roles in viral infection, with either proviral or antiviral functions.

Trend of research on the medical use of molecular hydrogen: a bibliometric analysis.

The medical use of molecular hydrogen, including hydrogen-rich water and hydrogen gas, has been extensively explored since 2007. This article aimed to demonstrate the trend in medical research on molecular hydrogen. A total of 1126 publications on hydrogen therapy were retrieved from the PubMed database until July 30, 2021. From 2007 to 2020, the number of publications in this field had been on an upward trend. Medical Gas Research, Scientific Report and Shock have contributed the largest number of publications on this topic. Researchers by the name of Xue-Jun Sun, Ke-Liang Xie and Yong-Hao Yu published the most studies in the field. Analysis of the co-occurrence of key words indicated that the key words "molecular hydrogen," "hydrogen-rich water," "oxidative stress," "hydrogen gas," and "inflammation" occurred most frequently in these articles. "Gut microbiota," "pyroptosis," and "COVID-19" occurred the most recently among the keywords. In summary, the therapeutic application of molecular hydrogen had attracted much attention in these years. The advance in this field could be caught up by subscribing to relevant journals or following experienced scholars. Oxidative stress and inflammation were the most important research directions currently, and gut microbiota, pyroptosis, and coronavirus disease 2019 might become hotspots in the future.

Introduction—Epigenetics regulations in organ specific disorders

Epigenetics is used to explain stable heritable chemical modifications to DNA and histones that affect gene expression without changing nucleotide sequence. The genetic expression of a trait in an organism can be moderated by epigenetics depending on the prevailing environmental conditions and activate different traits from the same genotype via modulating gene expression patterns. Several diseases can control or get influenced by the epigenome. A recent surge in research is focused on decoding such changes as early indicators of diseases. SARS-CoV-2, responsible for the worldwide pandemic, is also suggested to rattle the epigenetic network, impacting the host immune system negatively. While epigenetic drugs have majorly been studied in treating cancer, the increasing funding and interest have paved the way for the researchers to focus on other inflammatory diseases. The primary focus of this book has been to delineate the role of epigenetics in regulating disorders affecting organs in our body. © 2023 Elsevier Inc. All rights reserved.

Apoptosis, Autophagy, and Unfolded Protein Response and Cerebellar Development

Development is an evolutionary process that is tightly regulated in mammalian species. Several different cascades are involved in various stages of development. Among these mechanisms, apoptosis, autophagy, and unfolded protein response play critical roles in regulating development by affecting cell fate. All of these pathways are involved in the regulation of cell numbers via determining the life and death cycles of the cells. In this chapter, we first explain the brief mechanisms that are involved in the regulation of apoptosis, autophagy, and unfolded protein response, and later, we briefly describe how these mechanisms play roles in general development. We next address the critical role of these pathways in cerebellar development regulation and how they will aid in our knowledge of the processes behind neurodevelopmental disorders. Additionally, we summarize the present findings on neurological symptoms and disorders related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and their linkage to autophagy pathways in the cerebellum. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Boosting Innate Immunity During SARS-CoV-2 Clearance

Currently, humanity is suffering from a highly contagious and infectious novel coron-avirus disease. Due to the unavailability of any specifically approved therapy to eradicate this pathogenic virus, day by day, it is claiming more and more lives of humans. Observing the current scenario, human civilization seems to be in dangerous situation, and the development of a potential vaccine against this invisible enemy may take some more time. It was observed that the individual immune system plays an important role in the fight against the novel coronavirus. Additionally, the innate immune system of the host acts as the first line of defense against invading pathogenic virus-es. The host innate immune cells can detect and detoxify the evading viruses. Thus, boosting the innate immune response via targeting activator or inhibitory immune check points pathways for en-hancing T-cell immune response may potentially help the patients to fight against this deadly virus. The aim of this editorial is to discuss in brief about the pathogenesis of COVID-19, the role of innate immunity and autophagy during viral clearance.Copyright © 2021 Bentham Science Publishers.

Innate immune responses in COVID-19

Innate immunity is the first line of host defense against microbes, including SARS-CoV-2. This pleiotropic immunological mechanism is initiated within minutes to hours after infection. Here, we summarize innate immune processes involved in SARS-CoV-2 recognition, cellular, and molecular response including inflammation, as well as the related immune modulatory therapies that have been evaluated in clinical trials for COVID-19. Innate immune responses limit viral replication, help identify and remove infected cells, sense pathogen-associated molecular patterns, trigger signaling pathways, inflammatory responses, cytokine production, programmed cell death, and contribute the development of adaptive immunity. Excessive activation of the host innate immune response is associated with severe disease and death. The availability and speed of implementation of these mechanisms in infected individuals may explain in part the heterogeneous disease spectrum and courses observed in patients. © 2023 Elsevier Inc. All rights reserved.

COVID-19: honey as a potential adjuvant treatment

This article sums up the possible impact of honey in the amelioration of COVID-19 induced recognized pathogenesis. The pandemic due to the current outbreak of COVID-19 infected thousands of individuals round the globe. The indicator of COVID-19 infection suggests that increased inflammation, oxidation, and an overstressed immune reaction are key contributor of COVID-19 pathogenesis. This overstressed immune response leads to numerous cytokine production and consequently and led to the development of severe injury in lungs (ALI)/acute respiratory distress disorder and in some conditions becomes reason of death. Honey is formed when honey bees collect nectar from various, and then process it to form the honey. It is a natural remedy to reduce the incidence of various diseases, due to its potential anti-inflammatory, anti-oxidative, immune booster, antiviral, anti-diabetic, antimicrobial, anti-proliferative, cardiovascular, neurological and gastrointestinal diseases and anti-metastatic properties. Honey has been used for the curing of bronchial asthma, throat infections, tuberculosis, thirst, hiccups, fatigue, and hepatitis and also for the ALI/ARDS treatment caused by virus or any other pathogen. Doctors recommend honey as a nutritional supplement to boost the immunity of patients under critical conditions, reducing oxidative stress, inflammation, viral infections that confirm that honey may be used to combat the infection and other complications caused by COVID-19 pandemic. There are many reports which reveal that honey may be used in bacterial and viral infections such as COVID-19, however, further experimental studies are required to validate these speculations.

Neutrophil autophagy and NETosis in COVID-19: perspectives.

The COVID-19 pandemic has caused substantial losses worldwide in people's lives, health, and property. Currently, COVID-19 is still prominent worldwide without any specific drug treatment. The SARS-CoV-2 pathogen is the cause of various systemic diseases, mainly acute pneumonia. Within the pathological process, neutrophils are recruited to infected sites, especially in the lungs, for the first stage of removing invading SARS-CoV-2 through a range of mechanisms. Macroautophagy/autophagy, a conserved autodegradation process in neutrophils, plays a crucial role in the neutrophil phagocytosis of pathogens. NETosis refers to neutrophil cell death, while auto-inflammatory factors and antigens release NETs. This review summarizes the latest research progress and provides an in-depth explanation of the underlying mechanisms of autophagy and NETosis in COVID-19. Furthermore, after exploring the relationship between autophagy and NETosis, we discuss potential targets and treatment options. This review keeps up with the latest research on COVID-19 from neutrophil autophagy and NETosis with a new perspective, which can guide the urgent development of antiviral drugs and provide guidance for the clinical treatment of COVID-19.Abbreviations: AKT1: AKT serine/threonine kinase 1; AMPK: AMP-activated protein kinase; AP: autophagosome; ARDS: acute respiratory distress syndrome; ATG: autophagy related; BECN1: beclin 1; cfDNA: cell-free DNA; COVID-19: coronavirus disease 2019; CQ: chloroquine; DMVs: double-membrane vesicles; ELANE/NE: elastase, neutrophil expressed; F3: coagulation factor III, tissue factor; HCQ: hydroxychloroquine; MAP1LC3/LC3: microtubule associated protein 1 light chain of 3; MPO: myeloperoxidase; MTORC1: mechanistic target of rapamycin kinase complex 1; NETs: neutrophil traps; NSP: nonstructural protein; PI3K: class I phosphoinositide 3-kinase; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; ROS: reactive oxygen species; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; SKP2: S-phase kinase associated protein 2; TCC: terminal complement complex; ULK1: unc-51 like.