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1.
Microbiol Spectr ; 11(3): e0330222, 2023 Jun 15.
Article in English | MEDLINE | ID: covidwho-20245196

ABSTRACT

Antarctica is a unique environment due to its extreme meteorological and geological conditions. In addition to this, its relative isolation from human influences has kept it undisturbed. This renders our limited understanding of its fauna and its associated microbial and viral communities a relevant knowledge gap to fill. This includes members of the order Charadriiformes such as snowy sheathbills. They are opportunistic predator/scavenger birds distributed on Antarctic and sub-Antarctic islands that are in frequent contact with other bird and mammal species. This makes them an interesting species for surveillance studies due to their high potential for the acquisition and transport of viruses. In this study, we performed whole-virome and targeted viral surveillance for coronaviruses, paramyxoviruses, and influenza viruses in snowy sheathbills from two locations, the Antarctic Peninsula and South Shetland. Our results suggest the potential role of this species as a sentinel for this region. We highlight the discovery of two human viruses, a member of the genus Sapovirus GII and a gammaherpesvirus, and a virus previously described in marine mammals. Here, we provide insight into a complex ecological picture. These data highlight the surveillance opportunities provided by Antarctic scavenger birds. IMPORTANCE This article describes whole-virome and targeted viral surveillance for coronaviruses, paramyxoviruses, and influenza viruses in snowy sheathbills from the Antarctic Peninsula and South Shetland. Our results suggest an important role of this species as a sentinel for this region. This species' RNA virome showcased a diversity of viruses likely tied to its interactions with assorted Antarctic fauna. We highlight the discovery of two viruses of likely human origin, one with an intestinal impact and another with oncogenic potential. Analysis of this data set detected a variety of viruses tied to various sources (from crustaceans to nonhuman mammals), depicting a complex viral landscape for this scavenger species.


Subject(s)
Charadriiformes , Expeditions , Viruses , Animals , Humans , Antarctic Regions , Virome , Prospective Studies , Birds , Viruses/genetics , Phylogeny , Mammals
2.
J Mol Biol ; 435(15): 168173, 2023 Jun 08.
Article in English | MEDLINE | ID: covidwho-20241205

ABSTRACT

Although one member of the poxvirus family, variola virus, has caused one of the most devastating human infections worldwide, smallpox, the knowledge gained over the last 30 years on the molecular, virological and immunological mechanisms of these viruses has allowed the use of members of this family as vectors for the generation of recombinant vaccines against numerous pathogens. In this review, we cover different aspects of the history and biology of poxviruses with emphasis on their application as vaccines, from first- to fourth-generation, against smallpox, monkeypox, emerging viral diseases highlighted by the World Health Organization (COVID-19, Crimean-Congo haemorrhagic fever, Ebola and Marburg virus diseases, Lassa fever, Middle East respiratory syndrome and severe acute respiratory syndrome, Nipah and other henipaviral diseases, Rift Valley fever and Zika), as well as against one of the most concerning prevalent virus, the Human Immunodeficiency Virus, the causative agent of Acquired Immunodeficiency Syndrome. We discuss the implications in human health of the 2022 monkeypox epidemic affecting many countries, and the rapid prophylactic and therapeutic measures adopted to control virus dissemination within the human population. We also describe the preclinical and clinical evaluation of the Modified Vaccinia virus Ankara and New York vaccinia virus poxviral strains expressing heterologous antigens from the viral diseases listed above. Finally, we report different approaches to improve the immunogenicity and efficacy of poxvirus-based vaccine candidates, such as deletion of immunomodulatory genes, insertion of host-range genes and enhanced transcription of foreign genes through modified viral promoters. Some future prospects are also highlighted.

3.
Front Immunol ; 14: 1156758, 2023.
Article in English | MEDLINE | ID: covidwho-2314352

ABSTRACT

Correlates of protection (CoP) are biological parameters that predict a certain level of protection against an infectious disease. Well-established correlates of protection facilitate the development and licensing of vaccines by assessing protective efficacy without the need to expose clinical trial participants to the infectious agent against which the vaccine aims to protect. Despite the fact that viruses have many features in common, correlates of protection can vary considerably amongst the same virus family and even amongst a same virus depending on the infection phase that is under consideration. Moreover, the complex interplay between the various immune cell populations that interact during infection and the high degree of genetic variation of certain pathogens, renders the identification of immune correlates of protection difficult. Some emerging and re-emerging viruses of high consequence for public health such as SARS-CoV-2, Nipah virus (NiV) and Ebola virus (EBOV) are especially challenging with regards to the identification of CoP since these pathogens have been shown to dysregulate the immune response during infection. Whereas, virus neutralising antibodies and polyfunctional T-cell responses have been shown to correlate with certain levels of protection against SARS-CoV-2, EBOV and NiV, other effector mechanisms of immunity play important roles in shaping the immune response against these pathogens, which in turn might serve as alternative correlates of protection. This review describes the different components of the adaptive and innate immune system that are activated during SARS-CoV-2, EBOV and NiV infections and that may contribute to protection and virus clearance. Overall, we highlight the immune signatures that are associated with protection against these pathogens in humans and could be used as CoP.


Subject(s)
COVID-19 , Ebolavirus , Hemorrhagic Fever, Ebola , Henipavirus Infections , Humans , Henipavirus Infections/prevention & control , SARS-CoV-2
4.
Anaesthesia ; 78(5): 626-635, 2023 05.
Article in English | MEDLINE | ID: covidwho-2310011

ABSTRACT

Viral infections form a substantial part of the intensive care workload, even before the recent and ongoing COVID-19 pandemic. The growing availability of molecular diagnostics for viral infections has led to increased recognition of these pathogens. This additional information, however, provides new challenges for interpretation and management. As the SARS-CoV-2 pandemic has amply demonstrated, the emergence and global spread of novel viruses are likely to provide continued challenges for critical care physicians into the future. This article will provide an overview of viral infections relevant to the critical care physician, discussing the diagnosis and management of respiratory viral infections, blood borne and enteric viruses. We will also discuss herpesviridae complications, commonly seen due to reactivation of latent infections. Further, we explore some rarer and emerging viruses, including recognition of viral haemorrhagic fevers, and briefly discuss post-viral syndromes which may present to the intensive care unit. Finally, we will discuss infection control and its importance in preventing nosocomial viral transmission.


Subject(s)
COVID-19 , Virus Diseases , Humans , COVID-19/prevention & control , SARS-CoV-2 , Pandemics , Virus Diseases/diagnosis , Virus Diseases/therapy , Critical Care
6.
J Clin Virol Plus ; 2(3): 100102, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-2292559

ABSTRACT

During the early stages of an epidemic, obtaining reliable data is a challenge, especially on a global scale. The COVID-19 pandemic has underlined the importance of having "open data" (i.e., data which are made accessible and available in a standardized machine-readable format and under a license that allows it to be re-used and reshared) to inform health policy decisions and improve clinical trials. The main goal of our work is to provide effective, timely and comprehensive data to investigate this emerging virus, i.e., the acute hepatitis of unknown origin in children. These data can be used: 1) to conduct real-time situation analysis, and early and timely diagnosis for effective containment; 2) to facilitate coordination and collaboration between national and local governments; 3) to inform citizens on the spread of the disease in the world; and 4) to support governments in the future prevention decisions.

7.
J Clin Virol Plus ; 2(4): 100114, 2022 Nov.
Article in English | MEDLINE | ID: covidwho-2252915

ABSTRACT

Background: The current out-of-Africa 2022 outbreak of Monkeypox requires a coordinated, international response through the rapid sharing of data and research results, as we have seen with COVID-19 and the previous Ebola and Zika outbreaks, which demonstrated how important real-world data are to inform public health, to create surveillance systems, to determine policy decisions and to improve clinical trials. Objectives: To support global response efforts by providing public access to real-time Monkeypox-related data for effective use of open data that could accelerate scientific knowledge and discoveries in terms of understanding, preventing, and treating the disease. In practice, to create a new surveillance system easy to consult and utilize. Study design: This work aims to build a surveillance system, namely EpiMPX, that allows researchers and policymakers to monitor the impact of Monkeypox in Europe, with a special focus on the epidemic trends in the Italian regions, based on an open-access database containing information on the laboratory confirmed Monkeypox cases reported by EU/EEA countries and updated once a week. In addition, users will be provided open-access R codes to estimate key epidemiological parameters such as the reproduction number (updating the Serial Interval distribution when new estimates will be published) and produce real-time results on their devices. Results: EpiMPX monitors the space-time distribution of cases and their characteristics, such as age, gender, symptoms, clinical status, and sexual orientation, when available. Even if it is currently too early for reliable calculation of epidemiological parameters, we estimated reproduction number R t in European countries with more than 28 days of observed incidence, assuming that the Serial Interval (SI) early estimate in Italy is valid for other countries too. This provides a direct visual assessment of the geographic distribution of risk areas as well as insights into the evolution of the outbreak over time. Italian data were evaluated concerning gender, region prevalence and cumulative data. Conclusions: The proposed EpiMPX surveillance system provides an overview of the European and Italian Monkeypox epidemiological situation with an open-access database to support epidemiological understanding of the origins and transmission dynamics of the disease with informative graphical outputs. These data confirmed the prevalent expression of Monkeypox within males, both in Europe and Italy. European MSM patients were affected by Monkeypox in a high percentage, confirming close sexual contact and possible sexual transmission. For the first time, Italian data on the regional distribution of cases and gender distribution were graphically evaluated. The data and research results are freely available and can be easily enriched to provide a prompt response to the scientific community and accelerate global efforts to contain the Monkeypox virus.

8.
Handbook of Environmental Chemistry ; 114:289-305, 2023.
Article in English | Scopus | ID: covidwho-2244290

ABSTRACT

Human pathogenic viruses can be introduced into sewage sludge and soils via fecal material from a variety of human activities. These contaminated matrices can play a substantial role in the dispersion of pathogenic viruses in the environment, constituting a potential public health problem if they enter the water cycle or the food chain. However, the interactions between pathogenic viruses and these matrices have received less attention compared to other environmental compartments. Understanding the presence of viruses, their persistence and fate in solid or semi-solid matrices like sludge and soil is important for the effective control of the infections they may cause. In this chapter, we summarize current knowledge about human pathogenic viruses in sewage sludge and soil, their importance in public health, and the factors that govern their transport and persistence in soil matrices. We also review the occurrence and variety of common and emerging viruses excreted in the feces and their presence in sewage sludge and soil, as well as the potential use of certain viruses as indicators of fecal pollution. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

9.
Travel Med Infect Dis ; 52: 102535, 2023.
Article in English | MEDLINE | ID: covidwho-2245079
10.
Microb Pathog ; 176: 106027, 2023 Mar.
Article in English | MEDLINE | ID: covidwho-2232395

ABSTRACT

While monkeypox was previously found in Africa, the bulk of occurrences in the present outbreak are being reported in many countries. It is not yet known how this outbreak began, and as the COVID-19 crisis begins to abate, numerous nations throughout the world are now contending with a novel outbreak. Monkeypox is a transmissible virus between animals and humans, belonging to the Orthopoxvirus genus of the Poxviridae family. In the 1970s, cases of monkeypox began increasing due to the cessation of vaccination against smallpox, which drew international attention. The virus was named monkeypox because it was first observed in macaque monkeys. It is thought to be transmitted by several different rodents and small mammals, though the origin of the virus is not known. Monkeypox, while occasionally transmitted from one human to another, can be disseminated through the inhalation of droplets or through contact with the skin lesions of an infected individual. Unfortunately, there is no definitive cure for monkeypox; however, supportive care can be offered to ameliorate its symptoms. In severe cases, medications like tecovirimat may be administered. However, there are no established guidelines for symptom management in monkeypox cases. In this article we have discussed about different aspects of monkeypox including viral structure, transmission, replication, clinical manifestations, vaccination, treatment and current prevalence in the world to understand it better and give insight to the future studies.


Subject(s)
COVID-19 , Monkeypox , Animals , Humans , Monkeypox virus , Disease Outbreaks , Africa , Mammals
11.
Biomed Pharmacother ; 156: 113850, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2085961

ABSTRACT

As diseases caused by new and emerging viruses continue to be a major threat to humans and animals worldwide the need for new therapeutic options intensifies. A wide variety of viruses including Influenza A virus, Human immunodeficiency virus, Middle East respiratory syndrome coronavirus and severe acute respiratory syndrome coronavirus require ion channels for efficient replication. Thus, targeting host ion channels may serve as an effective means to attenuate virus replication and help treat viral diseases. Targeting host ion channels is an attractive therapeutic option because a range of ion channel-blocking compounds already exist for the treatment of other human diseases and some of these possess in vitro and sometimes in vivo antiviral activity. Therefore, identifying the specific ion channels involved in replicative cycles could provide opportunities to repurpose these ion channel inhibitors for treating viral diseases. Furthermore, optimised methodologies for identifying effective ion channel targeting drugs and their mechanisms of action could enable rapid responses to newly emerged viruses. This review discusses the potential of ion channels as suitable drug targets to treat diseases caused by viruses by describing known ion channel targeting drugs including their antiviral activity; by summarising prior research demonstrating the requirement for host ion channels for efficient replication of some viruses; and by hypothesising about the role these drugs might play in our ongoing fight against viral diseases.


Subject(s)
Drug Repositioning , Virus Diseases , Animals , Humans , Virus Replication , Virus Diseases/drug therapy , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Ion Channels
12.
Handbook of Environmental Chemistry ; 114:289-305, 2023.
Article in English | Scopus | ID: covidwho-2047962

ABSTRACT

Human pathogenic viruses can be introduced into sewage sludge and soils via fecal material from a variety of human activities. These contaminated matrices can play a substantial role in the dispersion of pathogenic viruses in the environment, constituting a potential public health problem if they enter the water cycle or the food chain. However, the interactions between pathogenic viruses and these matrices have received less attention compared to other environmental compartments. Understanding the presence of viruses, their persistence and fate in solid or semi-solid matrices like sludge and soil is important for the effective control of the infections they may cause. In this chapter, we summarize current knowledge about human pathogenic viruses in sewage sludge and soil, their importance in public health, and the factors that govern their transport and persistence in soil matrices. We also review the occurrence and variety of common and emerging viruses excreted in the feces and their presence in sewage sludge and soil, as well as the potential use of certain viruses as indicators of fecal pollution. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

13.
Viruses ; 14(6)2022 06 13.
Article in English | MEDLINE | ID: covidwho-1911626

ABSTRACT

In the last few years, the sudden outbreak of COVID-19 caused by SARS-CoV-2 proved the crucial importance of understanding how emerging viruses work and proliferate, in order to avoid the repetition of such a dramatic sanitary situation with unprecedented social and economic costs. West Nile Virus is a mosquito-borne pathogen that can spread to humans and induce severe neurological problems. This RNA virus caused recent remarkable outbreaks, notably in Europe, highlighting the need to investigate the molecular mechanisms of its infection process in order to design and propose efficient antivirals. Here, we resort to all-atom Molecular Dynamics simulations to characterize the structure of the 5'-untranslated region of the West Nile Virus genome and its specific recognition by the human innate immune system via oligoadenylate synthetase. Our simulations allowed us to map the interaction network between the viral RNA and the host protein, which drives its specific recognition and triggers the host immune response. These results may provide fundamental knowledge that can assist further antivirals' design, including therapeutic RNA strategies.


Subject(s)
COVID-19 , West Nile Fever , West Nile virus , 5' Untranslated Regions , Animals , Antiviral Agents , Humans , Immune System , SARS-CoV-2/genetics , West Nile virus/physiology
14.
Viruses ; 14(6)2022 06 11.
Article in English | MEDLINE | ID: covidwho-1911622

ABSTRACT

Targeted virome enrichment and sequencing (VirCapSeq-VERT) utilizes a pool of oligos (baits) to enrich all known-up to 2015-vertebrate-infecting viruses, increasing their detection sensitivity. The hybridisation of the baits to the target sequences can be partial, thus enabling the detection and genomic reconstruction of novel pathogens with <40% genetic diversity compared to the strains used for the baits' design. In this study, we deploy this method in multiplexed mixes of viral extracts, and we assess its performance in the unbiased detection of DNA and RNA viruses after cDNA synthesis. We further assess its efficiency in depleting various background genomic material. Finally, as a proof-of-concept, we explore the potential usage of the method for the characterization of unknown, emerging human viruses, such as SARS-CoV-2, which may not be included in the baits' panel. We mixed positive samples of equimolar DNA/RNA viral extracts from SARS-CoV-2, coronavirus OC43, cytomegalovirus, influenza A virus H3N2, parvovirus B19, respiratory syncytial virus, adenovirus C and coxsackievirus A16. Targeted virome enrichment was performed on a dsDNA mix, followed by sequencing on the NextSeq500 (Illumina) and the portable MinION sequencer, to evaluate its usability as a point-of-care (PoC) application. Genome mapping assembly was performed using viral reference sequences. The untargeted libraries contained less than 1% of total reads mapped on most viral genomes, while RNA viruses remained undetected. In the targeted libraries, the percentage of viral-mapped reads were substantially increased, allowing full genome assembly in most cases. Targeted virome sequencing can enrich a broad range of viruses, potentially enabling the discovery of emerging viruses.


Subject(s)
COVID-19 , SARS-CoV-2 , Genome, Viral , High-Throughput Nucleotide Sequencing/methods , Humans , Influenza A Virus, H3N2 Subtype , SARS-CoV-2/genetics , Virome/genetics
15.
Cell Chem Biol ; 29(7): 1113-1125.e6, 2022 07 21.
Article in English | MEDLINE | ID: covidwho-1894864

ABSTRACT

The increasingly frequent outbreaks of pathogenic viruses have underlined the urgent need to improve our arsenal of antivirals that can be deployed for future pandemics. Innate immunity is a powerful first line of defense against pathogens, and compounds that boost the innate response have high potential to act as broad-spectrum antivirals. Here, we harnessed localization-dependent protein-complementation assays (called Alpha Centauri) to measure the nuclear translocation of interferon regulatory factors (IRFs), thus providing a readout of innate immune activation following viral infection that is applicable to high-throughput screening of immunomodulatory molecules. As proof of concept, we screened a library of kinase inhibitors on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and identified Gilteritinib as a powerful enhancer of innate responses to viral infection. This immunostimulatory activity of Gilteritinib was found to be dependent on the AXL-IRF7 axis and results in a broad and potent antiviral activity against unrelated RNA viruses.


Subject(s)
COVID-19 , Virus Diseases , Antiviral Agents/pharmacology , Humans , Immunity, Innate , SARS-CoV-2 , Virus Diseases/drug therapy
16.
International Transaction Journal of Engineering Management & Applied Sciences & Technologies ; 13(4):10, 2022.
Article in English | English Web of Science | ID: covidwho-1884774

ABSTRACT

In light of current trends in virology, we performed social media analysis of 13 main topics in the area of virology and ranked these topics with metrics such as users, posts, engagement, and influence. These metrics were monitored against the 13 keywords on Twitter for the same period (i.e., from 27 November to 6 December 2021) for benchmarking purposes. The 13 main topics were "virological Science", " preventive vaccines", "therapeutic vaccines", "viral pathogenesis", "viral immunology", "antiviral strategies", "virus structure", "virus expression", "viral resistance", "emerging viruses", "interspecies transmission", "viruses and cancer" and " viral diseases". "viral diseases" recorded the highest number of users (i.e., 905 users) and the highest number of post (i.e., about 1K posts). The second-highest number of posts were monitored to be on "therapeutic vaccines" with 729 posts from 691 users. In terms of engagement, "viral diseases" (3.4 K) were found to be on the top followed by "viruses and cancer" (3.1K). Lastly, in terms of influence, "viral diseases" recorded 9.0 million influences followed by 6.6 million influences on "emerging viruses". In summary, "viral diseases" was found to be the most engaging and influential topic highest with the highest number of posts from most of the tweet users. In relation to trending hashtags in virology, #COVID19 recorded the highest number of hashtags, followed by # omicron, #sarscov2, #publichealth, #omicronvarient, #wuhan, #originofcovid, #fauci and #epidemiology. Word clouds showing the main area of discussion were also generated for these 13 main topics.

17.
J Med Virol ; 94(10): 4599-4610, 2022 10.
Article in English | MEDLINE | ID: covidwho-1872244

ABSTRACT

Historically, passive immunotherapy is an approved approach for protecting and treating humans against various diseases when other alternative therapeutic options are unavailable. Human polyclonal antibodies (hpAbs) can be made from convalescent human donor serum, although it is considered limited due to pandemics and the urgent requirement. Additionally, polyclonal antibodies (pAbs) could be generated from animals, but they may cause severe immunoreactivity and, once "humanized," may have lower neutralization efficiency. Transchromosomic bovines (TcBs) have been developed to address these concerns by creating robust neutralizing hpAbs, which are useful in preventing and/or curing human infections in response to hyperimmunization with vaccines holding adjuvants and/or immune stimulators over an extensive period. Unlike other animal-derived pAbs, potent hpAbs could be promptly produced from TcB in large amounts to assist against an outbreak scenario. Some of these highly efficacious TcB-derived antibodies have already neutralized and blocked diseases in clinical studies. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has numerous variants classified into variants of concern (VOCs), variants of interest (VOIs), and variants under monitoring. Although these variants possess different mutations, such as N501Y, E484K, K417N, K417T, L452R, T478K, and P681R, SAB-185 has shown broad neutralizing activity against VOCs, such as Alpha, Beta, Gamma, Delta, and Omicron variants, and VOIs, such as Epsilon, Iota, Kappa, and Lambda variants. This article highlights recent developments in the field of bovine-derived biotherapeutics, which are seen as a practical platform for developing safe and effective antivirals with broad activity, particularly considering emerging viral infections such as SARS-CoV-2, Ebola, Middle East respiratory syndrome coronavirus, Zika, human immunodeficiency virus type 1, and influenza A virus. Antibodies in the bovine serum or colostrum, which have been proved to be more protective than their human counterparts, are also reviewed.


Subject(s)
COVID-19 , HIV-1 , Hemorrhagic Fever, Ebola , Influenza A virus , Middle East Respiratory Syndrome Coronavirus , Zika Virus Infection , Zika Virus , Animals , Antibodies, Neutralizing , Antibodies, Viral/therapeutic use , Broadly Neutralizing Antibodies , COVID-19/therapy , Humans , Immunoglobulin G , Middle East Respiratory Syndrome Coronavirus/genetics , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
18.
Front Microbiol ; 13: 849781, 2022.
Article in English | MEDLINE | ID: covidwho-1834460

ABSTRACT

Viral infections are one of the major causes of human diseases that cause yearly millions of deaths and seriously threaten global health, as we have experienced with the COVID-19 pandemic. Numerous approaches have been adopted to understand viral diseases and develop pharmacological treatments. Among them, the study of virus-host protein-protein interactions is a powerful strategy to comprehend the molecular mechanisms employed by the virus to infect the host cells and to interact with their components. Experimental protein-protein interactions described in the scientific literature have been systematically captured into several molecular interaction databases. These data are organized in structured formats and can be easily downloaded by users to perform further bioinformatic and network studies. Network analysis of available virus-host interactomes allow us to understand how the host interactome is perturbed upon viral infection and what are the key host proteins targeted by the virus and the main cellular pathways that are subverted. In this review, we give an overview of publicly available viral-human protein-protein interactions resources and the community standards, curation rules and adopted ontologies. A description of the main virus-human interactome available is provided, together with the main network analyses that have been performed. We finally discuss the main limitations and future challenges to assess the quality and reliability of protein-protein interaction datasets and resources.

19.
Viruses ; 14(4)2022 04 15.
Article in English | MEDLINE | ID: covidwho-1792418

ABSTRACT

Lamellarin α 20-sulfate is a cell-impenetrable marine alkaloid that can suppress infection that is mediated by the envelope glycoprotein of human immunodeficiency virus type 1. We explored the antiviral action and mechanisms of this alkaloid against emerging enveloped RNA viruses that use endocytosis for infection. The alkaloid inhibited the infection of retroviral vectors that had been pseudotyped with the envelope glycoprotein of Ebola virus and SARS-CoV-2. The antiviral effects of lamellarin were independent of the retrovirus Gag-Pol proteins. Interestingly, although heparin and dextran sulfate suppressed the cell attachment of vector particles, lamellarin did not. In silico structural analyses of the trimeric glycoprotein of the Ebola virus disclosed that the principal lamellarin-binding site is confined to a previously unappreciated cavity near the NPC1-binding site and fusion loop, whereas those for heparin and dextran sulfate were dispersed across the attachment and fusion subunits of the glycoproteins. Notably, lamellarin binding to this cavity was augmented under conditions where the pH was 5.0. These results suggest that the final action of the alkaloid against Ebola virus is specific to events following endocytosis, possibly during conformational glycoprotein changes in the acidic environment of endosomes. Our findings highlight the unique biological and physicochemical features of lamellarin α 20-sulfate and should lead to the further use of broadly reactive antivirals to explore the structural mechanisms of virus replication.


Subject(s)
Alkaloids , COVID-19 Drug Treatment , Ebolavirus , Hemorrhagic Fever, Ebola , Alkaloids/pharmacology , Antiviral Agents/chemistry , Dextran Sulfate , Ebolavirus/metabolism , Glycoproteins , Hemorrhagic Fever, Ebola/drug therapy , Heparin/pharmacology , Humans , SARS-CoV-2 , Virus Internalization
20.
Front Immunol ; 13: 848054, 2022.
Article in English | MEDLINE | ID: covidwho-1793014

ABSTRACT

New vaccine design approaches, platforms, and immunization strategies might foster antiviral mucosal effector and memory responses to reduce asymptomatic infection and transmission in vaccinated individuals. Here, we investigated a combined parenteral and mucosal immunization scheme to induce local and serum antibody responses, employing the epitope-based antigens 3BT and NG19m. These antigens target the important emerging and re-emerging viruses PRRSV-2 and SARS-CoV-2, respectively. We assessed two versions of the 3BT protein, which contains conserved epitopes from the GP5 envelope protein of PRRSV-2: soluble and expressed by the recombinant baculovirus BacDual-3BT. On the other hand, NG19m, comprising the receptor-binding motif of the S protein of SARS-CoV-2, was evaluated as a soluble recombinant protein only. Vietnamese mini-pigs were immunized employing different inoculation routes: subcutaneous, intranasal, or a combination of both (s.c.-i.n.). Animals produced antigen-binding and neut1ralizing antibodies in serum and mucosal fluids, with varying patterns of concentration and activity, depending on the antigen and the immunization schedule. Soluble 3BT was a potent immunogen to elicit binding and neutralizing antibodies in serum, nasal mucus, and vaginal swabs. The vectored immunogen BacDual-3BT induced binding antibodies in serum and mucosae, but PRRSV-2 neutralizing activity was found in nasal mucus exclusively when administered intranasally. NG19m promoted serum and mucosal binding antibodies, which showed differing neutralizing activity. Only serum samples from subcutaneously immunized animals inhibited RBD-ACE2 interaction, while mini-pigs inoculated intranasally or via the combined s.c.-i.n. scheme produced subtle neutralizing humoral responses in the upper and lower respiratory mucosae. Our results show that intranasal immunization, alone or combined with subcutaneous delivery of epitope-based antigens, generates local and systemic binding and neutralizing antibodies. Further investigation is needed to evaluate the capability of the induced responses to prevent infection and reduce transmission.


Subject(s)
COVID-19 , Porcine respiratory and reproductive syndrome virus , Viral Vaccines , Animals , Antibodies, Neutralizing , Antibodies, Viral , Antibody Formation , COVID-19/prevention & control , Epitopes , Female , Immunization , SARS-CoV-2 , Swine , Swine, Miniature
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