Perspective on Adenoviruses: Epidemiology, Pathogenicity, and Gene Therapy

A Comprehensive Review of Adenoviral Conjunctivitis: Exploring the Role of Povidone-iodine in Treatment

This review highlights recent developments in the management of adenoviral conjunctivitis (AC), the most common cause of viral conjunctivitis, which can lead to serious complications like subepithelial infiltrates, pseudomembrane formation, and conjunctival scarring. This paper discusses the pathogenic serotypes, particularly those responsible for epidemic keratoconjunctivitis (EKC), and new treatment options, with a focus on povidone-iodine (PVP-I). Diagnosis of AC is primarily based on clinical evaluation, although laboratory testing and imaging may support the assessment. Recent investigation suggests that PVP-I is a promising treatment option, as it can reduce viral load and alleviate symptoms, with minimal adverse effects. However, further research is needed to refine the optimal treatment protocols for PVP-I.

Removal capacities of wastewater treatment plants to minimize spread of enteroviruses

The enteroviruses such as Adenovirus, Enterovirus, Hepatitis A virus, Norovirus, and Rotavirus are mostly transmitted via water and are commonly seen in Turkey. Due to lack of regulations for monitoring these viruses at the discharge points of wastewater treatment plants (WWTPs), the discharges reach to surface waters causing water-borne diseases. This emphasizes the importance of WWTPs' removal capacities to minimize the spread of enteroviruses. To evaluate the removal capacities of enteroviruses, five different types of WWTPs from Ankara-Turkey were investigated over a year. Seasonal abundances of enterovirus-specific genes in both influents and effluents from each WWTP were determined by quantitative polymerase chain reaction (qPCR). The reduction of enteroviral nucleic acids in the effluent wastewater samples compared to the influent wastewater samples was assessed as the removal capacity in log10 reduction values (LRVs). The qPCR results revealed that among five different types of WWTPs tested, membrane bioreactors effectively removed Adenovirus alone with LRVs more than 3. The removal of Enterovirus, Hepatitis A virus, Norovirus, and Rotavirus in WWTPs with varying processes was below LRV 3.

Immunological pathogenesis and treatment progress of adenovirus pneumonia in children

Human adenovirus is an infectious agent that causes respiratory infections in adults and children. It has been found that immunocompromised children are highly susceptible to this pathogen, as it can swiftly evolve into severe pneumonia with multiple sequelae. Due to the lack of immunity in children, the body's response mechanisms to innate and acquired immunity are specialized. We first examined the infection classification and clinical characteristics associated with adenovirus in children. Subsequently, we explored the in-depth understanding of the pathogenic mechanism of adenovirus pneumonia in children, focusing on immunological and cellular biological aspects. Adenovirus infection in children can disrupt the balance of the innate immune response, inducing immune cells to secrete an abundance of pro-inflammatory cytokines. This cascade results in a cytokine storm, which triggers an inflammatory response and causes lung tissue damage. As a result, the infection may progress to a severe state, potentially leading to multi-organ failure. Immunocompromised children exhibit impaired immune cell numbers and functions, which affects both the secretion of antibodies to humoral immunity and the immune response of cellular immunity to adenovirus. Lastly, we reviewed the progress in treating adenovirus pneumonia in children. There are many treatments for adenovirus pneumonia in children, which must be personalized based on a thorough assessment to optimize treatment outcomes. Recent advancements in pharmaceutical development have provided new treatment options for children. Immunomodulatory therapy can reduce inflammation in children, while adjuvant therapy can improve respiratory function; however, it can also lead to complications. Further, co-infections increased the complexity of diagnosis and treatment, necessitating dynamic adjustments to treatment regimens. This review could serve as the basis for identifying potential therapeutic approaches to alleviate the symptoms associated with adenovirus infections in children.

αFAP-specific nanobodies mediate a highly precise retargeting of modified AAV2 capsids thereby enabling specific transduction of tumor tissues

Due to the refractiveness of tumor tissues to adeno-associated virus (AAV) transduction, AAV vectors are poorly explored for cancer therapy delivery. Here, we aimed to engineer AAVs to target tumors by enabling the specific engagement of fibroblast activation protein (FAP). FAP is a cell surface receptor distinctly upregulated in the reactive tumor stroma, but rarely expressed in healthy tissues. Thus, targeting FAP presents an opportunity to selectively transduce tumor tissues. To achieve this, we modified the capsid surface of AAV2 with an αFAP nanobody to retarget the capsid to engage FAP receptor. Following transduction, we observed a 23- to 80-fold increase in the selective transduction of FAP+ tumor cells in vitro, and greater than 5-fold transduction of FAP+ tumor tissues in vivo. Subsequent optimization of the VP1-nanobody expression cassette further enhanced the transduction efficiency of the modified capsids. Due to the limited αFAP nanobodies repertoires, we broadened the versatility of this high-fidelity platform by screening a naive VHH yeast display library, leading to the identification of several novel αFAP nanobody candidates (KD = 0.1 to >100 nM). Hence, our study offers new opportunity for the application of AAV vectors for highly selective delivery of therapeutics to the tumor stroma.

Mutated Adenovirus Attacks in West Bengal, India: Risk Evaluation of Multi-Country Outbreaks and Mitigation Strategies

AIM

The human adenovirus (HAdV) is beginning to spread rapidly in children through human, surface and animal vectors. Around 12,000 cases were recognised in 2022 in West Bengal and a shocking number of cases arose throughout India and in other under-developed areas. This is going to be a big threat to public health since no vaccine, awareness or protocol policies were introduced. Early detection, immediate isolation and proper policy developments are the key factors in overcoming the situation. Therefore, we performed this rapid review and discussed probable mitigation strategies, updated research on vaccine development, and treatment strategies to control the outbreaks of mutated HAdV.

DESIGN

This is a narrative review of publicly available information.

METHODS

Here, we extracted updated information and data using the terms HAdV outbreaks, mutations, species, risks and prevention from Google Scholar and PubMed. We considered relevant articles that have discussed prevention strategies, ongoing research, and antiviral drugs for managing HAdV outbreaks.

RESULTS

Early detection from throat swabs, isolation and symptomatic treatments are required to minimise viral infections. A massive test needs to be performed to find the affected people. The cases should be immediately isolated. It is recommended to treat high-touch surfaces with heat- or bleach-containing cleaners to prevent the spread of infection. Oxygen support and many broad-spectrum antivirals have been used to treat HAdV. Several studies showed antibody neutralisation and interactions between the natural killer cell receptor KIR3DS1 and HLA-F in infected cells, indicating possible therapeutic options in the future. HAdV-4 and HAdV-7 vaccines have been limitedly approved for administration to military personnel.

CONCLUSION

Isolation, certain safety measures, broad-spectrum antiviral drugs and further research on new vaccines could be useful to prevent this virus from producing a worldwide pandemic. Also, the authorities should ensure the proper therapeutic interventions and nursing care facilities for the infected children.

PATIENT OR PUBLIC CONTRIBUTION

Patient or public contribution was not relevant to our work.

Nanogene editing drug delivery systems in the treatment of liver fibrosis

Liver fibrosis is a group of diseases that seriously affect the health of the world's population. Despite significant progress in understanding the mechanisms of liver fibrogenesis, the technologies and drugs used to treat liver fibrosis have limited efficacy. As a revolutionary genetic tool, gene editing technology brings new hope for treating liver fibrosis. Combining nano-delivery systems with gene editing tools to achieve precise delivery and efficient expression of gene editing tools that can be used to treat liver fibrosis has become a rapidly developing field. This review provides a comprehensive overview of the principles and methods of gene editing technology and commonly used gene editing targets for liver fibrosis. We also discuss recent advances in common gene editing delivery vehicles and nano-delivery formulations in liver fibrosis research. Although gene editing technology has potential advantages in liver fibrosis, it still faces some challenges regarding delivery efficiency, specificity, and safety. Future studies need to address these issues further to explore the potential and application of liver fibrosis technologies in treating liver fibrosis.

Molecular insights into type I interferon suppression and enhanced pathogenicity by species B human adenoviruses B7 and B14

Human adenoviruses (HAdVs) are small DNA viruses that generally cause mild disease. Certain strains, particularly those belonging to species B HAdVs, can cause severe pneumonia and have a relatively high mortality rate. Little is known about the molecular aspects of how these highly pathogenic species affect the infected cell and how they suppress innate immunity. The present study provides molecular insights into how species B adenoviruses suppress the interferon signaling pathway. Our study shows that these viruses, unlike HAdV-C2, are resistant to type I interferon. This resistance likely arises due to the highly efficient suppression of interferon-stimulated gene expression. Unlike in HAdV-C2, HAdV-B7 and B14 sequester STAT2 and RNA polymerase II from interferon-stimulated gene promoters in infected cells. This results in suppressed interferon- stimulated gene activation. In addition, we show that RuvBL1 and RuvBL2, cofactors important for RNA polymerase II recruitment to promoters and interferon-stimulated gene activation, are redirected to the cytoplasm forming high molecular weight complexes that, likely, are unable to associate with chromatin. Proteomic analysis also identified key differences in the way these viruses affect the host cell, providing insights into species B-associated high pathogenicity. Curiously, we observed that at the level of protein expression changes to the infected cell, HAdV-C2 and B7 were more similar than those of the same species, B7 and B14. Collectively, our study represents the first such study of innate immune suppression by the highly pathogenic HAdV-B7 and B14, laying an important foundation for future investigations.IMPORTANCEHuman adenoviruses form a large family of double-stranded DNA viruses known for a variety of usually mild diseases. Certain strains of human adenovirus cause severe pneumonia leading to much higher mortality and morbidity than most other strains. The reasons for this enhanced pathogenicity are unknown. Our study provides a molecular investigation of how these highly pathogenic strains might inactivate the interferon signaling pathway, highlighting the lack of sensitivity of these viruses to type I interferon in general while providing a global picture of how viral changes in cellular proteins drive worse disease outcomes.

Inhibition of B cell receptor signaling induced by the human adenovirus species D E3/49K protein

Introduction

The early transcription unit 3 (E3) of human adenoviruses (HAdVs) encodes several immunoevasins, including the E3/49K protein, which is unique for species D of HAdVs. It is expressed as surface transmembrane protein and shed. E3/49K of HAdV-D64 binds to the protein tyrosine phosphatase surface receptor CD45, thereby modulating activation of T and NK cells.

Methods

Considering that E3/49K represents the most polymorphic viral protein among species D HAdVs, we demonstrate here that all tested E3/49K orthologs bind to the immunologically important regulator CD45. Thus, this feature is conserved regardless of the pathological associations of the respective HAdV types.

Results

It appeared that modulation of CD45 is a unique property restricted to HAdVs of species D. Moreover, E3/49K treatment inhibited B cell receptor (BCR) signaling and impaired BCR signal phenotypes. The latter were highly comparable to B cells having defects in the expression of CD45, suggesting E3/49K as a potential tool to investigate CD45 specific functions.

Conclusion

We identified B cells as new direct target of E3/49K-mediated immune modulation, representing a novel viral immunosubversive mechanism.

Breaking the Chain: Protease Inhibitors as Game Changers in Respiratory Viruses Management

Respiratory viral infections (VRTIs) rank among the leading causes of global morbidity and mortality, affecting millions of individuals each year across all age groups. These infections are caused by various pathogens, including rhinoviruses (RVs), adenoviruses (AdVs), and coronaviruses (CoVs), which are particularly prevalent during colder seasons. Although many VRTIs are self-limiting, their frequent recurrence and potential for severe health complications highlight the critical need for effective therapeutic strategies. Viral proteases are crucial for the maturation and replication of viruses, making them promising therapeutic targets. This review explores the pivotal role of viral proteases in the lifecycle of respiratory viruses and the development of protease inhibitors as a strategic response to these infections. Recent advances in antiviral therapy have highlighted the effectiveness of protease inhibitors in curtailing the spread and severity of viral diseases, especially during the ongoing COVID-19 pandemic. It also assesses the current efforts aimed at identifying and developing inhibitors targeting key proteases from major respiratory viruses, including human RVs, AdVs, and (severe acute respiratory syndrome coronavirus-2) SARS-CoV-2. Despite the recent identification of SARS-CoV-2, within the last five years, the scientific community has devoted considerable time and resources to investigate existing drugs and develop new inhibitors targeting the virus's main protease. However, research efforts in identifying inhibitors of the proteases of RVs and AdVs are limited. Therefore, herein, it is proposed to utilize this knowledge to develop new inhibitors for the proteases of other viruses affecting the respiratory tract or to develop dual inhibitors. Finally, by detailing the mechanisms of action and therapeutic potentials of these inhibitors, this review aims to demonstrate their significant role in transforming the management of respiratory viral diseases and to offer insights into future research directions.

Acute Hepatitis of Unknown Origin in Children: Analysis of 17 Cases Admitted to the Bambino Gesù Children's Hospital in Rome

This study described 17 cases of children admitted to the Bambino Gesù Children's Hospital with acute hepatitis of unknown origin between mid-April and November 2022. Following the World Health Organization's working case definition of probable cases, 17 children, with a median age of 2.1 years (interquartile range: 1.0-7.1), presenting with acute hepatitis non-AE, with serum transaminase >500 IU/L, were included in the study. A pre-specified set of microbiological tests was performed on different biological specimens for all pediatric patients. All patients resulted negative for the common hepatotropic viruses. The most common pathogen detected in blood specimens was human-herpes-virus-7 (52.9%). Adenovirus was detected more frequently in stool specimens (62.5%) than in respiratory (20.0%) or blood samples (17.6%). Regarding Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, one child tested positive two days after admission, while antibodies against spike and nucleoprotein were present in 82.3% of patients. A co-pathogen detection was observed in 94.1% of children. Overall, 16 children recovered without clinical complications, while one patient required liver transplantation. In these cases of acute hepatitis of unknown origin, adenovirus was mainly detected in stool samples. A co-pathogen detection was also frequently observed, suggesting that the etiology of this acute hepatitis is most probably multifactorial.

Advances of Recombinant Adenoviral Vectors in Preclinical and Clinical Applications

Adenoviruses (Ad) have the potential to induce severe infections in vulnerable patient groups. Therefore, understanding Ad biology and antiviral processes is important to comprehend the signaling cascades during an infection and to initiate appropriate diagnostic and therapeutic interventions. In addition, Ad vector-based vaccines have revealed significant potential in generating robust immune protection and recombinant Ad vectors facilitate efficient gene transfer to treat genetic diseases and are used as oncolytic viruses to treat cancer. Continuous improvements in gene delivery capacity, coupled with advancements in production methods, have enabled widespread application in cancer therapy, vaccine development, and gene therapy on a large scale. This review provides a comprehensive overview of the virus biology, and several aspects of recombinant Ad vectors, as well as the development of Ad vector, are discussed. Moreover, we focus on those Ads that were used in preclinical and clinical applications including regenerative medicine, vaccine development, genome engineering, treatment of genetic diseases, and virotherapy in tumor treatment.

Human adenovirus type 3 restores pharmacologically inhibited exosomal cargo in lung carcinoma cells

Introduction: Drug repurposing is fast growing and becoming an attractive approach for identifying novel targets, such as exosomes for cancer and antiviral therapy. Exosomes are a specialized class of extracellular vesicles that serve as functional mediators in intercellular communication and signaling that are important in normal physiological functions. A continuously growing body of evidence has established a correlation between the abnormal release of exosomes with various viral disease pathologies including cancer. Cells that are virus-infected release exosomes known to influence the process via the loading and transfer of viral components, such as miRNA, small (s) RNA, DNA, and proteins. Inhibition of exosome release may abate the spread and severity of viral infection, thus making exosomes an attractive target for antiviral therapies. We previously demonstrated the pharmacological inhibition of exosomes. Methods: Herein, we used a cell-based assay to determine the effect of Human adenovirus type 3 (HAdV3) on the exosome inhibition process by azole and Heparin derivatives. HAdV3-infected cells were treated with two concentrations of each inhibitor at different time points. Results: HAdV3 activities led to increased total sRNA, DNA, and exosome particle concentrations via particle tracking in the presence of Climbazole and Heparin relative to uninfected exosomes. In addition, there was an increased expression of classical markers such as ALG-2 interacting protein X (ALIX), and tetraspanin (CD63), (p < 0.05) and upregulated transcription factor interferon regulatory factor (IRF) 8 in the presence of HAdV3 after 24 hours (h) of treatment. Whereas higher concentrations of Climbazole and Heparin sodium salt were found to inhibit total exosome protein (p < 0.001) and exo-RNA (p < 0.01) content even in the presence of HAdV3 relative to infected exosomes only. Activities of HAdV3 in the presence of selected inhibitors resulted in the positive regulation of exosome related DNA damage/repair signaling proteins. Blocking exosome secretion partially obstructed viral entry. Immunological studies revealed that HAdV3 fiber protein levels in A549 cells were reduced at all concentrations of Climbazole and Heparin and both multiplicities of infections (p < 0.001). Discussion: Our findings suggest that while HAdV may bolster inhibited exosome content and release when modulating certain activities of the endosomal pathway mediators, HAdV entry might be constrained by the activities of these pharmacological agents.

In Vitro Models for Investigating Intestinal Host-Pathogen Interactions

Infectious diseases are increasingly recognized as a major threat worldwide due to the rise of antimicrobial resistance and the emergence of novel pathogens. In vitro models that can adequately mimic in vivo gastrointestinal physiology are in high demand to elucidate mechanisms behind pathogen infectivity, and to aid the design of effective preventive and therapeutic interventions. There exists a trade-off between simple and high throughput models and those that are more complex and physiologically relevant. The complexity of the model used shall be guided by the biological question to be addressed. This review provides an overview of the structure and function of the intestine and the models that are developed to emulate this. Conventional models are discussed in addition to emerging models which employ engineering principles to equip them with necessary advanced monitoring capabilities for intestinal host-pathogen interrogation. Limitations of current models and future perspectives on the field are presented.

Extracellular Vesicles: A Novel Mode of Viral Propagation Exploited by Enveloped and Non-Enveloped Viruses

Extracellular vesicles (EVs) are small membrane-enclosed structures that have gained much attention from researchers across varying scientific fields in the past few decades. Cells secrete diverse types of EVs into the extracellular milieu which include exosomes, microvesicles, and apoptotic bodies. These EVs play a crucial role in facilitating intracellular communication via the transport of proteins, lipids, DNA, rRNA, and miRNAs. It is well known that a number of viruses hijack several cellular pathways involved in EV biogenesis to aid in their replication, assembly, and egress. On the other hand, EVs can also trigger host antiviral immune responses by carrying immunomodulatory molecules and viral antigens on their surface. Owing to this intricate relationship between EVs and viruses, intriguing studies have identified various EV-mediated viral infections and interrogated how EVs can alter overall viral spread and longevity. This review provides a comprehensive overview on the EV-virus relationship, and details various modes of EV-mediated viral spread in the context of clinically relevant enveloped and non-enveloped viruses.

Common and Potential Emerging Foodborne Viruses: A Comprehensive Review

Human viruses and viruses from animals can cause illnesses in humans after the consumption of contaminated food or water. Contamination may occur during preparation by infected food handlers, during food production because of unsuitably controlled working conditions, or following the consumption of animal-based foods contaminated by a zoonotic virus. This review discussed the recent information available on the general and clinical characteristics of viruses, viral foodborne outbreaks and control strategies to prevent the viral contamination of food products and water. Viruses are responsible for the greatest number of illnesses from outbreaks caused by food, and risk assessment experts regard them as a high food safety priority. This concern is well founded, since a significant increase in viral foodborne outbreaks has occurred over the past 20 years. Norovirus, hepatitis A and E viruses, rotavirus, astrovirus, adenovirus, and sapovirus are the major common viruses associated with water or foodborne illness outbreaks. It is also suspected that many human viruses including Aichi virus, Nipah virus, tick-borne encephalitis virus, H5N1 avian influenza viruses, and coronaviruses (SARS-CoV-1, SARS-CoV-2 and MERS-CoV) also have the potential to be transmitted via food products. It is evident that the adoption of strict hygienic food processing measures from farm to table is required to prevent viruses from contaminating our food.

Genomic Expedition: Deciphering Human Adenovirus Strains from the 2023 Outbreak in West Bengal, India: Insights into Viral Evolution and Molecular Epidemiology

Understanding the genetic dynamics of circulating Human Adenovirus (HAdV) types is pivotal for effectively managing outbreaks and devising targeted interventions. During the West Bengal outbreak of 2022-2023, an investigation into the genetic characteristics and outbreak potential of circulating HAdV types was conducted. Twenty-four randomly selected samples underwent whole-genome sequencing. Analysis revealed a prevalent recombinant strain, merging type 3 and type 7 of human mastadenovirus B1 (HAd-B1) species, indicating the emergence of recent strains of species B in India. Furthermore, distinctions in VA-RNAs and the E3 region suggested that current circulating strains of human mastadenovirus B1 (HAd-B1) possess the capacity to evade host immunity, endure longer within hosts, and cause severe respiratory infections. This study underscores the significance of evaluating the complete genome sequence of HAdV isolates to glean insights into their outbreak potential and the severity of associated illnesses.

Construction and application of adenoviral vectors

Adenoviral vectors have been widely used as vaccine candidates or potential vaccine candidates against infectious diseases due to the convenience of genome manipulation, their ability to accommodate large exogenous gene fragments, easy access of obtaining high-titer of virus, and high efficiency of transduction. At the same time, adenoviral vectors have also been used extensively in clinical research for cancer gene therapy and treatment of diseases caused by a single gene defect. However, application of adenovirus also faces a series of challenges such as poor targeting, strong immune response against the vector itself, and they cannot be used repeatedly. It is believed that these problems will be solved gradually with further research and technological development in related fields. Here, we review the construction methods of adenoviral vectors, including "gutless" adenovirus and discuss application of adenoviral vectors as prophylactic vaccines for infectious pathogens and their application prospects as therapeutic vaccines for cancer and other kinds of chronic infectious disease such as human papillomavirus, hepatitis B virus, and hepatitis C virus.

Seroprevalence of human adenovirus type 5 neutralizing antibodies in the Philippines

Human adenovirus (HAdV), particularly the HAdV type 5 (HAdV-5), has been extensively utilized in the development of vector vaccines due to its high immunogenicity, good safety profile, and ease of propagation. However, one of the main challenges in its use is the presence of pre-existing immunity among vaccine recipients. Pre-existing neutralizing antibodies (NAbs) can prevent the uptake of HAdV-5 vectors and reduce vaccine efficacy. Hence, this study investigated the seroprevalence of NAbs against HAdV-5 in urban and rural regions of the Philippines. Luciferase-based neutralization assay was performed on 391 plasma/serum samples. Out of these samples, 346 or 88.5% were positive for HAdV-5 NAbs, and the majority of them (56.8%) had high titers against the virus. Among the regions included in this study, Bicol (Region V) had the highest seroprevalence rate (94.1%). Our findings show that a significant number of adults in the Philippines have pre-existing immunity against HAdV-5. This supports the recommendation that vaccination programs in the country should consider implementing vaccination techniques, such as a prime-boost regimen or addition of booster doses, to address the potential negative effects of pre-existing HAdV-5 immunity in the efficacy of adenoviral vector-based vaccines.

Innate Immune Response to Viral Vectors in Gene Therapy

Viral vectors play a pivotal role in the field of gene therapy, with several related drugs having already gained clinical approval from the EMA and FDA. However, numerous viral gene therapy vectors are currently undergoing pre-clinical research or participating in clinical trials. Despite advancements, the innate response remains a significant barrier impeding the clinical development of viral gene therapy. The innate immune response to viral gene therapy vectors and transgenes is still an important reason hindering its clinical development. Extensive studies have demonstrated that different DNA and RNA sensors can detect adenoviruses, adeno-associated viruses, and lentiviruses, thereby activating various innate immune pathways such as Toll-like receptor (TLR), cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING), and retinoic acid-inducible gene I-mitochondrial antiviral signaling protein (RLR-MAVS). This review focuses on elucidating the mechanisms underlying the innate immune response induced by three widely utilized viral vectors: adenovirus, adeno-associated virus, and lentivirus, as well as the strategies employed to circumvent innate immunity.

Selective pharmacological inhibition alters human carcinoma lung cell-derived extracellular vesicle formation

Exosomes also termed small extracellular vesicles (sEVs) are important mediators of intercellular communication in many physiological and pathological processes such as protein clearance, immunity, infections, signaling, and cancer. Elevated circulating levels of exosomes have been linked to some viral infections, aggressive cancer, and neurodegenerative diseases. Some pharmacological compounds have been demonstrated to effectively inhibit exosome production pathways. There are very few studies on exosome inhibition and how they influence pathophysiological conditions.

Methods

In the current study, we examined how inhibition of extracellular vesicle release and/or uptake would impact the exosome formation pathway. Using a constellation of improved EV experimental approaches, we evaluated the concentration-based cytotoxicity effects of pharmacological agents (ketoconazole, climbazole, and heparin) on Human Lung Carcinoma (A549) cell viability. We investigated the effect of inhibitor dosages on exosome production and release. Analysis of exosome inhibition includes quantitative analysis and total protein expression of exosome release after pharmacological inhibition; we examined exosome protein level after inhibition.

Results

Selective inhibition of exosomes altered particle sizes, and heparin significantly reduced the total exosomes released. Climbazole and heparin undermined membrane-bound tetraspanin CD63 expression and significantly disrupted ALIX protein (p ≤ 0.0001) and TSG101 (p ≤ 0.001). Azoles and heparin also disrupt transmembrane trafficking by modulating Ras binding protein (p ≤ 0.001).

Conclusion

These findings revealed that pharmacological inhibition of exosomes regulates the endocytic pathway and expression of endosomal sorting complex required for transport mediators, suggesting climbazole and heparin as effective inhibitors of exosome synthesis.

Progress, and prospects in the therapeutic armamentarium of persons with congenital hemophilia. Defining the place for liver-directed gene therapy

In persons with congenital severe hemophilia A (HA) living in high-income countries, twice weekly intravenous infusions of extended half-life (EHL) factor VIII (FVIII) products, or weekly/biweekly/monthly subcutaneous injections of emicizumab are the gold standard home treatments to grant days without hurdles and limitations. Once weekly/twice monthly infusions of EHL Factor IX (FIX) products achieve the same target in severe hemophilia B (HB). Gene therapy, which is likely to be licensed for clinical use within 1-2 years, embodies a shift beyond these standards. At an individual patient level, a single functional gene transfer leads to a > 10-yr almost full correction of the hemostatic defect in HB and to a sustained (3-6-yrs) expression of FVIII sufficient to discontinue exogenous clotting factor administrations. At the doses employed, the limited liver toxicity of systemically infused recombinant adeno-associated virus (rAAV) vectors is documented by long-term (12-15 yrs) follow-ups, and pre-existing high-titer neutralizing antibodies to the AAV5 vector are no longer an exclusion criterion for effective transgene expression with this vector. A safe durable treatment that converts a challenging illness to a phenotypically curable disease, allows persons to feel virtually free from the fears and the obligations of hemophilia for years/decades. Along with patient organizations and health care professionals, communicating to government authorities and reimbursement agencies the liberating potential of this substantial innovation, and disseminating across the Centers updated information on benefits and risks of this strategy, will align expectations of different stakeholders and establish the notion of a potentially lifelong cure of hemophilia.

An Old Acquaintance: Could Adenoviruses Be Our Next Pandemic Threat?

Human adenoviruses (HAdV) are one of the most important pathogens detected in acute respiratory diseases in pediatrics and immunocompromised patients. In 1953, Wallace Rowe described it for the first time in oropharyngeal lymphatic tissue. To date, more than 110 types of HAdV have been described, with different cellular tropisms. They can cause respiratory and gastrointestinal symptoms, even urinary tract inflammation, although most infections are asymptomatic. However, there is a population at risk that can develop serious and even lethal conditions. These viruses have a double-stranded DNA genome, 25-48 kbp, 90 nm in diameter, without a mantle, are stable in the environment, and resistant to fat-soluble detergents. Currently the diagnosis is made with lateral flow immunochromatography or molecular biology through a polymerase chain reaction. This review aimed to highlight the HAdV variability and the pandemic potential that a HAdV3 and 7 recombinant could have considering the aggressive outbreaks produced in health facilities. Herein, we described the characteristics of HAdV, from the infection to treatment, vaccine development, and the evaluation of the social determinants of health associated with HAdV, suggesting the necessary measures for future sanitary control to prevent disasters such as the SARS-CoV-2 pandemic, with an emphasis on the use of recombinant AdV vaccines to control other potential pandemics.

Outbreak of acute respiratory disease caused by human adenovirus type 7 and human coronavirus-229E in Zhejiang Province, China

In 2019, an outbreak of pharyngoconjunctival fever (PCF) occurred at a swimming center in Zhejiang Province, China. A total of 97 (13.55%) of the 716 amateur swimmers had illnesses, with 24 patients (24.74%) hospitalized in the pediatric ward. Human adenovirus serotype 7 (HAdV-7) was isolated from one concentrated water from the swimming pool, and 20 of 97 positive cases without liver damage. This outbreak led to a nosocomial outbreak in the pediatric ward, in which 1 nurse had a fever and was confirmed to be adenovirus positive. The hexon, fiber, and penton genes from 20 outbreak cases, 1 water sample, and 1 nurse had 100% homology. Furthermore, 2 cases admitted to the pediatric ward, 2 parents, and 1 doctor were confirmed to be human coronaviruses (HCoV-229E) positive. Finally, all outbreak cases had fully recovered, regardless of a single infection (adenovirus or HCoV-229E) or coinfection of these two viruses simultaneously. Thus, PCF and acute respiratory disease outbreaks in Zhejiang were caused by the completely homologous type 7 adenovirus and HCoV-229E, respectively. The swimming pool water contaminated with HAdV-7 was most likely the source of the PCF outbreak, whereas nosocomial transmission might be the source of HCoV-229E outbreak.

COVID-19, Influenza, and Other Acute Respiratory Viral Infections: Etiology, Immunopathogenesis, Diagnosis, and Treatment. Part 2. Other Acute Respiratory Viral Infections

The first part of this paper presented the current knowledge on two very significant respiratory diseases with high pandemic potential, COVID-19 and influenza. The second part reviews other pathogens that cause acute respiratory viral infections, ARVI, including parainfluenza viruses, adenoviruses, pneumoviruses and specifically respiratory syncytial virus, enteroviruses, rhinoviruses, bocaviruses, and seasonal coronaviruses. The review presents modern data on the structure and replication of viruses, epidemiology and immunopathogenesis of diseases, diagnostics, preventive vaccination, and antiviral drugs. Topical issues regarding ARVI vaccination and the search for new broad-spectrum antiviral drugs are discussed.

Mastadenovirus Molecular Diversity in Waste and Environmental Waters from the Lisbon Metropolitan Area

In face of the absence of epidemiological data regarding the circulation of human adenoviruses (HAdV) in Portugal, this study aimed at the evaluation of their molecular diversity in waste and environmental waters in the Lisbon Metropolitan Area (LMA). Using samples collected between 2018 and 2021, the HAdV hexon protein-coding sequence was partially amplified using three nested touch-down PCR protocols. The amplification products obtained were analyzed in parallel by two approaches: molecular cloning followed by Sanger sequencing and Next-Generation Sequencing (NGS) using Illumina^® sequencing. The analysis of NGS-generated data allowed the identification of a higher diversity of HAdV-A (19%), -B (1%), -C (3%), -D (24%), and -F (25%) viral types, along with murine adenovirus (MAdV-2; 30%) in the wastewater treatment plant samples. On the other hand, HAdV-A (19%), -D (32%), and -F (36%) were identified in environmental samples, and possibly MAdV-2 (14%). These results demonstrate the presence of fecal contamination in environmental waters and the assessment of the diversity of this virus provides important information regarding the distribution of HAdV in LMA, including the detection of HAdV-F41, the most frequently reported in water worldwide.

Significance of Preexisting Vector Immunity and Activation of Innate Responses for Adenoviral Vector-Based Therapy

An adenoviral (AdV)-based vector system is a promising platform for vaccine development and gene therapy applications. Administration of an AdV vector elicits robust innate immunity, leading to the development of humoral and cellular immune responses against the vector and the transgene antigen, if applicable. The use of high doses (10¹¹-10¹³ virus particles) of an AdV vector, especially for gene therapy applications, could lead to vector toxicity due to excessive levels of innate immune responses, vector interactions with blood factors, or high levels of vector transduction in the liver and spleen. Additionally, the high prevalence of AdV infections in humans or the first inoculation with the AdV vector result in the development of vector-specific immune responses, popularly known as preexisting vector immunity. It significantly reduces the vector efficiency following the use of an AdV vector that is prone to preexisting vector immunity. Several approaches have been developed to overcome this problem. The utilization of rare human AdV types or nonhuman AdVs is the primary strategy to evade preexisting vector immunity. The use of heterologous viral vectors, capsid modification, and vector encapsulation are alternative methods to evade vector immunity. The vectors can be optimized for clinical applications with comprehensive knowledge of AdV vector immunity, toxicity, and circumvention strategies.

Risk Factors for the Development of Post-Infectious Bronchiolitis Obliterans in Children: A Systematic Review and Meta-Analysis

Post-infectious bronchiolitis obliterans (PIBO), one of the major complications of respiratory tract infection, is commonly underdiagnosed. To identify the risk groups that may develop PIBO and avoid misdiagnoses, we investigated the risk factors associated with the development of PIBO. We searched PubMed, Embase, and MEDLINE databases for studies that included risk factors for the development of PIBO published from inception to 13 June 2022. We limited our search to studies that reported the estimates of odds ratio (OR), hazard ratio (HR), or relative risks for developing PIBO. A fixed-effect and a random-effect model were used. We included seven studies reporting data on the risk factors for PIBO in 344 children with PIBO and 1310 control children. Twenty-two variables, including sex, age, respiratory pathogens, symptoms, laboratory and radiologic findings, and mechanical ventilation, were mentioned in at least one study. The significant risk factors mentioned in two or more studies included elevated lactate dehydrogenase levels, pleural effusion, hypoxemia, sex, and mechanical ventilation. The significance of the duration of hospitalization and fever as risk factors for PIBO differed when the studies were classified according to the statistical method. In addition, the risk factors differed according to respiratory infection pathogens. This meta-analysis identified potential risk factors associated with the development of PIBO. The results of this study highlight the importance of avoiding misdiagnosis and help establish management strategies for patients at a high risk of developing PIBO.

β-cyclodextrin based nano gene delivery using pharmaceutical applications to treat Wolfram syndrome

Wolfram syndrome is a rare multisystem autosomal recessive neurodegenerative disorder that affects the brain and central nervous system. Currently, there is no cure or treatment for Wolfram syndrome. Therefore, new techniques are needed to target the loss of the WFS1 gene. Gene therapy approach to introduce a functional gene using a viral or a non-viral vector could be a treatment strategy for Wolfram syndrome 1 (WS1). Viral vectors have therapeutic benefits and greater efficiency; however, they pose a high health risk. Recently pharmaceutical therapeutic research has developed cell-penetrating non-viral nano molecules that could be used as vectors for gene delivery. Among nonviral vectors, the unique properties of β-cyclodextrin suggest that it can be a promising safe vector for gene delivery.

Global public health implications of human exposure to viral contaminated water

Enteric viruses are common waterborne pathogens found in environmental water bodies contaminated with either raw or partially treated sewage discharge. Examples of these viruses include adenovirus, rotavirus, noroviruses, and other caliciviruses and enteroviruses like coxsackievirus and polioviruses. They have been linked with gastroenteritis, while some enteric viruses have also been implicated in more severe infections such as encephalitis, meningitis, hepatitis (hepatitis A and E viruses), cancer (polyomavirus), and myocarditis (enteroviruses). Therefore, this review presents information on the occurrence of enteric viruses of public health importance, diseases associated with human exposure to enteric viruses, assessment of their presence in contaminated water, and their removal in water and wastewater sources. In order to prevent illnesses associated with human exposure to viral contaminated water, we suggest the regular viral monitoring of treated wastewater before discharging it into the environment. Furthermore, we highlight the need for more research to focus on the development of more holistic disinfection methods that will inactivate waterborne viruses in municipal wastewater discharges, as this is highly needed to curtail the public health effects of human exposure to contaminated water. Moreover, such a method must be devoid of disinfection by-products that have mutagenic and carcinogenic potential.

Appraisal for the Potential of Viral and Nonviral Vectors in Gene Therapy: A Review

Over the past few decades, gene therapy has gained immense importance in medical research as a promising treatment strategy for diseases such as cancer, AIDS, Alzheimer's disease, and many genetic disorders. When a gene needs to be delivered to a target cell inside the human body, it has to pass a large number of barriers through the extracellular and intracellular environment. This is why the delivery of naked genes and nucleic acids is highly unfavorable, and gene delivery requires suitable vectors that can carry the gene cargo to the target site and protect it from biological degradation. To date, medical research has come up with two types of gene delivery vectors, which are viral and nonviral vectors. The ability of viruses to protect transgenes from biological degradation and their capability to efficiently cross cellular barriers have allowed gene therapy research to develop new approaches utilizing viruses and their different genomes as vectors for gene delivery. Although viral vectors are very efficient, science has also come up with numerous nonviral systems based on cationic lipids, cationic polymers, and inorganic particles that provide sustainable gene expression without triggering unwanted inflammatory and immune reactions, and that are considered nontoxic. In this review, we discuss in detail the latest data available on all viral and nonviral vectors used in gene delivery. The mechanisms of viral and nonviral vector-based gene delivery are presented, and the advantages and disadvantages of all types of vectors are also given.

Invasive pulmonary fungal infections in children with severe human adenovirus type 7 pneumonia: A retrospective study

BACKGROUND

There has been a rapid increase in the number of human adenovirus type 7 (HAdV-7) and invasive pulmonary fungal infections (IPFIs) co-infection.

METHODS

In this study, we included patients with confirmed HAdV-7 infection during the period from 2018 to 2019 to explore clinical characteristics of severe HAdV-7 pneumonia combined with IPFIs.

RESULTS

Among the 143 patients, 35 cases were co-infected with IPFIs. Others were assigned to the control group (n Z 108). Patients wereprone to be complicated with respiratory failure, heart failure and hemophagocytic syndromein IPFIs group. Thirty-one species of fungi were detected in the IPFIs group, among whichAspergillus was the most common species. Compared to control group, patients had lowerlevels of WBC, CD3þ T lymphocyte counts and CD19þ B lymphocyte counts in IPFIs group.

CONCLUSION

Aspergillus is the most common species in IPFIs combined with severe HAdV-7 pneumonia. For children with severe HAdV-7 pneumonia who are younger, have a long course of disease, and have been admitted to the ICU, we should predict the occurrence of IPFIs when there is multi-system dysfunction and the reduction of CD3+ T lymphocyte counts and CD19+ B lymphocyte counts in course of their disease.

Seroprevalence of neutralizing antibodies against adenovirus type 26 and 35 in healthy populations from Guangdong and Shandong provinces, China

Human adenoviruses type 26 (HAdV26) and type 35 (HAdV35) have increasingly become the choice of adenovirus vectors for vaccine application. However, the population pre-existing immunity to these two adenoviruses in China, which may reduce vaccine efficacy, remains largely unknown. Here, we established micro-neutralizing (MN) assays to investigate the seroprevalence of neutralizing antibodies (nAbs) against HAdV26 and HAdV35 in the general population of Guangdong and Shandong provinces, China. A total of 1184 serum samples were collected, 47.0% and 15.8% of which showed HAdV26 and HAdV35 nAb activity, respectively. HAdV26-seropositive individuals tended to have more moderate nAbs titers (201–1000), while HAdV35-seropositive individuals appeared to have more low nAbs titers (72–200). The seropositive rates of HAdV26 and HAdV35 in individuals younger than 20 years old were very low. The seropositive rates of HAdV26 increased with age before 70 years old and decreased thereafter, while HAdV35 seropositive rates did not show similar characteristics. Notably, the seropositive rates and nAb levels of both HAdV26 and HAdV35 were higher in Guangdong Province than in Shandong Province, but did not exert significant differences between males and females. The seroprevalence between HAdV26 and HAdV35 showed little correlation, and no significant cross-neutralizing activity was detected. These results clarified the characteristics of the herd immunity against HAdV26 and HAdV35, and provided information for the rational development and application of HAdV26 and HAdV35 as vaccine vectors in China.

•

We address the pre-existing immunity of HAdV26 and HAdV35.

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The overall seroprevalence of nAbs against HAdV26 and HAdV35 were 47.0% and 15.8%.

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The seroprevalence level of HAdV26 and HAdV35 differed in age and in district.

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Pre-existing immunity should be considered when adenoviral vectors are used.

Validation of a Classification Model Using Complete Blood Count to Predict Severe Human Adenovirus Lower Respiratory Tract Infections in Pediatric Cases

Background

Human adenovirus (HAdV) lower respiratory tract infections (LRTIs) are prone to severe cases and even cause death in children. Here, we aimed to develop a classification model to predict severity in pediatric patients with HAdV LRTIs using complete blood count (CBC).

Methods

The CBC parameters from pediatric patients with a diagnosis of HAdV LRTIs from 2013 to 2019 were collected during the disease's course. The data were analyzed as potential predictors for severe cases and were selected using a random forest model.

Results

We enrolled 1,652 CBC specimens from 1,069 pediatric patients with HAdV LRTIs in the present study. Four hundred and seventy-four patients from 2017 to 2019 were used as the discovery cohort, and 470 patients from 2013 to 2016 were used as the validation cohort. The monocyte ratio (MONO%) was the most obvious difference between the mild and severe groups at onset, and could be used as a marker for the early accurate prediction of the severity [area under the subject operating characteristic curve (AUROC): 0.843]. Four risk factors [MONO%, hematocrit (HCT), red blood cell count (RBC), and platelet count (PLT)] were derived to construct a classification model of severe and mild cases using a random forest model (AUROC: 0.931 vs. 0.903).

Conclusion

Monocyte ratio can be used as an individual predictor of severe cases in the early stages of HAdV LRTIs. The four risk factors model is a simple and accurate risk assessment tool that can predict severe cases in the early stages of HAdV LRTIs.

Prevalence of adenoviruses as ocular disease causatives in Saudi Arabia

Although Human Adenoviruses outbreaks are rare, there still could be a potential chance for those viruses to mutate and spread quickly in human populations with severe public health and socioeconomic consequences. Outbreaks often spread fairly quickly with considerable morbidity/mortality. Saudi Arabia's geopolitical and religious significance bring with it, millions of pilgrims, and tourists yearly. This presents a significant potential for HAdVs epidemics. This review shows that even with the mushrooming serotypes and genotypes, the scholarly knowledge on the nature, structure, transmission, and management of HAdVs is already well-established. Significant research is ongoing on pharmacological interventions, which, presently remain speculative and lacking in effectiveness. This review similarly uncovers a shortage of literature, both recent and dated, on epidemic keratoconjunctivitis in either Saudi Arabia or the Middle East.

mRNA- and Adenovirus-Based Vaccines against SARS-CoV-2 in HIV-Positive People

About two years have passed since the identification of SARS-CoV-2 in China. The rapid spread of this virus all over the world and its high transmissibility and pathogenicity in humans have resulted in a global pandemic. The negative impact of COVID-19 on health, society and the economy at the global level has pushed researchers and pharmaceutical companies to develop effective vaccines to fight SARS-CoV-2. Thanks to this collaborative effort, the first COVID-19 vaccine was developed in less than a year. Since then, several COVID-19 vaccines have been validated for use by the World Health Organization. Among these, mRNA- (BNT162b2 and mRNA1273) and adenovirus-based (ChAdOx1) vaccines were developed through the use of novel technologies. While all three of these vaccines have shown effectiveness against the COVID-19 disease and their immunogenicity was characterized in clinical trials in the general population, data on their efficacy and immunogenicity in people living with HIV (PLWH) are limited. In this review, we provide a description of the characteristics of mRNA- and adenovirus-based vaccines and of the immune response elicited in the general population by vaccination. Then we describe the use of these vaccines and their efficacy and immunogenicity in people living with HIV and we conclude with a discussion regarding some open questions concerning the use of mRNA- and adenovirus-based COVID-19 vaccines in PLWH.

Sensitivity of Human Mastadenovirus, the Causal Agent of Pharyngoconjunctival Fever, Epidemic Keratoconjunctivitis, and Hemorrhagic Cystitis in Immunocompromised Individuals, to Brincidofovir

Human mastadenovirus (HAdV), a linear double-stranded DNA (dsDNA) virus, is the causal agent of several diseases, including pharyngoconjunctival fever, epidemic keratoconjunctivitis, and hemorrhagic cystitis, in immunocompromised individuals. There are more than 100 reported types of adenoviruses, but the pathogenicity of many HAdVs remains unknown. Brincidofovir (BCV) is a hexadecyloxypropyl lipid conjugate of cidofovir (CDV) that is active against dsDNA viruses. Clinical effectiveness of BCV against certain HAdV species has been reported; however, its activity against novel HAdV types remains unknown. We investigated the half-maximal inhibitory concentration (IC₅₀) values of BCV for novel HAdV types and found that the epidemic keratoconjunctivitis-associated HAdV-D54 prevalent in the Asian region was the most susceptible. The mean overall IC₅₀ value of BCV was lower than that of CDV, indicating that BCV is effective against HAdVs, including the novel types.

IMPORTANCE We investigated the IC₅₀ values of BCV for novel HAdV types and found that the epidemic keratoconjunctivitis-associated HAdV-D54 prevalent in the Asian region was the most susceptible. In addition, the mean overall IC₅₀ value of BCV was lower than that of CDV, indicating that BCV is effective against HAdVs.

Breaking Entry-and Species Barriers: LentiBOOST® Plus Polybrene Enhances Transduction Efficacy of Dendritic Cells and Monocytes by Adenovirus 5

Due to their ability to trigger strong immune responses, adenoviruses (HAdVs) in general and the serotype5 (HAdV-5) in particular are amongst the most popular viral vectors in research and clinical application. However, efficient transduction using HAdV-5 is predominantly achieved in coxsackie and adenovirus receptor (CAR)-positive cells. In the present study, we used the transduction enhancer LentiBOOST^® comprising the polycationic Polybrene to overcome these limitations. Using LentiBOOST^®/Polybrene, we yielded transduction rates higher than 50% in murine bone marrow-derived dendritic cells (BMDCs), while maintaining their cytokine expression profile and their capability to induce T-cell proliferation. In human dendritic cells (DCs), we increased the transduction rate from 22% in immature (i)DCs or 43% in mature (m)DCs to more than 80%, without inducing cytotoxicity. While expression of specific maturation markers was slightly upregulated using LentiBOOST^®/Polybrene on iDCs, no effect on mDC phenotype or function was observed. Moreover, we achieved efficient HAdV5 transduction also in human monocytes and were able to subsequently differentiate them into proper iDCs and functional mDCs. In summary, we introduce LentiBOOST^® comprising Polybrene as a highly potent adenoviral transduction agent for new in-vitro applications in a set of different immune cells in both mice and humans.

Diagnostic biosensors for coronaviruses and recent developments

Coronaviruses are well known airborne viruses that infect humans, other mammals, and birds. COVID-19 is the disease caused by the last emerging type of corona viruses; SARS-CoV-2 which resulted in the ongoing pandemic. Since its first identification, SARS-CoV-2 has spread globally causing significant morbidity and mortality. Fast and reliable diagnostic methods are crucial to control the virus outbreak. In this chapter, we summarize the traditional methods used to detect corona viruses. Various biosensors used for the detection of the virus antibodies and antigens were briefly discussed. Different biosensing approaches for the detection of corona viruses were presented with special emphasis on the reported biosensors for the detection of SARS-CoV-2. Major advancements in the biosensors area for corona viruses such as the use of cotton, magnetic nanoparticles, graphene, gold nanoparticles, and portable devices are highlighted. The challenges and future perspectives in the biosensors for the detection of corona viruses are discussed.

Human Adenovirus Serotype 3 Infection Modulates the Biogenesis and Composition of Lung Cell-Derived Extracellular Vesicles

Adenovirus (Ad) is a major causal agent of acute respiratory infections. However, they are a powerful delivery system for gene therapy and vaccines. Some Ad serotypes antagonize the immune system leading to meningitis, conjunctivitis, gastroenteritis, and/or acute hemorrhagic cystitis. Studies have shown that the release of small, membrane-derived extracellular vesicles (EVs) may offer a mechanism by which viruses can enter cells via receptor-independent entry and how they influence disease pathogenesis and/or host protection considering their existence in almost all bodily fluids. We proposed that Ad3 could alter EV biogenesis, composition, and trafficking and may stimulate various immune responses in vitro. In the present study, we evaluated the impact of in vitro infection with Ad3 vector on EV biogenesis and composition in the human adenocarcinoma lung epithelial cell line A549. Cells were infected in an exosome-free media at different multiplicity of infections (MOIs) and time points. The cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and fluorometric calcein-AM. EVs were isolated via ultracentrifugation. Isolated EV proteins were quantified and evaluated via nanoparticle tracking, transmission electron microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunoblotting assays. The cell viability significantly decreased with an increase in MOI and incubation time. A significant increase in particle mean sizes, concentrations, and total EV protein content was detected at higher MOIs when compared to uninfected cells (control group). A549 cell-derived EVs revealed the presence of TSG101, tetraspanins CD9 and CD63, and heat shock proteins 70 and 100 with significantly elevated levels of Rab5, 7, and 35 at higher MOIs (300, 750, and 1500) when compared to the controls. Our findings suggested Ad3 could modulate EV biogenesis, composition, and trafficking which could impact infection pathogenesis and disease progression. This study might suggest EVs could be diagnostic and therapeutic advancement to Ad infections and other related viral infections. However, further investigation is warranted to explore the underlying mechanism(s).

Delivery of Anti-IFNAR1 shRNA to Hepatic Cells Decreases IFNAR1 Gene Expression and Improves Adenoviral Transduction and Transgene Expression

Chronic liver injury leads to advanced fibrosis, cirrhosis, and hepatocellular carcinoma. Genetical cell treatment related to the use of adenovirus (Ads) has proven to be beneficial and efficient in the recovery of hepatic diseases. Nevertheless, they are highly immunogenic and trigger an immune response where interferons type 1 (IFN-I) play a very important role. Three shRNAs against the Interferon-1 receptor (IFNAR1) were designed and cloned in pENTR/U6 plasmid and amplified in DH5α cells. Huh7 cells were transfected with these plasmids in the presence or absence of 1 × 10⁹ viral particles/ml of adenovirus containing the green fluorescent protein gene used as a reporter. Transfection with the shRNA plasmids partially inhibited the IFNAR1 expression. This inhibition substantially decreased antiviral response, demonstrated by the decrease of IFNAR1, IFN-α, and TNF-α gene expression, and the decrease at protein levels of IFNAR1, Protein kinase RNA-activated (PKR), and phosphorylated STAT1, allowing higher adenoviral transduction and transgene expression. Interestingly it was seen shRNA inhibited macrophage activation. These results suggest that the inhibition of the IFN-I pathway could be a strategy to minimize the immune response against Adenoviral vectors allowing higher Adenovirus transduction extending the transgene expression.

Human adenoviruses in paediatric patients with respiratory tract infections in Beijing, China

Background

Human adenoviruse (HAdV) is a major pathogen of paediatric respiratory tract infections (RTIs). Mutation or recombination of HAdV genes may cause changes in its pathogenicity and transmission. We described the epidemiology and genotypic diversity of HAdV in hospitalized children with RTIs in Beijing, China.

Methods

Nasopharyngeal aspirates were collected from hospitalized children with RTIs from April 2018 to March 2019. HAdVs were detected by a quantitative real-time PCR, and the hexon gene was used for phylogenetic analysis.

Results

Among 1572 samples, 90 (5.72%) were HAdV-positive. The HAdV detection rate was highest in November and July. Among HAdV-positive children, 61.11% (55/90) were co-infected with other respiratory viruses, the most common of which were human respiratory syncytial virus and human rhinovirus. The main diagnosis was bronchopneumonia, most patient have cough and fever. Children with a high viral load were more likely to have a high fever (P = 0.041) and elevated WBC count (P = 0.000). Of 55 HAdV-positive specimens, HAdV-B (63.64%), HAdV-C (27.27%), and HAdV-E (9.09%) were main epidemic species. Phylogenetic analysis indicated that hexon sequences of three samples were on the same branch with the recombinant HAdV strain (CBJ113), which was circulating in Beijing since 2016.

Conclusion

The HAdV-B3 and HAdV-B7 are the main epidemic strains in Beijing, and the recombinant HAdV-C strain CBJ113 has formed an epidemic trend.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01661-6.

Biology and Pathogenesis of SARS-CoV-2: Understandings for Therapeutic Developments against COVID-19

Coronaviruses are positive sense, single-stranded, enveloped, and non-segmented RNA viruses that belong to the Coronaviridae family within the order Nidovirales and suborder Coronavirinae. Two Alphacoronavirus strains: HCoV-229E and HCoV-NL63 and five Betacoronaviruses: HCoV-HKU1, HCoV-OC43, SARS-CoV, MERS-CoV, and SARS-CoV-2 have so far been recognized as Human Coronaviruses (HCoVs). Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 is currently the greatest concern for humanity. Despite the overflow of research on SARS-CoV-2 and other HCoVs published every week, existing knowledge in this area is insufficient for the complete understanding of the viruses and the diseases caused by them. This review is based on the analysis of 210 published works, and it attempts to cover the basic biology of coronaviruses, including the genetic characteristics, life cycle, and host-pathogen interaction, pathogenesis, the antiviral drugs, and vaccines against HCoVs, especially focusing on SARS-CoV-2. Furthermore, we will briefly discuss the potential link between extracellular vesicles (EVs) and SARS-CoV-2/COVID-19 pathophysiology.

Reviewing Antiviral Research Against Viruses Causing Human Diseases - A Structure Guided Approach

The littlest of all the pathogens, viruses have continuously been the foremost strange microorganisms to consider. Viral Infections can cause extreme sicknesses as archived by the HIV/AIDS widespread or the later Ebola or Zika episodes. Apprehensive framework distortions are too regularly watched results of numerous viral contaminations. Besides, numerous infections are oncoviruses, which can trigger different sorts of cancer. Nearly every year a modern infection species rises debilitating the world populace with an annihilating episode. Subsequently, the need of creating antivirals to combat such rising infections. In any case, from the innovation of to begin with antiviral medicate Idoxuridine in 1962 to the revelation of Baloxavir marboxil (Xofluza) that was FDA-approved in 2018, the hone of creating antivirals has changed significantly. In this article, different auxiliary science strategies have been described that can be referral for therapeutics innovation.

Understanding Post Entry Sorting of Adenovirus Capsids; A Chance to Change Vaccine Vector Properties

Adenovirus vector-based genetic vaccines have emerged as a powerful strategy against the SARS-CoV-2 health crisis. This success is not unexpected because adenoviruses combine many desirable features of a genetic vaccine. They are highly immunogenic and have a low and well characterized pathogenic profile paired with technological approachability. Ongoing efforts to improve adenovirus-vaccine vectors include the use of rare serotypes and non-human adenoviruses. In this review, we focus on the viral capsid and how the choice of genotypes influences the uptake and subsequent subcellular sorting. We describe how understanding capsid properties, such as stability during the entry process, can change the fate of the entering particles and how this translates into differences in immunity outcomes. We discuss in detail how mutating the membrane lytic capsid protein VI affects species C viruses' post-entry sorting and briefly discuss if such approaches could have a wider implication in vaccine and/or vector development.

Infection of Bronchial Epithelial Cells by the Human Adenoviruses A12, B3, and C2 Differently Regulates the Innate Antiviral Effector APOBEC3B

Human adenoviruses (HAdVs) are a large family of DNA viruses that include more than 100 genotypes divided into seven species (A to G) and induce respiratory tract infections, gastroenteritis, and conjunctivitis. Genetically modified adenoviruses are also used as vaccines, gene therapies, and anticancer treatments. The APOBEC3s are a family of cytidine deaminases that restrict viruses by introducing mutations in their genomes. Viruses developed different strategies to cope with the APOBEC3 selection pressure, but nothing is known on the interplay between the APOBEC3s and the HAdVs. In this study, we focused on three HAdV strains: the B3 and C2 strains, as they are very frequent, and the A12 strain, which is less common but is oncogenic in animal models. We demonstrated that the three HAdV strains induce a similar APOBEC3B upregulation at the transcriptional level. At the protein level, however, APOBEC3B is abundantly expressed during HAdV-A12 and -C2 infection and shows a nuclear distribution. On the contrary, APOBEC3B is barely detectable in HAdV-B3-infected cells. APOBEC3B deaminase activity is detected in total protein extracts upon HAdV-A12 and -C2 infection. Bioinformatic analysis demonstrates that the HAdV-A12 genome bears a stronger APOBEC3 evolutionary footprint than that of the HAdV-C2 and HAdV-B3 genomes. Our results show that HAdV infection triggers the transcriptional upregulation of the antiviral innate effector APOBEC3B. The discrepancies between the APOBEC3B mRNA and protein levels might reflect the ability of some HAdV strains to antagonize the APOBEC3B protein. These findings point toward an involvement of APOBEC3B in HAdV restriction and evolution. IMPORTANCE The APOBEC3 family of cytosine deaminases has important roles in antiviral innate immunity and cancer. Notably, APOBEC3A and APOBEC3B are actively upregulated by several DNA tumor viruses and contribute to transformation by introducing mutations in the cellular genome. Human adenoviruses (HAdVs) are a large family of DNA viruses that cause generally asymptomatic infections in immunocompetent adults. HAdVs encode several oncogenes, and some HAdV strains, like HAdV-A12, induce tumors in hamsters and mice. Here, we show that HAdV infection specifically promotes the expression of the APOBEC3B gene. We report that infection with the A12 strain induces a strong expression of an enzymatically active APOBEC3B protein in bronchial epithelial cells. We provide bioinformatic evidence that HAdVs' genomes and notably the A12 genome are under APOBEC3 selection pressure. Thus, APOBEC3B might contribute to adenoviral restriction, diversification, and oncogenic potential of particular strains.

Vaccines based on replication incompetent Ad26 viral vectors: Standardized template with key considerations for a risk/benefit assessment

Replication-incompetent adenoviral vectors have been under investigation as a platform to carry a variety of transgenes, and express them as a basis for vaccine development. A replication-incompetent adenoviral vector based on human adenovirus type 26 (Ad26) has been evaluated in several clinical trials. The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety and features of recombinant viral vector vaccines. This paper reviews features of the Ad26 vectors, including tabulation of safety and risk assessment characteristics of Ad26-based vaccines. In the Ad26 vector, deletion of E1 gene rendering the vector replication incompetent is combined with additional genetic engineering for vaccine manufacturability and transgene expression optimization. These vaccines can be manufactured in mammalian cell lines at scale providing an effective, flexible system for high-yield manufacturing. Ad26 vector vaccines have favorable thermostability profiles, compatible with vaccine supply chains. Safety data are compiled in the Ad26 vaccine safety database version 4.0, with unblinded data from 23 ongoing and completed clinical studies for 3912 participants in five different Ad26-based vaccine programs. Overall, Ad26-based vaccines have been well tolerated, with no significant safety issues identified. Evaluation of Ad26-based vaccines is continuing, with >114,000 participants vaccinated as of 4th September 2020. Extensive evaluation of immunogenicity in humans shows strong, durable humoral and cellular immune responses. Clinical trials have not revealed impact of pre-existing immunity to Ad26 on vaccine immunogenicity, even in the presence of Ad26 neutralizing antibody titers or Ad26-targeting T cell responses at baseline. The first Ad26-based vaccine, against Ebola virus, received marketing authorization from EC on 1st July 2020, as part of the Ad26.ZEBOV, MVA-BN-Filo vaccine regimen. New developments based on Ad26 vectors are underway, including a COVID-19 vaccine, which is currently in phase 3 of clinical evaluation.

Novel approaches for vaccine development

Vaccines are critical tools for maintaining global health. Traditional vaccine technologies have been used across a wide range of bacterial and viral pathogens, yet there are a number of examples where they have not been successful, such as for persistent infections, rapidly evolving pathogens with high sequence variability, complex viral antigens, and emerging pathogens. Novel technologies such as nucleic acid and viral vector vaccines offer the potential to revolutionize vaccine development as they are well-suited to address existing technology limitations. In this review, we discuss the current state of RNA vaccines, recombinant adenovirus vector-based vaccines, and advances from biomaterials and engineering that address these important public health challenges.

Plasma TNFSF13B and TNFSF14 Function as Inflammatory Indicators of Severe Adenovirus Pneumonia in Pediatric Patients

Background

Human adenoviruses (HAdV) infection caused pneumonia remains a major threat to global children health. Currently, diagnosis of severe HAdV pneumonia in children is hampered by the lack of specific biomarkers. Also, the severity of adenovirus pneumonia in pediatric patients is generally based on clinical features and existing biomarkers do not reliably correlate to clinical severity. Here, we asked whether local and systemic inflammatory mediators could act as biomarkers predicting severe HAdV pneumonia in children.

Methods

Totally 37 common inflammatory protein levels were determined by Luminex assay in plasma and bronchoalveolar lavage (BAL) from pediatric patients who were diagnosed with HAdV pneumonia, and their correlation with the disease severity and lung lesion were assessed using statistical and bioinformatic analysis.

Results

Among 37 inflammatory cytokines, the protein levels of 4 TNF superfamily (TNFSF) members and their receptors (TNF receptor superfamily, TNFRSF) [TNFSF13B, TNFSF14, sTNF-R1 and sTNF-R2] in the plasma and 7 TNFSF/TNFRSF members [TNFSF12, TNFSF13, TNFSF13B, TNFSF14, TNFRSF8, sTNF-R1, and sTNF-R2] in the BAL were enhanced in patients with HAdV pneumonia compared with control subjects with airway foreign body. Moreover, the protein levels of all the tested TNFSF/TNFRSF members (except TNFSF12) were elevated in the BAL of severe group compared with non-severe HAdV pneumonia patients, while only TNFSF13B and TNFSF14 were dramatically increased in the plasma of severe cases, and positively related to the plasma CRP levels. In addition, ROC analysis indicated that TNFSF13B and TNFSF14 displayed a great potential to predict severe HAdV pneumonia.

Conclusion

In pediatric HAdV pneumonia, TNFSF/TNFRSF members function as key molecules in local and systemic inflammatory network, and the plasma TNFSF13B and TNFSF14 may be the potential local and systemic inflammatory indicators of severe HAdV pneumonia in pediatric patients.