Journal of Medical Virology最新文献

A large spectrum of viruses can infect the male reproductive system (MRS). Although the MRS adopts the local antiviral defense, it has also been considered as a potential viral reservoir. We hypothesize that tissue-specific cells may eliminate invading viruses and harbor viral replication in the MRS. We herein aimed to identify viral eliminators and potential reservoirs in the MRS using mumps virus (MuV) and mouse models. Primary cells, mainly consisting of epithelial cells, stromal cells, and macrophages, were isolated from the epididymis, seminal vesicle, and prostate of mice. MuV infection and replication were analyzed by determining MuV nucleoprotein (MuV-NP) in the primary cells. We demonstrated that a subset of resident macrophages efficiently took up and eliminated MuV, which should be involved in the antiviral defense in the MRS. However, a small subset of epithelial and stromal cells in these organs harbored MuV replication, and these cells could be viral reservoirs. Furthermore, interferon-β (IFN-β) inhibited MuV replication in MuV-replicating cells, suggesting that IFN-β administration may limit viral reservoirs. The results of the present study provide novel insights into the antiviral defense and viral reservoirs in the MRS, which can aid in the development of preventive and therapeutic approaches for viral infection of the MRS.

To examine the relationship between autoantibodies, inflammatory cytokines, and coagulation abnormalities in patients with severe fever with thrombocytopenia syndrome (SFTS) and assess their potential as prognostic markers. A total of 105 SFTS patients and 85 healthy controls (HCs) were included. Serum levels of antinuclear antibodies (ANAs), anti-neutrophil cytoplasmic antibodies (ANCAs), anti-endothelial cell antibodies (AECAs), antiphospholipid antibodies (aPLs), as well as inflammatory cytokines and chemokines were measured to evaluate their correlation with prognosis. AECA positivity was found in over 50% of SFTS patients, with higher titers correlating with poor prognosis. AECA levels were associated with hypertension, consciousness disorder, and advanced age. Elevated aPLs were observed and associated with coagulation dysfunction, including prolonged activated partial thromboplastin time (APTT) and thrombin time (TT). Serum levels of inflammatory cytokines and chemokines (IL-1β, IL-6, IL-8, CCL2, and CXCL10) were significantly higher in SFTS patients compared to HCs. Elevated AECA and aPLs, along with a dysregulated cytokine/chemokine profile, were identified as significant prognostic indicators in SFTS, offering potential biomarkers for disease severity. Further research is needed to explore the mechanistic roles of these immune responses and to develop targeted therapies.

Mayaro virus (MAYV) is an arthritogenic arbovirus that causes a debilitating illness that can progress to a chronic rheumatic disease characterized by persistent viral replication in macrophages within joint tissues. Here, we report that MAYV-infected macrophages release decondensed DNA traps (DNA extracellular traps, DETs) through a mechanism driven by the production of reactive oxygen species and peptidyl arginine deiminase activation, resembling the classical mechanism of pathogen clearance by activated neutrophils. Unlike traditional pathogen clearance observed for NETs released by neutrophils, MAYV-induced DETs did not inactivate the virus. Instead, DET-ensnared viruses are internalized by neighboring uninfected macrophages, increasing the number of infected cells. Collectively, these findings suggest that MAYV-containing DETs act as a “Trojan horse” that facilitates viral dissemination within inflamed tissues, connecting macrophage-mediated inflammatory response to viral persistence in the articular tissue in chronic MAYV disease.

Dengue is a potentially fatal disease caused by any of the four serotypes of dengue virus complex (DENV1-4). Domain III (DIII) of the envelope protein mediates early virus:cell interactions and is target of potent neutralizing antibodies. Little data is available on the dynamic of IgG subclasses in anti-DIII response elicited during viral infection. Fifty-eight human sera were used to characterize the IgG subclass profile of the anti-DIII antibody response in terms of abundance and serotype-specificity. Immunodominant epitopes were also determined using 70 Ala-mutants of a recombinant DIII protein that spans residues with more than 15% of the exposed area in the virion. IgG1 and IgG3 were found as the subclasses that react to control primary infections while a significant response was detected for all IgG subclasses in response to secondary infections. Anti-DIII IgG1 exhibits a distinctive pattern of serotype-specificity with respect to the other IgG subclasses in the recognition of recombinant DIII proteins corresponding to the four DENV serotypes. The dominant epitope of IgG1 is located in the FG-loop, which is characterized by high variability in its amino acid sequence. In contrast, the dominant epitopes of IgG2, IgG3, and IgG4 were defined as regions enriched in complex- and subcomplex conserved residues such as the A-strand and the AB-loop of DIII. IgG1 plays a prominent role in neutralizing circulating DENV during infection. A balanced and timely response of the different IgG subclasses is critical in the evolution of dengue disease.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus (SFTSV). Shandong province is one of the epidemic regions with high incidence rate of SFTS. To investigate phylogenetical and genetic evolution characteristics of SFTSV in Shandong province, we isolated SFTSV from suspected patients between April 2023 and October 2024, and then whole SFTSV genomes were amplified and sequenced in this study. A total of 25 new strains were analyzed together 56 strains submitted in Genbank from Shandong province. Phylogenetical and genetic analyses of the data set revealed that four genotypes were co-circulating in Shandong province. C3 genotype was the most common genotype in each year with lower genetic divergence. 298 amino acid substitutions were detected in the four proteins of SFTSV, but only two substitutions (Arg624Lys and Arg962Ser) had been proven to have potential impacts on biological functions. In addition, one reassortment strain (C3/C4/C4 for L, M and S segments) and three recombinant strains were identified. Analysis of selection pressure at the level of amino acid substitutions indicated genes within the four ORFs of SFTSV were all subjected to negative selection. In conclusion, the genetic characteristics and evolutionary mechanism of SFTSV was complex in Shandong province. It is necessary to conduct continuous surveillance to grasp the genetic evolution patterns, and to discover novel prevalent variants in a timely manner.