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This special issue contains 23 articles that discuss various aspects of antiviral research, focusing on the contributions and legacy of Dr. Mike Bray, the retiring Editor-in-Chief of Antiviral Research. The articles cover a range of topics, including the underappreciated mouse model for Ebola virus disease, the history and impact of the mouse-adapted Ebola virus model, and the characterisation of CD-1 mice infected with different strains of Ebola virus. Other articles delve into transplacental vertical transmission of flaviviruses, the development of reverse genetic systems for SARS-CoV-2, and the mechanisms of action and drug resistance of nucleotide analogues against the virus. The special issue also explores therapeutics for flaviviral infections, alternative splicing in RNA virus infections, and targeted protein degradation as an antiviral approach.
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[Objective] To prepare broad-spectrum monoclonal antibody against N protein of avian infectious bronchitis virus (IBV), so as to lay a foundation for identifying conservative domain epitope of N protein and establish a universal IBV detection method. [Method] N protein of GX-YL5, a representative strain of IBV dominant serotype in Guangxi, was expressed in prokaryote. BALB/c mice were immunized with the purified protein. After the serum titer of the immunized mice reached 104 or more, the splenocytes were fused with SP2/0 myeloma cells. After screening by indirect ELISA, monoclonal antibody was prepared by ascites-induced method. Western blotting, IFA and indirect ELISA were used to identify the titer, subtype, reaction specificity and cross-reaction spectrum. And the prepared monoclonal antibody was used for immunohistochemical detection. And the prepared monoclonal antibody was used to detect the IBV in the trachea and kidney tissues of SPF chickens artificially infected with 4 representative IBV variants (GX-N130048, GX-N160421, GX-QZ171023 and GX-QZ170728). [Result] The prepared monoclonal antibody N2D5 had a titer greater than 217 and its subtype was IgG2b. The Western blotting and IFA results showed that the monoclonal antibody N2D5 only reacted with IBV, and were negative with Newcastle disease virus (NDV), infectious laryngotracheitis virus (ILTV), avian metapneumovirus (aMPV), infectious bursal disease virus (IBDV), avian leukosis virus (ALV) and Marek's disease virus (MDV). Monoclonal antibody N2D5 reacted with many genotypes in China and all 7 serotypes of IBV currently prevalent in Guangxi, including commonly used standard strains, vaccine strains and field strains. Immunohistochemistry showed that the virus signals could be detected in the trachea and kidney tissues of SPF chickens at different time after artificial infection of 3 representative IBV strains from chicken and 1 isolated strain from duck, which further proved its broad spectrum. [Conclusion] The monoclonal antibody N2D5 of IBV prepared based on hybridoma technology belongs to the IgG2b subtype. It has the characteristics of high specificity, wide response spectrum and strong binding ability with IBV. It can be used as a specific diagnostic antibody for clinical diagnosis of IBV and the study of virus distribution.
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In general, B and T lymphocytes, which are involved in adaptive immunity, are in charge of cell-mediated response and antibody-mediated immunity, respectively. Another subset of lymphocytes, known as natural killer (NK) cells, are innate effector cells. They serve as the body's initial line of defence against viral infections. They perform the task of eliminating stressed cells and are crucial for tumour immunity. These cells are capable of performing their killing function without clonal expansion and differentiation following activation. The NK cells will immediately eliminate infected host cells but other lymphocytes need lymphocyte proliferative response which takes several days and further differentiate into effector cells, so that they eliminate host cells infected by the viral pathogen. The NK cells also form a bridge between the adaptive and innate immunity and play significant roles during respiratory infection. Number and the role of NK cells correlate with the severity of severe acute respiratory syndrome (SARS);the number and the percentage of CD158b+ NK cells in severe SARS infection were significantly less in number than those with mild cases. Innate defence mechanisms, particularly NK cells, are able to control SARS infection even in the absence of T cells and antibodies, according to cellular immunological responses to SARS infection in mice. As a result, NK cells are crucial in the fight against viral infections of the respiratory system. As an innate immune system, they serve as the initial line of virus protection. It is possible to do additional research to take advantage of this NK cell trait and develop a cutting-edge therapeutic approach to fight developing respiratory viral diseases.
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In order to develop monoclonal antibody against Feline infectious peritonitis virus (FIPV) S1 protein, the truncated S1 protein (rS1) was expressed through Escherichia coli and subsequently purified. Then BALB/c mice were immunized with purified rSl. Three hybridoma cell strains, named 2D7,3D8 and 5G1, stably secreting antibodies against rSl were obtained by cell fusion and indirect ELISA screening. The identification of antibody subtype showed that antibody subtypes of 2D7,5G1 and 3d8 strains were IgG2a,IgG2a and IgGl,respectively. And the light chain of those three hybridoma cell strains was Kappa. Result of karyotype identification of hybridoma cells showed that the chromosome numbers of those three hybridoma cells were about 102,101 and 103, which was belonged to the karyotype of hybridoma. The titer of ascites antibody for indirect ELISA was 1 : 204 800, and monoclonal antibodies were purified. Moreover, all of 2D7,3D8 and 5G1 could react with rS1 by Western-blot and FIPV in cells by IFA. These data suggest that three monoclonal antibodies against rSl with good activities were ideal materials in the study of early diagnosis of FIPV and the biological function of FIPV in the future.
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Background: Antiviral vaccine is not effective, synthetic antiviral drugs are highly toxic, leading to increased interest in herbal medicines as promising antiviral drugs. Recently, Vipdervir has been developed from medicinal herbs with the aim to support and treat diseases caused by viruses such as H5N1 and SARSCoV- 2. In the present study, we assessed Vipdervir's antiviral activity against H5N1 and SARS-CoV-2. In addition, we also evaluated the acute toxicity and repeated dose toxicity of Vipdervir in mice and rabbits, respectively. Methods: H5N1 inhibitory effect of Vipdervir was assessed using hemagglutination inhibition assay. Vipdervir's SARS-CoV-2 inhibitory effect was evaluated by Plaque Reduction Neutralization assay. Acute and repeated dose oral toxicities of Vipdervir were determined according to OECD 423 and OECD 407 guidelines, respectively. Results: Data show that Vipdervir is effective against both H5N1 and SARSCoV- 2. At concentrations of 3 mg/mL and 5 mg/mL Vipdervir completely inhibits H5N1. At a concentration of 50 g/mL Vipdervir showed an inhibitory effect on SARS-CoV-2. Acute toxicity data revealed that the LD50 of Vipdervir is greater than 35200 mg/kg, b.wt. in mice. Repeated toxicity data indicated that Vipdervir did not induce significant differences in body weight gain, hematology and clinical biochemistry in compared to the control group. The No Observed Adverse Effect Level of Vipdervir is greater than 613.8 mg/kg b.wt./day in rabbits. No delayed toxicity effects of Vipdervir were observed. Conclusion: Vipdervir capsules were found to be antiviral effective and relatively safe in the tested doses and experimental conditions.
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This special issue includes 15 articles that discuss the mutagenic effect of tobacco smoke on male fertility;environmental and occupational exposure of metals and female reproductive health;free radical biology in neurological manifestations;paternal factors in recurrent pregnancy loss;mechanical dependency of the SARS-CoV-2 virus and the renin-angiotensin-aldosterone (RAAS) axis;a perspective review on medicinal plant resources for their antimutagenic potentials;asystematic review and meta-analysis of the impacts of glyphosate on the reproductive hormones;impact of ginseng on neurotoxicity induced by cisplatin in rats.
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This paper describes the pathogenesis and immunology of Macaca mulatta, Macaca fascicularis, ferrets, Syrian golden hamsters (Mesocricetus auratus), mice, cats, mink, pigs and rabbits used as models for SARS-CoV-2 infection.
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Auckland Island, the fifth largest island in New Zealand, is the only island in New Zealand's subantarctic region where introduced mammalian pests remain (pigs, Sus scrofa;mice, Mus musculus;cats, Felis catus). The island has unique biodiversity and is a key site for progressing New Zealand's goal to be free of several introduced predators by 2050. Recent island eradication successes have rekindled interest in eradicating pests from Auckland Island, and for the first time considering all three pests in one project. Over a 3-year period, we tested the feasibility of eradicating pigs, mice and cats by looking at what it would take to succeed, rather than what we could practically deliver with the tools we currently have. We proposed adaptations to current methods and used an evidence-based approach by undertaking large-scale field trials to test uncertainties and emerging technologies in-situ. We gathered data and evaluated proposed methods against five established principles of eradication while considering the logistics and infrastructure requirements of the project. Eradicating pigs, mice and cats from Auckland Island is worthwhile and feasible but dependent on further development of emerging technologies and capabilities for efficient delivery with an acceptable level of risk. Three eradication operations are required with specific sequencing and timing, supported by initial establishment of infrastructure. The project needs a large investment spread over 8 to 10 years to yield permanent and internationally important benefits with low ongoing cost to sustain. The feasibility study exposed the project's scale and was used to inform decision makers, who postponed the work in 2020 in response to the economic impacts of COVID-19. The study focusses future preparations on identified planning issues and dependencies to progress project readiness in anticipation of it being launched when economic conditions allow.
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Rodentia is the most speciose mammalian order, found across the globe, with some species occurring in close proximity to humans. Furthermore, rodents are known hosts for a variety of zoonotic pathogens. Among other animal species, rodents came into focus when the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) spread through human populations across the globe, initially as laboratory animals to study the viral pathogenesis and to test countermeasures. Under experimental conditions, some rodent species including several cricetid species are susceptible to SARS-CoV-2 infection and a few of them can transmit the virus to conspecifics. To investigate whether SARS-CoV-2 is also spreading in wild rodent populations in Germany, we serologically tested samples of free-ranging bank voles (Myodes glareolus, n = 694), common voles (Microtus arvalis, n = 2), house mice (Mus musculus, n = 27), brown or Norway rats (Rattus norvegicus, n = 97) and Apodemus species (n = 8) for antibodies against the virus. The samples were collected from 2020 to 2022 in seven German federal states. All but one sample tested negative by a multispecies ELISA based on the receptor-binding domain (RBD) of SARS-CoV-2. The remaining sample, from a common vole collected in 2021, was within the inconclusive range of the RBD-ELISA, but this result could not be confirmed by a surrogate virus neutralization test as the sample gave a negative result in this test. These results indicate that SARS-CoV-2 has not become highly prevalent in wild rodent populations in Germany.
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This journal issue includes 48 articles that discuss development and validation of a novel quality assessment tool to measure the quality of nutrition information online;longitudinal association between takeaway food environment and secondary school adolescents BMI and body fat percentage;dietary practices, beliefs, and behaviours among adults with inflammatory bowel disease;postpartum depression in Irish mothers and associations with infant feeding practices;the impact of dietary saturated fat replacement with unsaturated fat on the plasma lipidome and cardiometabolic disease risk;ole of brain serotonin in age-related decline in physical activity in mice;ey stakeholder perceptions of food allergies within the airline industry;sleep quality of higher education students during COVID-19 and its association with diet quality and lifestyle behaviours.
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An investigation of coronavirus (CoV) and hepatitis E virus (HEV) in rodents was performed to understand CoV and HEV infection of rodents in Dali City, Yunnan Province. Rodent samples were obtained in the four towns of Dali city through traps from August 2020 to August 2021. A total of 76 rodents belonging to six species and five genera were captured: Rattus tanezumi, Rattus norvegicus, Apodemus chevrieri, Eothenomys miletus, Niviventer fulvescens, and Mus Pahari. Detection of CoV and HEV was performed by nested-PCR. The infection rate of CoV was 40.74% (11/27) and 2.38% (1/42) in R. norvegicus and R. tanezumi, respectively. The infection rate of HEV was 14.81% (4/27) and 2.38% (1/42) in R. norvegicus and R. tanezumi, respectively. Co-infection with CoV and HEV was detected in two R. norvegicus, with a co-infection rate of 7.41% (2/27). A Basic Local Alignment Search Tool (BLAST) search was performed on partial RNA-dependent RNA polymerase (RdRp) sequences of CoV and HEV. Eleven strains from R. norvegicus were a-CoV, and matched best to strain KY370050 from Rattus losea (Fujian, China), with 99.73% to 99.74% nucleotide (nt) sequency identity. One strain was ss-CoV from R. tanezumi, which displayed 98.21% nt sequence identity with strain MT820632 from Bandicota indica (Yunnan, China). Five strains from R. norvegicus were all HEV-C, and showed 95.87% to 96.21% sequence similarity to strain MN450853 from a patient in Hong Kong, China. In conclusion, CoV and HEV infections are present in rodents in Dali City. Because the host animals of the two viruses are closely related to humans, surveillance and investigations of related viruses should be strengthened.
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Since the outbreak of the new crown pneumonia, the new coronavirus (SARSCoV-2) has been mutating continuously, and it has now become prevalent in more than 200 countries. The cumulative number of confirmed cases in the world has exceeded 460 million, and the number of deaths has exceeded 6 million. The rapid mutation of SARS-CoV-2 highlights the importance of preventive and therapeutic drugs, however, effective therapeutic drugs for new coronary pneumonia are still very scarce. It is still the common goal of scientists from all over the world to develop a safe and effective drug for the treatment of new coronary pneumonia that can inhibit the infection of multiple SARS-CoV-2 mutant strains.
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COVID-19, a disease caused by SARS-CoV-2 that produces major symptoms of pneumonia, has been a disaster worldwide. The traceability of SARSCoV- 2 and the discovery of susceptible animal species is crucial to halt viral transmission and explore the mechanism of cross-species transmission. We selected 82 representative ACE2 sequences from the 1000 sequences with the closest homology to the hACE2 protein. All selected ACE2 proteins were subjected to homology modeling. Potential natural and intermediate hosts, as well as animal species susceptible to SARS-CoV-2, were analyzed systematically by calculation of the binding free energy of ACE2 protein to the RBD of SARSCoV- 2. Primates, some wild Felidae, civets, goats, spotted hyenas and golden hamsters are susceptible to SARS-CoV-2 and may be potential intermediate hosts, whereas pangolins, birds and reptiles are unlikely to be intermediate hosts. Mice, rats and guinea pig are not susceptible to SARS-CoV-2. Given their possible susceptibility, non-human primates, goats and golden hamsters could potentially be used as experimental models to examine SARS-CoV-2 infection without transgenesis. Herein, possible candidates for the natural and intermediate hosts of SARS-CoV-2 are suggested, to provide guidance for subsequent studies.
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Objective: The aim of this study is to screen an ideal adjuvant for an inactivated porcine deltacoronavirus(PDCoV) vaccine to induce mucosal immunity and reduce the side effect of the vaccine. We used different mucosal adjuvants to prepare the inactivated PDCoV vaccines. We then used mouse model to evaluate the humoral, cellular and mucosal immune responses induced by the inactivated vaccines via different immunization routes.
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Since the outbreak of COVID-19, the opinion that the aerosol plays a key role in the transmission of SARS-CoV-2 has been controversial. The COVID-19 pandemic has continued interpersonal transmission for more than two years, especially after the emergence of Delta and Omicron variants, making the situation of COVID-19 pandemic more severe. The transmission of SARS-COV-2 variants was significantly accelerated and the time of transmission between generations was significantly shortened. Therefore, it has been questioned to attribute the close-range infection to droplet transmission. The point that the aerosol can also has a close-range transmission and may play a dominant role is neglected under the influence of traditional transmission mode of respiratory infectious diseases. A large number of studies have shown that normal breath, talk and cough could release a large number of respiratory aerosol particles, and the virus particles were mainly tiny particles(=5.0 micro m). The biological activity and infectivity of the droplet nuclei have been questioned in the studies on their physicochemical properties. Animal models of ferrets and hamsters showed that SARS-COV-2 could transmit via aerosol. Therefore, the new evidence for the aerosol transmission of SARS-COV-2 was reviewed in the article so as to provide latest evidence-based evidence for prevention and control of COVID-19.
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This study aims to investigate the protective effect of infected piglets which were immunized with different dose of inactivated porcine epidemic diarrhea virus (PEDV) vaccines. The number of infective virus particles and total virus particles of PEDV with different concentrations were determined, and the mice were immunized with different concentration vaccine prepared as antigen, respectively. The humoral and cellular immune production were determined by ELISA antibody detection method, neutralization test and ELISPOT method. Vaccine with appropriate antigen content was selected to immunize piglets, then the antibody was determined. The relationship between concentrated vaccine and protective effect was studied by challenge experiment. The results showed that, when the antigen dose was equal or greater than 8x106 pfu.mL-1, the inactive vaccine could effectively stimulate mice to produce humoral and cellular immunity. The piglets immunized with 2 mL inactivated PEDV vaccine containing 8x106 pfu.mL-1 antigen could resist diarrhea and continuous viral shedding caused by PEDV challenge. Compared with the total number of virus particles, the number of infectious virus particles was significantly correlated with antibody production (r=0.998 1), and neutralization titer was significantly correlated with piglet protection (r=0.974 7). PEDV inactivated vaccine can provide good immune protection, in which the number of infectious virus particles is the key factor to improve the antibody level. Antibody titer, as an index of humoral immunity, is an important reference for judging immune protection.
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Immunobiotics, a group of probiotics, have the effect of anti-infection by regulating immune function, which can be added in in foods or used to make adjuvants or medicines (biologics). Immunobiotics can stimulate the mucosal immune system of the body, regulate innate and acquired immunity and exert non-specific anti-microbial (bacterial and viral) infection effects through oral, nasal mucosa, sublingual and other routes, but the immune regulation function of immunobiotics is species-specific. Oral administration of Lactobacillus plantarum GUANKE stimulated the increase and maintenance of SARS-CoV-2 neutralization antibodies in mice even 6 months after immunization. When L. plantarum GUANKE was given immediately after SARS-CoV-2 vaccination, the level of SARS-COV-2 specific neutralizing antibody in bronchoalveolar lavage increased by 8 times in mice, which improved the local and systematic cellular immune response to SARS-CoV-2 of mice. Clinical studies have found that immunobiotics have the auxiliary effect in the treatment of COVID-19 by mitigating the symptoms and increase the level of SARS-CoV-2 specific antibody of the patients. It is necessary to conduct research and evaluation for the appropriate guideline of immunobiotics use as erly as possible to provide a new option for the prevention and control of COVID-19.
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In present study, in order to develop a new and effective porcine epidemic diarrhea virus (PEDV)vaccine, three B cell epitopes and the truncated S1 gene of PEDV spike protein were combined and inserted into the immunodominant region of the HBcAg. Then the constructed recombinant plasmid HBcAg-PE was transformed to E. coli BL21 (DE3) for expression. After purification and identification by Western-blot, the expressed recombinant proteins HBPE were injected into BALB/c mice as vaccine antigen with different doses through intramuscular injection and its immune effect were preliminary evaluated. The results showed that the recombinant proteins HBPE was expressed as precipitation form and it could reacted specifically with PEDV-positive serum after purification and renaturation. Besides, the RH could induce anti-PEDV specific antibodies and the related Thl and Th2 cytokines in mice. The above results indicate that the recombinant compound epitope antigen of PEDV was successfully constructed. and its immunogenicity as a new vaccine candidate was evaluated in the mice in this study. The results of this study provided a new idea for the development of PEDV genetic engineering vaccine in the future.
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As a member of the family Picornaviridae, porcine sapelovirus (PSV) is often infected with porcine epidemic diarrhea virus, teschovirus and so on. In recent years, PSV has been isolated from porcine in many provinces of China. It suggests that it is necessary to strengthen the research on PSV. In this study, according to the sequence of PSV HuN2 strain, VP1 gene was inserted into the pGEX-6 P-1 vector, and expressed the recombinant protein. BALB/c mice aged 6-8 weeks were immunized according to the standard procedure. After the third immunization, the mouse orbital blood was collected to identify the antibody level. The highly positive mouse spleen cells were selected for cell fusion. The positive hybridoma cells and two subclones were screened by IFA method, and then a PSV VP1 monoclonal antibody was obtained, named as 33-2 A. The results of IFA showed that PSV could be recognized by 33-2 A MAb, and specific green fluorescence appeared in the cytoplasm;The results of WB and IP showed that PSV infected porcine cell could specifically bind to 33-2 A, and there was a specific band at 32 ku. We also identified the B-cell antigen epitope of 33-2 A, it was at amino acids 40-46 of PSV VP1 protein, and the polypeptide sequence was 40PALTAAE46. The results showed that the monoclonal antibody can react with PSV VP1 protein. The epitope was analyzed with the PSV sequences uploaded in NCBI, 33-2 A antibody can react with most PSV strains and has a certain universal to PSV. This study laid a foundation for the study of the etiology and pathogenesis of PSV.
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[Objective] To identify the B-cell epitope peptide of porcine epidemic diarrhea virus (PEDV) S2 gene by combinative use of bioinformatics software and monoclonal antibody technology. [Method] The B-cell epitope of PEDV S2 gene was screened using CLC Sequence viewer 6.8 software and IEDB online database, and the obtained epitope peptide was synthesized artificially. Female BALB/c mice were immunized with the conjugate of epitope peptide and keyhole hemocyanin (KLH) as antigen. Mice with higher antibody titers were identified by ELISA assay and then received an additional immunization. The spleen of the mice was taken 3 days post immunization to prepare the splenocyte suspension for cell fusion. The cells were grown on HAT selective medium to screen for effective hybridoma cells. The positive clones screened by ELISA assay were then used for expanding culture. Positive hybridoma cells were intraperitoneally injected to mice and ascites were collected. ELISA assay was used to determine the antibody titers in mice ascites and in the supernatants of monoclonal cell strains. The cells with the highest antibody titers was used as cell strain for subsequent use. [Result] The selected B-cell epitope peptide sequence was MQYVYTPTYYML Following immunization with the peptide antigen, the serum antibody titer before cell fusion reached 1:2 000. The ELISA assay of ascites from BALB/c mice and the supernatants from monoclonal cell strain cultures demostrated that the antibody liter reached 1:4 000. [Conclusion] The B-ell epitope of PEDV S2 gene was identified, which may be helpful for the vector construction of a epitope based peptide vaccine against PEDV.