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Scientific Reports Jun 2024We report the first cryoEM structure of the Hendra henipavirus nucleoprotein in complex with RNA, at 3.5 Å resolution, derived from single particle analysis of a...
We report the first cryoEM structure of the Hendra henipavirus nucleoprotein in complex with RNA, at 3.5 Å resolution, derived from single particle analysis of a double homotetradecameric RNA-bound N protein ring assembly exhibiting D14 symmetry. The structure of the HeV N protein adopts the common bi-lobed paramyxoviral N protein fold; the N-terminal and C-terminal globular domains are bisected by an RNA binding cleft containing six RNA nucleotides and are flanked by the N-terminal and C-terminal arms, respectively. In common with other paramyxoviral nucleocapsids, the lateral interface between adjacent N and N protomers involves electrostatic and hydrophobic interactions mediated primarily through the N-terminal arm and globular domains with minor contribution from the C-terminal arm. However, the HeV N multimeric assembly uniquely identifies an additional protomer-protomer contact between the N N-terminus and N C-terminal arm linker. The model presented here broadens the understanding of RNA-bound paramyxoviral nucleocapsid architectures and provides a platform for further insight into the molecular biology of HeV, as well as the development of antiviral interventions.
Topics: Cryoelectron Microscopy; Hendra Virus; Nucleoproteins; Nucleocapsid; Models, Molecular; RNA, Viral; Nucleocapsid Proteins
PubMed: 38890308
DOI: 10.1038/s41598-024-58243-z -
Methods in Molecular Biology (Clifton,... 2024Intracellular pathogens comprise a diverse group of pathogens that all share a required location in a host cell to infect, survive, and replicate. Intracellular location... (Review)
Review
Intracellular pathogens comprise a diverse group of pathogens that all share a required location in a host cell to infect, survive, and replicate. Intracellular location allows pathogens to hide from host immune responses, avoid competition with other pathogens, mediate host cellular functions, replicate safely, and cause infection that is difficult to target with therapeutics. All intracellular pathogens have varying routes of infiltration into host cells and different host cell preferences. For example, bacteria Mycobacterium tuberculosis chooses to invade antigen-presenting cells, which allows them to moderate host antigen presentation to memory cells, whereas rabies virus prefers to invade neurons because they have pre-existing innate immunity protection systems. Regardless of the pathway that each intracellular pathogen follows, all share the capacity to cause disease if they succeed in entering host cells. Here, we give an overview of selected intracellular pathogens and infections they cause, immune responses they induce, and intervention strategies used to treat and control them.
Topics: Humans; Animals; Host-Pathogen Interactions; Mycobacterium tuberculosis; Immunity, Innate; Rabies virus
PubMed: 38888767
DOI: 10.1007/978-1-0716-3890-3_1 -
Scientific Reports Jun 2024Respiratory syncytial virus is the major cause of acute lower respiratory tract infections in young children, causing extensive mortality and morbidity globally, with...
Respiratory syncytial virus is the major cause of acute lower respiratory tract infections in young children, causing extensive mortality and morbidity globally, with limited therapeutic or preventative options. Cathelicidins are innate immune antimicrobial host defence peptides and have antiviral activity against RSV. However, upper respiratory tract cathelicidin expression and the relationship with host and environment factors in early life, are unknown. Infant cohorts were analysed to characterise early life nasal cathelicidin levels, revealing low expression levels in the first week of life, with increased levels at 9 months which are comparable to 2-year-olds and healthy adults. No impact of prematurity on nasal cathelicidin expression was observed, nor were there effects of sex or birth mode, however, nasal cathelicidin expression was lower in the first week-of-life in winter births. Nasal cathelicidin levels were positively associated with specific inflammatory markers and demonstrated to be associated with microbial community composition. Importantly, levels of nasal cathelicidin expression were elevated in infants with mild RSV infection, but, in contrast, were not upregulated in infants hospitalised with severe RSV infection. These data suggest important relationships between nasal cathelicidin, upper airway microbiota, inflammation, and immunity against RSV infection, with interventional potential.
Topics: Cathelicidins; Respiratory Syncytial Virus Infections; Humans; Female; Male; Infant; Infant, Newborn; Respiratory Syncytial Virus, Human; Nasal Mucosa
PubMed: 38886476
DOI: 10.1038/s41598-024-64446-1 -
Cellular and Molecular Life Sciences :... Jun 2024Neutralizing antibodies are considered a correlate of protection against severe human respiratory syncytial virus (HRSV) disease. Currently, HRSV neutralization assays...
Neutralizing antibodies are considered a correlate of protection against severe human respiratory syncytial virus (HRSV) disease. Currently, HRSV neutralization assays are performed on immortalized cell lines like Vero or A549 cells. It is known that assays on these cell lines exclusively detect neutralizing antibodies (nAbs) directed to the fusion (F) protein. For the detection of nAbs directed to the glycoprotein (G), ciliated epithelial cells expressing the cellular receptor CX3CR1 are required, but generation of primary cell cultures is expensive and labor-intensive. Here, we developed a high-throughput neutralization assay based on the interaction between clinically relevant HRSV grown on primary cells with ciliated epithelial cells, and validated this assay using a panel of infant sera. To develop the high-throughput neutralization assay, we established a culture of differentiated apical-out airway organoids (Ap-O AO). CX3CR1 expression was confirmed, and both F- and G-specific monoclonal antibodies neutralized HRSV in the Ap-O AO. In a side-by-side neutralization assay on Vero cells and Ap-O AO, neutralizing antibody levels in sera from 125 infants correlated well, although titers on Ap-O AO were consistently lower. We speculate that these lower titers might be an actual reflection of the neutralizing antibody capacity in vivo. The organoid-based neutralization assay described here holds promise for further characterization of correlates of protection against HRSV disease.
Topics: Humans; Respiratory Syncytial Virus, Human; Antibodies, Neutralizing; Organoids; Animals; Neutralization Tests; Chlorocebus aethiops; Vero Cells; Respiratory Syncytial Virus Infections; CX3C Chemokine Receptor 1; Antibodies, Viral; Viral Fusion Proteins; Infant; Epithelial Cells; Antibodies, Monoclonal
PubMed: 38884678
DOI: 10.1007/s00018-024-05307-y -
BMC Infectious Diseases Jun 2024Respiratory Syncytial Virus (RSV) is a leading cause of acute lower respiratory infection in children worldwide. Understanding its prevalence, variations, and...
INTRODUCTION
Respiratory Syncytial Virus (RSV) is a leading cause of acute lower respiratory infection in children worldwide. Understanding its prevalence, variations, and characteristics is vital, particularly in the context of the COVID-19 pandemic.
OBJECTIVE
The study aimed to investigate the RSV positivity rate, subtype prevalence, age and gender distribution, symptomatology, and co-infection rates during pre-pandemic and pandemic periods.
METHODS
We analyzed data from 15,381 patients tested for RSV between 2017 and 2023.
RESULTS
Our analysis revealed a 7.2% average RSV positivity rate in the pre-pandemic period, with significant fluctuations during the pandemic (1.5% in 2020 to 32.0% in 2021). We observed variations in RSVA and RSVB detection rates. The 0-4 years' age group was consistently the most affected, with a slight male predominance. Fever and cough were common symptoms. Therapeutic interventions, particularly antiviral usage and ventilation requirements, decreased during the pandemic. We also identified variations in co-infection rates with other respiratory viruses.
CONCLUSION
Our study offers critical insights into the impact of the COVID-19 pandemic on RSV prevalence, subtype distribution, patient characteristics, and clinical management. These findings underscore the need for ongoing surveillance and adaptive public health responses.
Topics: Humans; COVID-19; Respiratory Syncytial Virus Infections; India; Male; Female; Infant; Child, Preschool; Coinfection; Child; Prevalence; Respiratory Syncytial Virus, Human; Infant, Newborn; SARS-CoV-2; Adolescent; Adult; Middle Aged; Young Adult; Pandemics
PubMed: 38877428
DOI: 10.1186/s12879-024-09426-6 -
Journal of Zoo and Wildlife Medicine :... Jun 2024Canine distemper virus (CDV) is a well-known RNA virus that affects domestic dogs and all families of wild terrestrial carnivores. Spillover infections from wildlife to...
Canine distemper virus (CDV) is a well-known RNA virus that affects domestic dogs and all families of wild terrestrial carnivores. Spillover infections from wildlife to domestic animals are mitigated by preventive vaccination, but there is limited information on the off-label use of veterinary vaccines for wildlife like raccoons (). Twenty wild-caught raccoons were inoculated with a commercial recombinant DNA canarypox-vectored CDV vaccine, applying a regimen of two serial doses by SC route with an interval of 25-28 days between doses. The CDV serum virus neutralizing antibody (VNA) baseline titers and the postvaccination titers were measured at fixed time points. Forty percent (8/20) of the wild-caught raccoons had CDV VNA titers of 1:8 or greater upon intake, and all but a single individual were juvenile animals. Approximately one month following the first vaccine dose, 8% (1/12) of raccoons seronegative at baseline had serum CDV VNA titers of 1:24 or greater. Approximately one month following the booster vaccine dose, 67% (8/12) of raccoons seronegative at baseline had serum CDV VNA titers of 1:24 or greater. Among raccoons with CDV VNA titers greater than or equal to 1:8 at baseline, 13% (1/8) demonstrated a fourfold or greater rise in titer one month after the first vaccine dose, whereas 38% (3/8) reached the same threshold one month after the booster dose. The presence of naturally acquired CDV VNA in juvenile raccoons at the time of vaccination may have interfered with the humoral VNA response. A regimen of at least two serially administered SC vaccine doses may be immunogenic for raccoons, but further investigation of alternative routes, regimens, and CDV vaccine products is also warranted for this species.
Topics: Animals; Raccoons; Distemper; Distemper Virus, Canine; Viral Vaccines; Antibodies, Viral; Male; Female; Animals, Wild; Vaccination
PubMed: 38875203
DOI: 10.1638/2023-0078 -
Journal of Zoo and Wildlife Medicine :... Jun 2024are responsible for proventricular dilatation disease (PDD) in psittacines. This study aimed to determine the occurrence and factors associated with infection in...
are responsible for proventricular dilatation disease (PDD) in psittacines. This study aimed to determine the occurrence and factors associated with infection in psittacines kept in captivity in a state in the southern region of Brazil. A cross-sectional study was carried out with 192 birds from two facilities (A and B) in 2019, using choanal, esophageal, and cloacal swabs and feathers, totaling 768 samples subjected to reverse-transcription polymerase chain reaction (RT-PCR), for the matrix (M) protein gene with a final product of 350 base pairs (bp). Genetic sequencing of three positive samples was performed by the Sanger method. In the study, the overall virus occurrence was 35.9% (69/192), with 40.4% (42/104) in Facility A and 30.7% (27/88) in Facility B. Sequencing analysis of the samples revealed the presence of (PaBV-2) in both facilities. Swab samples from the choanal (40/69), esophageal (30/69), cloacal (35/69), and feather (15/69) tested positive, facilitating the molecular diagnosis of . The results indicated that there is no single ideal sample type for antemortem molecular diagnosis of this virus. Simultaneously testing all four samples at the same time point yielded more diagnoses than testing any single sample among the four. Most of the 29 sampled psittacine species were native, and 46.9% of the birds (90/192) consisted of endangered species. Among the psittacines that tested positive, 88.4% (61/69) were clinically healthy, and 8.7% (6/69) exhibited clinical or behavioral signs, including behavioral changes, alterations in feathering, and changes in body score at the time of collection. This study showcases the application of minimally invasive sampling for diagnosing , enabling sample collection when the birds are restrained for clinical evaluation. This approach facilitates a prompt and effective antemortem diagnosis, thereby serving as an efficient screening method for parrots kept in captivity.
Topics: Animals; Brazil; Bird Diseases; Bornaviridae; Mononegavirales Infections; Cross-Sectional Studies; Animals, Zoo; Parrots; Psittaciformes
PubMed: 38875191
DOI: 10.1638/2023-0051 -
Journal of Medical Virology Jun 2024Viruses in human semen may be sexually transmitted via free and cell-mediated viral infection. The potential effects of semen on the infection and sexual transmission of...
Viruses in human semen may be sexually transmitted via free and cell-mediated viral infection. The potential effects of semen on the infection and sexual transmission of most viruses in semen remain largely unclear. The present study elucidated the inhibitory effects of human seminal plasma (SP) on Jurkat cell (JC)-mediated mumps virus (MuV) infection. We demonstrated that MuV efficiently infected JCs and that the JCs infected by MuV (JC-MuV) mediated MuV infection of HeLa cells. Remarkably, SP was highly cytotoxic to JCs and inhibited JC-MuV infection of HeLa cells. The cytotoxic factor possessed a molecular weight of less than 3 kDa, whereas that of the viricidal factor was over 100 kDa. The cooperation of cytotoxic and viricidal factors was required for the SP inhibition of JC-MuV infection, and prostatic fluid (PF) was responsible for both the cytotoxic and viricidal effects of SP. The cytotoxic effects we observed were resistant to the treatment of PF with boiling water, proteinase K, RNase A, and DNase I. Our results provide novel insights into the antiviral properties of SP, which may limit cell-mediated sexual viral transmission.
Topics: Humans; Mumps virus; Semen; Male; HeLa Cells; Lymphocytes; Jurkat Cells; Cell Survival; Molecular Weight
PubMed: 38874268
DOI: 10.1002/jmv.29733 -
Journal of Medical Virology Jun 2024Ebolavirus disease (EVD) is an often-lethal disease caused by the genus Ebolavirus (EBOV). Although vaccines are being developed and recently used, outbreak control...
Ebolavirus disease (EVD) is an often-lethal disease caused by the genus Ebolavirus (EBOV). Although vaccines are being developed and recently used, outbreak control still relies on a combination of various factors, including rapid identification of EVD cases. This allows rapid patient isolation and control measure implementation. Ebolavirus diagnosis is performed in treatment centers or reference laboratories, which usually takes a few hours to days to confirm the outbreak or deliver a clear result. A fast and field-deployable molecular detection method, such as the isothermal amplification recombinase-aided amplification (RAA), could significantly reduce sample-to-result time. In this study, a RT-RAA assay was evaluated for EBOV detection. Various primer and probe combinations were screened; analytical sensitivity and cross-specificity were tested. A total of 40 archived samples from the 2014 to 2016 Ebola outbreak in West Africa were tested with both the reference method real-time RT-PCR and the established RT-RAA assay. The assay could detect down to 22.6 molecular copies per microliter. No other pathogens were detected with the Ebolavirus RT-RAA assay. Testing 40 samples yield clinical sensitivity and specificity of 100% each. This rapid isothermal RT-RAA assay can replace the previous RT-RPA and continue to offer rapid EBOV diagnostics.
Topics: Ebolavirus; Hemorrhagic Fever, Ebola; Nucleic Acid Amplification Techniques; Humans; Sensitivity and Specificity; Recombinases; Molecular Diagnostic Techniques; Africa, Western; Disease Outbreaks; RNA, Viral; DNA Primers
PubMed: 38874258
DOI: 10.1002/jmv.29744 -
Journal of Medical Virology Jun 2024This study aimed to determine the timing patterns of the initial respiratory syncytial virus (RSV) infection and to identify the factors influencing disease severity in...
This study aimed to determine the timing patterns of the initial respiratory syncytial virus (RSV) infection and to identify the factors influencing disease severity in infants of varying health status. A retrospective study was conducted at the Affiliated Children's Hospital of Chongqing Medical University from 2012 to 2022. The timing of the first RSV infection was estimated in infants with differing health status using correlation analysis, considering their birth time. Logistic regression was utilized to identify factors influencing severe RSV infection in these infants. RSV detection primarily occurred in the winter and spring. Epidemic season and peak timing of RSV were not significantly affected by health status or the COVID-19 pandemic. A strong positive correlation was observed between the age at RSV infection and the interval from birth to the RSV peak season. Infants born during the RSV epidemic season exhibited a higher likelihood of infection within the first 2 months postbirth. In contrast, those born outside the RSV epidemic season were more susceptible to infection during the subsequent peak. Notably, infants with pre-existing health conditions contracted RSV at an earlier age compared to their healthy counterparts. Among healthy infants, severe RSV infection was associated with sex, age, and timing of infection. For infants with underlying conditions, severe RSV infection was primarily related to age and timing of infection. The initial timing of RSV infection in infants varied depending on their health status. Young age and infection timing during the RSV epidemic season were significant risk factors for severe RSV infection. These findings provide a theoretical basis for optimizing immunization strategies for infants with diverse health conditions.
Topics: Humans; Respiratory Syncytial Virus Infections; Infant; Male; Female; Retrospective Studies; Seasons; Severity of Illness Index; Infant, Newborn; Respiratory Syncytial Virus, Human; Hospitalization; Risk Factors; COVID-19; Health Status; China; Time Factors
PubMed: 38873911
DOI: 10.1002/jmv.29719