Journal of Medical Virology最新文献

MERS is a respiratory disease caused by MERS-CoV. Multiple outbreaks have been reported, and the virus co-circulates with SARS-CoV-2. The long-term (> 6 years) cellular and humoral immune responses to MERS-CoV and their potential cross-reactivity to SARS-CoV-2 and its variants are unknown. We comprehensively investigated long-lasting MERS-CoV-specific cellular and humoral immunity, and its cross-reactivity against SARS-CoV-2 and its variants, in individuals recovered from MERS-CoV infection 1-10 years prior. Two cohorts of MERS-CoV survivors (31 unvaccinated, 38 COVID-19 vaccinated) were assessed for MERS-CoV IgG, memory CD4⁺/CD8⁺ T cells, and neutralizing antibodies against MERS-CoV and SARS-CoV-2 variants. MERS-CoV IgG levels and T cell responses were higher in the 1-5 vs 6-10 year postinfection groups. Vaccinated MERS-CoV survivors had significantly elevated MERS-CoV IgG and neutralization compared to unvaccinated. Both groups demonstrated cross-reactive neutralization of SARS-CoV-2 variants. MERS-CoV survivors vaccinated against SARS-CoV-2 had higher anti-MERS IgG, cellular immunity, and neutralization than unvaccinated survivors. MERS-CoV immune responses can persist for a decade. COVID-19 vaccination boosted humoral and cellular immunity in MERS-CoV survivors, suggesting the benefits of vaccination for this population. These findings have implications for pan-coronavirus vaccine development.

Coronaviruses (CoVs) pose a significant threat to human health, as demonstrated by the COVID-19 pandemic. The large size of the CoV genome (around 30 kb) represents a major obstacle to the development of reverse genetics systems, which are invaluable for basic research and antiviral drug screening. In this study, we established a rapid and convenient method for generating reverse genetic systems for various CoVs using a bacterial artificial chromosome (BAC) vector and Gibson DNA assembly. Using this system, we constructed infectious cDNA clones of coronaviruses from three genera: human coronavirus 229E (HCoV-229E) of the genus Alphacoronavirus, mouse hepatitis virus A59 (MHV-59) of Betacoronavirus, and porcine deltacoronavirus (PDCoV-Haiti) of Deltacoronavirus. Since beta coronaviruses including severe acute respiratory syndrome coronavirus (SARS-CoV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and Middle East respiratory syndrome coronavirus (MERS-CoV) represent major human pathogens, we modified the infectious clone of the beta coronavirus MHV-A59 by replacing its NS5a gene with a fluorescent reporter gene to create a system suitable for high-throughput drug screening. Thus, this study provides a practical and cost-effective approach to developing reverse genetics platforms for CoV research and antiviral drug screening.

Human papillomavirus (HPV) infections rank as the most prevalent sexually transmitted infections globally. The Brazilian Ministry of Health recommends the topical use of 70%-90% trichloroacetic acid (TAA) for treating condyloma acuminata, yet this method suffers from a high recurrence rate of 36% and requires roughly six applications. Topical photodynamic therapy (PDT) has shown effectiveness in targeting subclinical lesions, but it also necessitates multiple sessions for complete lesion clearance. This randomized clinical trial evaluates the efficacy of 80% TAA monotherapy against a combined approach of ultrasonic scalpel excision followed by a single PDT session (US + PDT). The US + PDT group required fewer treatment sessions, exhibited superior cosmetic outcomes, and reported zero lesion recurrence during an 18-month follow-up, in contrast to the TAA group's recurrence rate of 33.3%. Notwithstanding, patient-reported pain during PDT application emerged as a significant barrier, affecting treatment adherence and completion rates. Innovating new PDT protocols could potentially address this challenge, enhancing patient compliance and therapeutic success.

The two most clinically important members of the flavivirus genus, Zika virus (ZIKV) and dengue virus (DENV) pose a significant public health challenge. They cause a range of diseases in humans, from hemorrhagic to neurological manifestations, leading to economic and social burden worldwide. Nevertheless, there are no approved antiviral drugs to treat these infections. Zafirlukast is an orally available Food and Drug Administration (FDA) approved drug for the prophylaxis and treatment of chronic asthma. It is a leukotriene receptor antagonist (LTRA) with high selectivity of the cysteinyl leukotriene-1 receptor (CYSLTR1) that acts as an immune modulator. Thus, we evaluated the antiviral potential of Zafirlukast against ZIKV and DENV in SK-N-SH cells. We showed that Zafirlukast exhibited potent antiviral activity against ZIKV, which could be linked to Zafirlukast's immune blockade of TNF signaling pathways and its downstream signaling pathways such as MAPK and ERK1/2. In addition, our results showed that Zafirlukast also counteracts ZIKV-induced changes in key genes involved in cellular lipid metabolism. Thus, these findings highlight the translational potential of optimizing Zafirlukast as a therapeutic agent for the treatment of ZIKV and DENV.

Multinucleated cells are present in lung tissues of patients infected by SARS-CoV-2. Although the spike protein can cause the fusion of infected cells and ACE2-expressing cells to form syncytia and induce damage, how host cell responses to this damage and the role of DNA damage response (DDR) signals in cell fusion are still unclear. Therefore, we investigated the effect of SARS-CoV-2 spike protein on the fusion of homologous and heterologous cells expressing ACE2 in vitro models, focusing on the protein levels of ATR and ATM, the major kinases responding to DNA damage, and their substrates CHK1 and CHK2. We found that both homologous and heterologous cell fusion activated the ATR-CHK1 and ATM-CHK2 signaling axis and induced the aggregation of γH2AX, 53BP1 and RAD51 in syncytia. In addition, siRNA or inhibitors of ATM and ATR suppressed syncytia formation by decreasing the level of S protein. These results showed the important role of DDR in stabilizing the S protein and in favoring its induction of cell fusion and syncytium formation, suggesting that the virus exploits the host DDR to facilitate its spread among infected cells.

The protective effect of naturally acquired humoral immunity against human papillomavirus (HPV) infection remains unclear. To investigate the role of infection-induced antibodies on HPV detection in heterosexual partners, we used data from 392 unvaccinated couples (females aged 18-25 years attended up to six visits over 2 years; males aged 17-37 years attended up to two visits 4 months apart) enrolled (2005-2011) in Montreal. Genital and blood samples were HPV DNA genotyped and tested for L1 antibody titers of 14 HPV genotypes. Analyses considered female-HPV units (n = 4914 based on 351 couples) and male-HPV units (n = 4214 based on 301 couples); each female and male, respectively, contributed up to 14 observations corresponding to 14 genotypes. Modified Cox and logistic regressions estimated hazard and odds ratios (HR/OR) and 95% confidence intervals (CIs) for genotype-specific HPV detections by partner serostatus (high/low: ≥/< baseline median antibody titers, 392 couples). There were 919 and 231 cumulative HPV detections among female-HPV and male-HPV units, respectively. Risk of HPV detections in females (HR = 1.05, CI: 0.90-1.22) and males (OR = 1.31, CI: 0.97-1.77) was similar between those with partners of high versus low serostatus. Constraining to baseline HPV-negative participants with HPV-positive partners yielded unchanged results. This lack of association suggests that naturally developed HPV antibodies do not protect sexual partners from infection.

An unprecedented global outbreak caused by the monkeypox virus (MPXV) prompted the World Health Organization to declare a public health emergency of international concern on July 23, 2022. Therapeutics and vaccines for MPXV are not widely available, necessitating further studies, particularly in drug repurposing area. To this end, the standardization of in vitro infection systems is essential. The most robust in vitro studies on poxviruses concern the Vaccinia virus, and there are significant gaps in understanding the replicative cycle of MPXV. Herein, we conducted ultrastructural studies using transmission and scanning electron microscopies and 3D reconstruction to describe and elucidate the step-by-step morphogenesis of MPXV. Vero cells, derived from the kidney lineage of Cercopithecus aethiops monkeys, were infected with a strain isolated from an oropharyngeal swab of a patient with suspected Mpox, collected during an observational cohort study conducted between June 12 and August 19, 2022, in Rio de Janeiro, Brazil. Infected Vero cells exhibited several morphological alterations, including cell lysis plaque formation, nuclei with altered chromatin profiles, thickening of the rough endoplasmic reticulum (RER), presence of myelin figures, disorganization of mitochondrial cristae, and the formation of a granular and fibrous matrix (viral factory) surrounded by mitochondria and RER cisternae in a perinuclear space. Viral entry into cells occurred via endocytosis MPXV particles were observed adhering to cytoskeletal filaments, and viral progeny extrusion occurred through exocytosis. This article presents novel data on the morphogenesis of MPXV that have not been previously documented in the literature.