Respiratory syncytial virus (RSV) is an enveloped, negative-sense, single-stranded RNA virus of the Orthopneumovirus  genus of the Pneumoviridae family in the order Mononegavirales. RSV can cause acute upper and lower respiratory tract infections, sometimes with extrapulmonary complications. The disease burden of RSV infection is enormous, mainly affecting infants and older adults aged 75 years or above. Currently, treatment options for RSV are largely supportive. Prevention strategies remain a critical focus, with efforts centered on vaccine development and the use of prophylactic monoclonal antibodies. To date, three RSV vaccines have been approved for active immunization among individuals aged 60 years and above. For children who are not eligible for these vaccines, passive immunization is recommended. A newly approved prophylactic monoclonal antibody, Nirsevimab, which offers enhanced neutralizing activity and an extended half-life, provides exceptional protection for high-risk infants and young children. This review provides a comprehensive and detailed exploration of RSV's virology, immunology, pathogenesis, epidemiology, clinical manifestations, treatment options, and prevention strategies.
Humans ; Respiratory Syncytial Virus Infections/prevention & control* ; Respiratory Syncytial Viruses/pathogenicity* ; Respiratory Syncytial Virus, Human/pathogenicity* ; Antiviral Agents/therapeutic use*

Bacteria/pathogenicity* ; Fungi/pathogenicity* ; Guidelines as Topic ; Humans ; Viruses/pathogenicity*

INTRODUCTION: Respiratory virus (RV) infections have been implicated in acute exacerbation cardiopulmunary conditions. This study aimed to determine the prevalence of RV infections in patients admitted to the cardiology unit with acute decompensated heart failure (ADHF) in a tertiary hospitals in Singapore. MATERIALS AND METHODS: This was a single-centre, prospective observational study. A total of 194 adults (aged >21) admitted to the Singapore General Hospital with ADHF were recruited. A nasopharyngeal swab was taken for multiplex polymerase chain reaction (PCR) detection of influenza virus, rhinovirus, parainfluenza virus (HPIV), human coronavirus (HcoV), adenoviurs, human bocavirus (HboV), human metapneumovirus (hMPV), and respiratory syncytial virus (RSV). RESULTS: Twenty-five (13%) had RVs detected by RV multiplex PCR. There comprised 9 rhinoviruses (36%), 4 influenza A viruses (16%), 3 HPIV (12%), 3 HCoV (12%), 2 adenoviruses (8%), 1 human HBoV (4%), 1 hMPV (4%), and 1 RSV (4%). Symptoms-wise, cough was significantly more common in the PCR-positive group (48% vs 24%, = 0.02). There were no statistically significant differences in laboratory investigations (haemoglobin, leukocytes, platelets, creatine kinase, creatine kinase-muscle/brain, troponin T), and radiology findings between RV PCR-positive and -negative groups. The PCR-positive group did not have increased mortality or length of hospital stay. CONCLUSION This study identified a considerable burden of RVs in our ADHF cohort, and highlights the need for prevention of RVs in this group of patients. We also recognised the difficulty with clinical diagnosis of RVs in ADHF patients.
Adult ; Comorbidity ; Diagnosis, Differential ; Female ; Heart Failure ; epidemiology ; physiopathology ; therapy ; Humans ; Length of Stay ; statistics & numerical data ; Male ; Nasopharynx ; virology ; Outcome Assessment (Health Care) ; Prospective Studies ; Respiratory Tract Infections ; epidemiology ; therapy ; virology ; Singapore ; epidemiology ; Survival Analysis ; Symptom Flare Up ; Viruses ; classification ; isolation & purification ; pathogenicity

In response to viral infection, RIG-I-like RNA helicases detect viral RNA and signal through the mitochondrial adapter protein VISA. VISA activation leads to rapid activation of transcription factors IRF3 and NF-κB, which collaborate to induce transcription of type I interferon (IFN) genes and cellular antiviral response. It has been demonstrated that VISA is activated by forming prion-like aggregates. However, how this process is regulated remains unknown. Here we show that overexpression of HSC71 resulted in potent inhibition of virus-triggered transcription of IFNB1 gene and cellular antiviral response. Consistently, knockdown of HSC71 had opposite effects. HSC71 interacted with VISA, and negatively regulated virus-triggered VISA aggregation. These findings suggest that HSC71 functions as a check against VISA-mediated antiviral response.
Adaptor Proteins, Signal Transducing ; biosynthesis ; chemistry ; genetics ; metabolism ; Cell Aggregation ; genetics ; GPI-Linked Proteins ; metabolism ; Gene Knockdown Techniques ; HEK293 Cells ; HSC70 Heat-Shock Proteins ; genetics ; metabolism ; Heat-Shock Response ; genetics ; Humans ; Interferon Regulatory Factor-3 ; genetics ; metabolism ; Interferon-beta ; genetics ; NF-kappa B ; genetics ; Prions ; metabolism ; Receptors, Retinoic Acid ; metabolism ; Viruses ; drug effects ; metabolism ; pathogenicity

Heparan sulfate (HS) is ubiquitously expressed on the surfaces and in the extracellular matrix of virtually all cell types, making it an ideal receptor for viral infection. Compared with wild-type viruses, cell culture-adapted laboratory strains exhibit more efficient binding to cellular HS receptors. HS-binding viruses are typically cleared faster from the circulation and cause lower viremia than their non-HS-binding counterparts, suggesting that the HS-binding phenotype is a tissue culture adaptation that lowers virus fitness in vivo. However, when inoculated intracranially, efficient cell attachment through HS binding can contribute to viral neurovirulence. The primary aim of this review is to discuss the roles of HS binding in viral pathogenicity, including peripheral virulence and neurovirulence. Understanding how heparan sulfate functions during virus infection in vivo may prove critical for elucidating the molecular mechanism of viral pathogenesis, and may contribute to the development of therapeutics targeting HS.
Heparitin Sulfate ; physiology ; Humans ; Receptors, Virus ; physiology ; Virulence ; Viruses ; pathogenicity

OBJECTIVETo investigate the effects of different factors on the expressions of thymic stromal lymphopoietin (TSLP) in respiratory syncytial virus (RSV)-infected human airway epithelial cell line 16HBE cells.

METHODSRSV amplified by infecting Hep-2 cells was identified for its virulence. 16HBE cells were divided into six groups, namely the control group, RSV group, RSV/anti-TLR3 group, RSV/IFN-gamma group, RSV/IL-4 group and RSV/dexamethasone group with corresponding treatments. Real-time RT-PCR was used to examine the expression of TSLP mRNA in the cells 6 h after RSV infection. Western blotting was used to examine TSLP protein expression in the cells 24 h after the infection.

RESULTSThe expression of TSLP mRNA in 16HBE cells 6 h after RSV infection increased by 1.63-/+0.08 folds as compared to the expression level in the control cells. The expression of TSLP mRNA was significantly decreased in RSV-infected cells treated with anti-TLR3 antibody (P=0.034) and recombinant human IFN-gamma (P<0.001), but increased with the treatment by recombinant human IL-4 (P=0.025). Dexamethasone significantly inhibited the expression of TSLP mRNA in RSV-infected cells (P<0.001). The production of TSLP protein in 16HBE cells increased by 1.9 folds (P<0.001) 24 h after RSV infection, but underwent no significant changes after treatment with anti-TLR3 antibody (P=0.114). Recombinant human IFN-gamma significantly decreased while IL-4 enhanced the expression of TSLP protein in the infected cells (P=0.020 and 0.014, respectively). Dexamethasone significantly inhibited the increment of TSLP protein expression in RSV-infected cells (P<0.001).

CONCLUSIONSRSV infection can enhance the expressions of TSLP in human airway epithelial cells. IFN-gamma, anti-TLR3 and dexamethasone can inhibit the elevation of TSLP expression induced by RSV infection, but IL-4 synergistically enhances its expression.

Bronchi ; cytology ; metabolism ; Cell Line ; Cytokines ; genetics ; metabolism ; Epithelial Cells ; metabolism ; virology ; Humans ; Interferon-gamma ; pharmacology ; Interleukin-4 ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Respiratory Syncytial Virus Infections ; metabolism ; Respiratory Syncytial Viruses ; pathogenicity

Human metapneumovirus (HMPV) shares clinical and epidemiological characteristics with well-known respiratory syncytial virus (RSV). The aim of this study was to investigate the clinical and epidemiological differences between HMPV- and RSV-induced wheezing illnesses. A total of 1,008 nasopharyngeal aspirate specimens was collected from 1,008 pediatric patients hospitalized with acute respiratory tract infection at Inje University Sanggye Paik Hospital from December 2003 to April 2008, and tested for seven common respiratory viruses. Conditions classified as wheezing illness were bronchiolitis, reactive airways disease, and bronchial asthma. HMPV caused a significantly lower proportion of wheezing illness when compared to RSV (48.1% vs. 82.2%, P<0.05). HMPV-induced wheezing illness occurred predominantly in older patients when compared to RSV patients (P<0.001). RSV infections peaked in the fall and winter followed by peaks of HMPV infection in winter and spring. Eosinophil counts were significantly higher (P<0.01) in RSV patients when compared to HMPV patients. These results show that human metapneumovirus patients exhibit several different clinical and epidemiological characteristics, such as higher proportion of wheezing illness, age and seasonal incidence, and eosinophil counts, when compared to RSV patients.
Bronchiolitis/physiopathology/virology ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Korea/epidemiology ; Male ; Metapneumovirus/pathogenicity ; Nasopharynx/virology ; Paramyxoviridae Infections/*epidemiology/*physiopathology/virology ; Respiratory Sounds/*physiopathology ; Respiratory Syncytial Virus Infections/*epidemiology/*physiopathology/virology ; Respiratory Syncytial Viruses/pathogenicity ; Retrospective Studies ; Seasons

Plant Dicer-like (DCL) and Argonaute (AGO) are the key enzymes involved in anti-virus post-transcriptional gene silencing (AV-PTGS). Here we show that AV-PTGS exhibited nucleotide preference by calculating a relative AV-PTGS efficiency on processing viral RNA substrates. In comparison with genome sequences of dicot-infecting Turnip mosaic virus (TuMV) and monocot-infecting Cocksfoot streak virus (CSV), viral-derived small interfering RNAs (vsiRNAs) displayed positive correlations between AV-PTGS efficiency and G+C content (GC%). Further investigations on nucleotide contents revealed that the vsiRNA populations had G-biases. This finding was further supported by our analyses of previously reported vsiRNA populations in diverse plant-virus associations, and AGO associated Arabidopsis endogenous siRNA populations, indicating that plant AGOs operated with G-preference. We further propose a hypothesis that AV-PTGS imposes selection pressure(s) on the evolution of plant viruses. This hypothesis was supported when potyvirus genomes were analysed for evidence of GC elimination, suggesting that plant virus evolution to have low GC% genomes would have a unique function, which is to reduce the host AV-PTGS attack during infections.
Arabidopsis ; enzymology ; genetics ; virology ; Base Composition ; Dactylis ; enzymology ; genetics ; virology ; Genes, Plant ; Genes, Viral ; Models, Genetic ; Mustard Plant ; enzymology ; genetics ; virology ; Plant Diseases ; genetics ; virology ; Plant Proteins ; metabolism ; Plant Viruses ; genetics ; pathogenicity ; Plants ; enzymology ; genetics ; virology ; Potyvirus ; genetics ; pathogenicity ; RNA Interference ; RNA, Plant ; genetics ; RNA, Small Interfering ; chemistry ; genetics ; metabolism ; RNA, Viral ; chemistry ; genetics ; metabolism ; RNA-Induced Silencing Complex ; metabolism ; Ribonuclease III ; metabolism ; Selection, Genetic ; Substrate Specificity

Six diseases have been found after disease surveys on Notopterygium incisum in Gansu province during 2004 to 2007. They were brown spot (Ascochyta levistici), powdery mildew (Erysiphe heraclei), grey spot (Alternaria sp. ; Alternaria burnsii), leaf spot (Septoria dearnessii), angular leaf spot (Pleospora sp.), leaf streak (Phoma sp.), bacterial angular leaf spot and a virus disease. Bacterial angular leaf spot and powdery mildew are the urgent problems waiting to be solved effectively. All these diseases were reported for the first time in China.
Apiaceae ; microbiology ; virology ; Ascomycota ; isolation & purification ; pathogenicity ; Bacteria ; isolation & purification ; pathogenicity ; China ; Plant Diseases ; microbiology ; virology ; Viruses ; isolation & purification ; pathogenicity

Radix Isatidis (Banlangen in Chinese), used to clearing away heat and toxic material, is a traditional Chinese medicinal (TCM) herb. It is frequently used for preventing and treating infectious diseases caused by viruses. To provide scientific basis for the effect of Radix Isatidis on infectious diseases, the traditional effect and new research development on pharmacological activities are summarized in the review. According to the existed problems in the clinical application, the weak links and shortages of quality research and industrialized production of Radix Isatidis are discussed. It could present the new ideas for improving the technology of Radix Isatidis preparation, and promoting the rational use of the preparation in the clinical treatment.
Animals ; Communicable Disease Control ; methods ; Communicable Diseases ; drug therapy ; virology ; Drugs, Chinese Herbal ; therapeutic use ; Humans ; Medicine, Chinese Traditional ; methods ; Viruses ; drug effects ; pathogenicity