INTRODUCTION:Candida albicans (C. albicans) and Herpes Simplex Virus 2 (HSV-2) are highly prevalent genital pathogens that often coexist, potentially influencing mutual replication and host responses. Building on our recent work employing mono- and co-infections in A-431 epithelial cells, we developed a three-dimensional (3D) in vitro model using inert scaffolds and the presence of a synthetic vaginal fluid (SVF) to better mimic vaginal epithelium. METHODS:A-431 cells were cultured on inert 3D scaffolds, with or without SVF for 5 days, and then infected with C. albicans and/or HSV-2. Cell viability was assessed by LDH release, fungal burden by CFU assay, and viral load by PCR. Histological and immunohistochemical analyses were performed to evaluate epithelial structure, pathogen presence, and IL-6 production. RESULTS:The A-431 cells formed a multilayered epithelium on scaffolds; yet, mature epithelial phenotype markers were not detected. SVF enhanced fungal growth and viral replication during co-infection. C. albicans significantly reduced epithelial viability, whereas HSV-2 showed minimal effects; dual infection caused slightly additive damage. IL-6 was produced both in mono and double infection. CONCLUSION:The 3D scaffold-based model supports polymicrobial infection. Nevertheless, the lack of cell epithelial phenotype highlights the need of further strategies to more closely replicate the in vivo vaginal mucosal environment.
Introduction: Influenza A viruses (IAVs) cause not only seasonal epidemics but also pandemics in humans. The emergence of H5N1 variants resistant to oseltamivir highlights the need to develop new antiviral therapeutic strategies. Accumulated evidence has indicated the potent anti-influenza activity of curcumin (Cur). Nevertheless, the unsatisfactory bioavailability of Cur limits its clinical use. Methods: In the present study, the anti-influenza activity and underlying mechanism of encapsulated Cur in nanoparticle form, referred to as Cur-micelle (Cur-M), were evaluated. Results: Our results demonstrated that, as with native Cur treatment, Cur-M treatment remarkably reduced IAV infection. Interestingly, Cur-M significantly inhibited IAV infectivity post-viral entry, while treatment with Cur alone showed no effect, as demonstrated by differences in plaque formation ability. By monitoring intracellular processing, including the signaling pathway required for IAV propagation and the critical viral replication step, we discovered that viral RNA replication and the activation of Akt signaling were significantly suppressed under Cur-M treatment. Conclusion: This study demonstrates for the first time that Cur-M interferes with intracellular processes required for influenza virus infection, highlighting its potential for further evaluation in both cell-based and in vivo systems.
Introduction: Felid herpesvirus 1 (FeHV-1) is widespread worldwide and is sometimes associated with chronic diseases in cats; therefore, it is clinically important. Vaccination can be used to control FeHV-1 infection. We previously isolated a strain identical to the live attenuated vaccine (LAV) strain F2 from a feline eye with a dendritic ulcer, indicating that the F2 strain may be pathogenic. The origin of the F2 strain that we previously isolated is unknown, and we surmised that the F2 strain may exist in the field. To determine whether the LAV strain F2 exists in the field, we, therefore, performed a genomic analysis of FeHV-1 isolates from cats. Methods: FeHV-1 isolates from cats were genotyped using single-nucleotide variants (SNVs) within two marker genes related to the F2 strain as indicators. Strains with markers were subjected to next-generation sequencing to determine their whole-genome sequence (WGS). Results: Of the nine FeHV-1 isolates, none were found to have two SNVs related to the F2 strain, whereas two isolates were found to have one SNV related to the F2 strain. Because the cats from which these strains were isolated lived together, the isolates were considered to be of the same strain, and we determined the WGS of one strain (strain A-19-5). All coding sequences of strain A-19-5 were identical to those of one of the cloned strains of the Merial vaccine (likely a variant of the F2 strain within the Merial vaccine population). The cat from which the strain was isolated had never received vaccination. Conclusion: The results suggest that a strain identical to a variant of the F2 strain, as found in the FeHV-1-LAV, may exist in the field.
Background: Non-Pharmaceutical Interventions (NPIs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) not only curbed the spread of novel coronavirus (COVID-19) but also affected common respiratory viruses infected by children. Methods: Samples of children diagnosed with respiratory tract infection in Children's Hospital affiliated with Zhejiang University from January 2019 to December 2023 were collected, and ADV, Flu A, Flu B and RSV were detected. Statistical analysis was carried out with R software. Results: From January 2019 to December 2023, a total of 684413 samples were tested, including 369620 males, accounting for 54.01%, and 314793 females, accounting for 45.99%. Among them, there were 213443 positive samples (31.19%), of which 40484 ADV-positive samples (18.97%), 106423 Flu A-positive samples (49.86%), 32379 Flu B-positive samples (15.17%) and 30776 RSV-positive samples (14.42%), 3381 mixed infection samples (1.58%). Among children of different ages in Hangzhou before, during and after COVID-19, the highest total detection rate of respiratory virus was 4-6 years old (accounting for 36.69%), followed by >7 years old (accounting for 35.10%). The distribution in different seasons shows that the number of children infected with respiratory viruses reaches a peak in winter and spring. Compared with 2019 (33.20%) before the COVID-19 epidemic, the total detection rate of common respiratory viruses in children was lower during the COVID-19 pandemic (24.54% in 2020-2022), and it was increased in 2023 while after NPIs were cancelled (accounting for 35.20%). Conclusion: NPI measures can effectively reduce the spread of common respiratory viruses, Lifting of NPIs can lead children to an increase viral infection rate, particularly in Flu A.
Background: West Nile virus (WNV) is an emerging arbovirus for which there is no vaccine nor antiviral treatment. Skin cells are the primary site of WNV replication following transmission by the mosquito vector. In a previous work, strong induction of CXCL10 mRNA expression was observed during in vitro infection of human primary keratinocytes with WNV. Known to be chemoattractant, CXCL10 has also been reported to exhibit antimicrobial peptide properties through direct inhibitory activity against Gram-positive and Gram-negative bacteria. The objective of this work was to investigate the antiviral properties of CXCL10 against WNV. Method and Results: A 24-h time-course infection of keratinocytes in the presence of CXCL10 showed a significant reduction of viral load and infectious titer in the cell culture supernatant. This inhibition of virus replication was observed when the chemokine was added to the cells before or simultaneously with the virus, suggesting pre-fusion action. In contrast, no antiviral effect was observed when CXCL10 was added 3 h postinfection. However, incubation of the virus with CXCL10 did not show any reduction in the infectious titer, ruling out direct damage to the viral particle. In addition, expression of markers of the cells' innate immune response was not modified by adding CXCL10 during the infection. Finally, a reduction in virus attachment to the cells was demonstrated in the presence of CXCL10. Conclusion: Our results showed antiviral activity of CXCL10 against WNV during human keratinocyte infection. Even if additional experiments are required to precisely determine its mechanism of action, CXCL10 could interfere with WNV attachment to the keratinocyte surface.
