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Bioorganic Chemistry Jun 2024The tobacco mosaic virus coat protein (TMV-CP) is indispensable for the virus's replication, movement and transmission, as well as for the host plant's immune system to...
The tobacco mosaic virus coat protein (TMV-CP) is indispensable for the virus's replication, movement and transmission, as well as for the host plant's immune system to recognize it. It constitutes the outermost layer of the virus particle, and serves as an essential component of the virus structure. TMV-CP is essential for initiating and extending viral assembly, playing a crucial role in the self-assembly process of Tobacco Mosaic Virus (TMV). This research employed TMV-CP as a primary target for virtual screening, from which a library of 43,417 compounds was sourced and SH-05 was chosen as the lead compound. Consequently, a series of α-amide phosphate derivatives were designed and synthesized, exhibiting remarkable anti-TMV efficacy. The synthesized compounds were found to be beneficial in treating TMV, with compound 3g displaying a slightly better curative effect than Ningnanmycin (NNM) (EC = 304.54 µg/mL) at an EC of 291.9 µg/mL. Additionally, 3g exhibited comparable inactivation activity (EC = 63.2 µg/mL) to NNM (EC = 67.5 µg/mL) and similar protective activity (EC = 228.9 µg/mL) to NNM (EC = 219.7 µg/mL). Microscale thermal analysis revealed that the binding of 3g (K = 4.5 ± 1.9 µM) to TMV-CP showed the same level with NNM (K = 5.5 ± 2.6 µM). Results from transmission electron microscopy indicated that 3g could disrupt the structure of TMV virus particles. The toxicity prediction indicated that 3g was low toxicity. Molecular docking showed that 3g interacted with TMV-CP through hydrogen bond, attractive charge interaction and π-Cation interaction. This research provided a novel α-amide phosphate structure target TMV-CP, which may help the discovery of new anti-TMV agents in the future.
Topics: Tobacco Mosaic Virus; Antiviral Agents; Phosphates; Structure-Activity Relationship; Molecular Structure; Capsid Proteins; Drug Design; Microbial Sensitivity Tests; Amides; Dose-Response Relationship, Drug; Drug Discovery; Molecular Docking Simulation
PubMed: 38701597
DOI: 10.1016/j.bioorg.2024.107415 -
Science Advances May 2024Tad (tight adherence) pili, part of the type IV pili family, are crucial for mechanosensing, surface adherence, bacteriophage (phage) adsorption, and cell-cycle...
Tad (tight adherence) pili, part of the type IV pili family, are crucial for mechanosensing, surface adherence, bacteriophage (phage) adsorption, and cell-cycle regulation. Unlike other type IV pilins, Tad pilins lack the typical globular β sheet domain responsible for pilus assembly and phage binding. The mechanisms of Tad pilus assembly and its interaction with phage ΦCb5 have been elusive. Using cryo-electron microscopy, we unveiled the Tad pilus assembly mechanism, featuring a unique network of hydrogen bonds at its core. We then identified the Tad pilus binding to the ΦCb5 maturation protein (Mat) through its β region. Notably, the amino terminus of ΦCb5 Mat is exposed outside the capsid and phage/pilus interface, enabling the attachment of fluorescent and affinity tags. These engineered ΦCb5 virions can be efficiently assembled and purified in , maintaining infectivity against , which presents promising applications, including RNA delivery and phage display.
Topics: Caulobacter crescentus; Fimbriae, Bacterial; Cryoelectron Microscopy; Bacteriophages; Fimbriae Proteins; Escherichia coli; Viral Proteins
PubMed: 38701202
DOI: 10.1126/sciadv.adl4450 -
JHEP Reports : Innovation in Hepatology May 2024Peripartum prophylaxis (PP) with tenofovir disoproxil fumarate (TDF) is the standard of care to prevent mother-to-child transmission of chronic hepatitis B (CHB)...
Immediate postpartum cessation of tenofovir did not increase risk of virological or clinical relapse in highly viremic pregnant mothers with chronic hepatitis B infection.
BACKGROUND & AIMS
Peripartum prophylaxis (PP) with tenofovir disoproxil fumarate (TDF) is the standard of care to prevent mother-to-child transmission of chronic hepatitis B (CHB) infection in mothers who are highly viremic. We investigated the maternal and infant outcomes in a large Chinese cohort of TDF-treated CHB pregnant participants.
METHODS
In this prospective study, treatment-naive mothers with CHB and highly viremic (HBV DNA ≥200,000 IU/ml) but without cirrhosis were treated with TDF at 24-28 weeks of pregnancy. In accordance with Chinese CHB guidelines, TDF was stopped at delivery or ≥4 weeks postpartum. Serum HBV DNA and alanine aminotransferase were monitored every 6-8 weeks to determine virological relapse (VR). Infants received standard neonatal immunization, and HBV serology was checked at 7-12 months of age.
RESULTS
Among 330 participants recruited (median age 30, 82.7% HBeAg+, median HBV DNA 7.82 log IU/ml), TDF was stopped at delivery in 66.4% and at ≥4 weeks in 33.6%. VR was observed in 98.3%, among which 11.6% were retreated with TDF. Timing of TDF cessation did not alter the risk of VR (99.0 . 96.9%), clinical relapse (19.5 . 14.3%), or retreatment (12.6 . 10.1%) (all > 0.05). A similar proportion of patients developed alanine aminotransferase flare five times (1.1 . 2.1%; = 0.464) and 10 times (0.5 . 0%; = 0.669) above the upper limit of normal (ULN) in the early withdrawal and late withdrawal groups, respectively. No infants developed HBsAg-positivity.
CONCLUSIONS
PP-TDF and neonatal immunization were highly effective in preventing mother-to-child transmission of HBV in mothers who are highly viremic. Timing of cessation of PP-TDF did not affect the risk of VR or retreatment.
IMPACT AND IMPLICATIONS
In pregnant mothers with chronic hepatitis B infection who are started on peripartum tenofovir to prevent mother-to-child-transmission (MTCT), the optimal timing for antiviral withdrawal during the postpartum period remains unknown. This prospective study demonstrates that stopping tenofovir immediately at delivery, compared with longer treatment duration of tenofovir, did not lead to an increased risk of virological relapse, retreatment, or transmission of the virus to the baby. Shortening the duration of peripartum antiviral prophylaxis from 12 weeks to immediately after delivery can be considered. The immediate withdrawal of peripartum tenofovir, combined with standard neonatal immunization schemes, is 100% effective in preventing MTCT among pregnant mothers with CHB who are highly viremic, with a high rate of vaccine response in infants.
PubMed: 38699531
DOI: 10.1016/j.jhepr.2024.101050 -
Acta Naturae 2024The design of new effective cancer treatment methods is a promising and important research field in translational medicine. Oncolytic viruses can induce immunogenic cell...
The design of new effective cancer treatment methods is a promising and important research field in translational medicine. Oncolytic viruses can induce immunogenic cell death by activating the body's immune system to recognize tumor cells. This work presents the results for optimizing the production of recombinant vesicular stomatitis viruses (rVSVs). To ensure the assembly of viral particles, we developed the HEK293TN-T7 cell line, which stably expresses DNA-dependent RNA polymerase 7 for viral genome transcription, and obtained helper plasmids encoding viral genes under the control of the CAG promoter. The oncolytic activity of the purified virus preparation was assessed in a murine model of B16F10Red melanoma cells expressing a red fluorescent protein. The presented method makes it possible to obtain purified viral preparations with a high titer and oncolytic activity. The amplification of viral particles in a HEK293 suspension culture allows for rapid scalability. Therefore, the developed approach can be used to obtain other recombinant VSV-based oncolytic viruses for tumor immunotherapy.
PubMed: 38698956
DOI: 10.32607/actanaturae.27314 -
Environmental Science & Technology May 2024Sequencing human viruses in wastewater is challenging due to their low abundance compared to the total microbial background. This study compared the impact of four virus...
Sequencing human viruses in wastewater is challenging due to their low abundance compared to the total microbial background. This study compared the impact of four virus concentration/extraction methods (Innovaprep, Nanotrap, Promega, and Solids extraction) on probe-capture enrichment for human viruses followed by sequencing. Different concentration/extraction methods yielded distinct virus profiles. Innovaprep ultrafiltration (following solids removal) had the highest sequencing sensitivity and richness, resulting in the successful assembly of several near-complete human virus genomes. However, it was less sensitive in detecting SARS-CoV-2 by digital polymerase chain reaction (dPCR) compared to Promega and Nanotrap. Across all preparation methods, astroviruses and polyomaviruses were the most highly abundant human viruses, and SARS-CoV-2 was rare. These findings suggest that sequencing success can be increased using methods that reduce nontarget nucleic acids in the extract, though the absolute concentration of total extracted nucleic acid, as indicated by Qubit, and targeted viruses, as indicated by dPCR, may not be directly related to targeted sequencing performance. Further, using broadly targeted sequencing panels may capture viral diversity but risks losing signals for specific low-abundance viruses. Overall, this study highlights the importance of aligning wet lab and bioinformatic methods with specific goals when employing probe-capture enrichment for human virus sequencing from wastewater.
Topics: Wastewater; Humans; Viruses; SARS-CoV-2; Genome, Viral
PubMed: 38690747
DOI: 10.1021/acs.est.4c00580 -
Frontiers in Immunology 2024Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma. The HTLV-1 Tax constitutively activates nuclear factor-κB...
Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma. The HTLV-1 Tax constitutively activates nuclear factor-κB (NF-κB) to promote the survival and transformation of HTLV-1-infected T cells. Despite extensive study of Tax, how Tax interacts with host factors to regulate NF-κB activation and HTLV-1-driven cell proliferation is not entirely clear. Here, we showed that overexpression of Poly (rC)-binding protein 1 (PCBP1) promoted Tax-mediated IκB kinase (IKK)-NF-κB signaling activation, whereas knockdown of PCBP1 attenuated Tax-dependent IKK-NF-κB activation. However, Tax activation of HTLV-1 long terminal repeat was unaffected by PCBP1. Furthermore, depletion of PCBP1 led to apoptosis and reduced proliferation of HTLV-1-transformed cells. Mechanistically, PCBP1 interacted and co-localized with Tax in the cytoplasm, and PCBP1 KH3 domain was indispensable for the interaction between PCBP1 and Tax. Moreover, PCBP1 facilitated the assembly of Tax/IKK complex. Collectively, our results demonstrated that PCBP1 may exert an essential effect in Tax/IKK complex combination and subsequent NF-κB activation, which provides a novel insight into the pathogenetic mechanisms of HTLV-1.
Topics: Humans; Gene Products, tax; NF-kappa B; Human T-lymphotropic virus 1; RNA-Binding Proteins; DNA-Binding Proteins; Heterogeneous-Nuclear Ribonucleoproteins; Signal Transduction; HEK293 Cells; Protein Binding; Cell Proliferation; HTLV-I Infections; Apoptosis; I-kappa B Kinase; Host-Pathogen Interactions
PubMed: 38690287
DOI: 10.3389/fimmu.2024.1375168 -
Frontiers in Immunology 2024It remains unclear whether BPIV3 infection leads to stress granules formation and whether G3BP1 plays a role in this process and in viral replication. This study aims to...
BACKGROUND
It remains unclear whether BPIV3 infection leads to stress granules formation and whether G3BP1 plays a role in this process and in viral replication. This study aims to clarify the association between BPIV3 and stress granules, explore the effect of G3BP1 on BPIV3 replication, and provide significant insights into the mechanisms by which BPIV3 evades the host's antiviral immunity to support its own survival.
METHODS
Here, we use Immunofluorescence staining to observe the effect of BPIV3 infection on the assembly of stress granules. Meanwhile, the expression changes of eIF2α and G3BP1 were determined. Overexpression or siRNA silencing of intracellular G3BP1 levels was examined for its regulatory control of BPIV3 replication.
RESULTS
We identify that the BPIV3 infection elicited phosphorylation of the eIF2α protein. However, it did not induce the assembly of stress granules; rather, it inhibited the formation of stress granules and downregulated the expression of G3BP1. G3BP1 overexpression facilitated the formation of stress granules within cells and hindered viral replication, while G3BP1 knockdown enhanced BPIV3 expression.
CONCLUSION
This study suggest that G3BP1 plays a crucial role in BPIV3 suppressing stress granule formation and viral replication.
Topics: Virus Replication; Animals; Poly-ADP-Ribose Binding Proteins; RNA Recognition Motif Proteins; DNA Helicases; RNA Helicases; Stress Granules; Cattle; Eukaryotic Initiation Factor-2; Respirovirus Infections; Host-Pathogen Interactions; Phosphorylation; Cell Line; Cytoplasmic Granules
PubMed: 38690262
DOI: 10.3389/fimmu.2024.1358036 -
Applied Microbiology and Biotechnology Apr 2024The plant microbes are an integral part of the host and play fundamental roles in plant growth and health. There is evidence indicating that plants have the ability to...
The plant microbes are an integral part of the host and play fundamental roles in plant growth and health. There is evidence indicating that plants have the ability to attract beneficial microorganisms through their roots in order to defend against pathogens. However, the mechanisms of plant microbial community assembly from below- to aboveground compartments under pathogen infection remain unclear. In this study, we investigated the bacterial and fungal communities in bulk soil, rhizosphere soil, root, stem, and leaf of both healthy and infected (Potato virus Y disease, PVY) plants. The results indicated that bacterial and fungal communities showed different recruitment strategies in plant organs. The number and abundance of shared bacterial ASVs between bulk and rhizosphere soils decreased with ascending migration from below- to aboveground compartments, while the number and abundance of fungal ASVs showed no obvious changes. Field type, plant compartments, and PVY infection all affected the diversity and structures of microbial community, with stronger effects observed in the bacterial community than the fungal community. Furthermore, PVY infection, rhizosphere soil pH, and water content (WC) contributed more to the assembly of the bacterial community than the fungal community. The analysis of microbial networks revealed that the bacterial communities were more sensitive to PVY infection than the fungal communities, as evidenced by the lower network stability of the bacterial community, which was characterized by a higher proportion of positive edges. PVY infection further increased the bacterial network stability and decreased the fungal network stability. These findings advance our understanding of how microbes respond to pathogen infections and provide a rationale and theoretical basis for biocontrol technology in promoting sustainable agriculture. KEY POINTS: • Different recruitment strategies between plant bacterial and fungal communities. • Bacterial community was more sensitive to PVY infection than fungal community. • pH and WC drove the microbial community assembly under PVY infection.
Topics: Fungi; Soil Microbiology; Bacteria; Rhizosphere; Plant Diseases; Plant Roots; Microbiota; Plant Leaves; Hydrogen-Ion Concentration; Mycobiome; Plants
PubMed: 38689185
DOI: 10.1007/s00253-024-13150-1 -
Journal of Clinical Microbiology Jun 2024Herpes simplex virus (HSV) infections are one of the most common and stigmatized infections of humankind, affecting more than 4 billion people around the world and more... (Comparative Study)
Comparative Study
Herpes simplex virus (HSV) infections are one of the most common and stigmatized infections of humankind, affecting more than 4 billion people around the world and more than 100 million Americans. Yet, most people do not know their infection status, and antibody testing is not recommended, partly due to poor test performance. Here, we compared the test performance of the Roche Elecsys HSV-1 IgG and HSV-2 IgG, DiaSorin LIAISON HSV-1/2 IgG, and Bio-Rad BioPlex 2200 HSV-1 and HSV-2 IgG assays with the gold-standard HSV western blot in 1,994 persons, including 1,017 persons with PCR or culture-confirmed HSV-1 and/or HSV-2 infection. Across all samples, the Bio-Rad and Roche assays had similar performance metrics with low sensitivity (<85%) but high specificity (>97%) for detecting HSV-1 IgG and both high sensitivity (>97%) and high specificity (>98%) for detecting HSV-2 IgG. The DiaSorin assay had a higher sensitivity (92.1%) but much lower specificity (88.7%) for detecting HSV-1 IgG and comparatively poor sensitivity (94.5%) and specificity (94.2%) for detecting HSV-2 IgG. The DiaSorin assay performed poorly at low-positive index values with 60.9% of DiaSorin HSV-1 results and 20.8% of DiaSorin HSV-2 results with positive index values <3.0 yielding false positive results. Based on an estimated HSV-2 seroprevalence of 12% in the United States, positive predictive values for HSV-2 IgG were 96.1% for Roche, 87.4% for Bio-Rad, and 69.0% for DiaSorin, meaning nearly one of every three positive DiaSorin HSV-2 IgG results would be falsely positive. Further development in HSV antibody diagnostics is needed to provide appropriate patient care.IMPORTANCESerological screening for HSV infections is currently not recommended in part due to the poor performance metrics of widely used commercial HSV-1 and HSV-2 IgG assays. Here, we compare three Food and Drug Administration (FDA)-cleared automated HSV-1 and HSV-2 IgG assays to the gold-standard western blot across nearly 2,000 samples. We find that not all commercially available HSV assays are created equal, with comparably low sensitivities for HSV-1 IgG across platforms and high false positivity rates for DiaSorin on HSV-2 IgG. This study is the first large-scale comparison of performance metrics for the Bio-Rad and Roche assays in over 10 years. Our study confirms that there remains room for improvement in HSV serological diagnostic testing-especially in regard to low sensitivities for HSV-1 IgG detection-and highlights that some previously less-studied assays may have better performance metrics than previously considered typical of commercially available HSV-2 IgG assays.
Topics: Humans; Immunoglobulin G; Herpesvirus 1, Human; Herpesvirus 2, Human; Antibodies, Viral; Sensitivity and Specificity; Herpes Simplex; Male; Female; Adult; Middle Aged; Adolescent; Young Adult; Aged; Automation, Laboratory; Child; Aged, 80 and over; Immunoassay; Child, Preschool
PubMed: 38687020
DOI: 10.1128/jcm.00263-24