Human Metapneumovirus Virus Research Articles

Human metapneumovirus infection of organoid-derived human bronchial epithelium represents cell tropism and cytopathology as observed in in vivo models.

Human metapneumovirus (HMPV) is one of the leading causative agents of respiratory disease in humans, with no treatment or vaccine available yet. The use of primary epithelial cultures that recapitulate the tissue morphology and biochemistry of the human airways could aid in defining more relevant targets to prevent HMPV infection. For this purpose, this study established the first primary organoid-derived bronchial culture model suitable for a broad range of HMPV isolates. These bronchial cultures were assessed for HMPV replication, cellular tropism, cytopathology, and innate immune responses, where the observations were linked to previous in vivo studies with HMPV. This study exposed an important gap in the HMPV field since extensively cell-passaged prototype HMPV B viruses did not replicate in the bronchial cultures, underpinning the need to use recently isolated viruses with a controlled passage history. These results were reproducible in three different donors, supporting this model to be suitable to study HMPV infection.

Development of a novel multi-epitope mRNA vaccine candidate to combat HMPV virus

ABSTRACT Human metapneumovirus (HMPV) is one of the main pathogens causing severe respiratory infections in children, as a common cause of immunodeficiency-related deaths in children and elderly individuals, the prevalence of HMPV has been showing an increasing trend during the last years. However, no vaccines or effective treatment plans are available currently. In this present, based on candidate proteins highly associated with viral virulence and has promising protective potential, we screened for immunodominant cytotoxic T cells, helper T cells, and Linear B-cell epitopes from the most promising candidate Fusion protein, together with G, SH, M, and M2. All epitopes were predicted to have strong antigenicity by Vaxijen and pose no potential toxicity, allergenicity, or hormonology to human proteins by Toxinpred, Allerpred, and Blast analysis, meanwhile, high conservancy is demanded to cover different subtypes. adjuvants β-defensin II and Pam2Cys was attached with EAAAK linkers to improve vaccine’s efficiency. Then, calculation of physicochemical properties proved the protein vaccine as a product can stably exist in the human body. Besides, we assessed the docking between the vaccine and immune receptors to evaluate its ability to stimulate immune responses, and the dynamic simulation further confirmed that the vaccine can tightly bind with immune receptors, which approved that the construction has the potential to induce strong humoral and cellular immune response. Finally, the vaccine was constructed into a multi-epitope mRNA vaccine, the immune simulations suggest that this is a vaccine candidate for controlling HMPV infection.

Prevalence of influenza and viral co-pathogens with severe acute respiratory infection visiting at tertiary care hospital in Nepal

Background: Respiratory infections are one of the major public health problems in Nepal. Data on prevalence and seasonality of respiratory viruses are poorly characterized and hence empirical antimicrobial agents are used in Nepal. The objective of this study was to describe the prevalence and seasonality of influenza and viral co-pathogen in elderly patients with severe acute respiratory infection. Methods and materials: A descriptive cross sectional study was conducted at Central Diagnostic Laboratory and Research Center, Nepal during the year 2017/018. A total of 882 throat & nasopharyngeal swab were collected from patient with severe acute respiratory infection (SARI) according to WHO case definition. Total nucleic acid was extracted using Pure Link viral RNA/DNA mini kit (Invitrogen) and multiplex RT-PCR assays were performed. Results: Of the total 882 specimens; respiratory viruses were found in 556 (63.0%) specimens. Human metapneumovirus 130 (14.7%) was most frequently detected in SARI cases followed by rhinovirus 121 (13.7%), respiratory syncytial virus 37 (4.2%) and enterovirus 36 (4.0%) respectively. The rate of human metapneumovirus 60 (15.7%) co-infection was high than rhinovirus 51 (13.4%), respiratory syncytial virus 13 (3.4%) and enterovirus 12 (3.1%) infection in elderly patients. Co-infection of human metapneumovirus, respiratory syncytial virus, and enterovirus were detected with influenza. Respiratory viruses were detected year-round in Nepal. Incidence of human metapneumovirus virus infection was most commonly detected in summer (July–Aug) and winter (Jan–Feb) season. Conclusion: Respiratory viruses are significantly higher in elderly patient with severe acute respiratory infection. Our findings highlight the importance of real time diagnostic facility for clinical management and minimize the use of antimicrobial agents for respiratory infections in Nepal.

Frequency and Molecular Typing of Human Metapneumovirus in Children with Acute Respiratory Tract Infection in Bojnurd, Northeastern Iran

Background: Acute respiratory infection plays a major role in hospitalization of children worldwide and viruses are one of the most important causative pathogens of acute respiratory tract infections (ARTIs). Human metapneumovirus (hMPV) is a respiratory pathogen responsible for ARTIs in infants and children around the world. The epidemiology of hMPV in the northeast of Iran is poorly described. This study aims to evaluate the prevalence and molecular types of hMPV in children under the age of 12 along with clinical relevance in northeast Iran. Methods: In this cross sectional study, from autumn 2015 to spring 2016 (nine months), 150 nasopharyngeal swabs were collected from children with ARTI and were evaluated for the presence of hMPV by reverse transcriptase-polymerase chain reaction (RT-PCR) technique; after that hMPV typing on positive samples was performed using PCR method. Results: Among the 150 patients that were included the study, 31 (20.6%) were positive for the hMPV genome. We also found that 96.8% (n = 30 cases) of positive cases belonged to genotype A; whereas no B genotype was detected. One of our hMPV isolates was non typable (3.2%). Conclusions: This study, for the first time, reports the existence of Human metapneumovirus virus in children with respiratory symptoms in northeastern Iran. We have also shown that the genotype A is the predominant circulating type among our patients.

Effect of in vitro syncytium formation on the severity of human metapneumovirus disease in a murine model.

Human metapneumovirus (HMPV) is an important cause of acute respiratory tract infections (ARTI) in children, elderly individuals and immunocompromised patients. In vitro, different HMPV strains can induce variable cytopathic effects ranging from large multinucleated syncytia to focal cell rounding. In this study, we investigated the impact of different in vitro phenotypes of two HMPV strains on viral replication and disease severity in a BALB/c mouse model. We first generated two recombinant GFP-expressing HMPV viruses: C-85473, a syncytium-inducing strain (rC-85473) belonging to the A1 subtype and CAN98-75, a focal cell rounding-inducing strain (rCAN98-75) of the B2 subtype. We subsequently exchanged the F genes of both strains to create the chimeric viruses rC-85473_F and rCAN98-75_F. We demonstrated that the F protein was the sole protein responsible for the syncytium phenotype and that viruses carrying a syncytium-inducing F protein replicated to significantly higher titers in vitro. In vivo, however, the virulence and replicative capacity of the different HMPV strains did not appear to be solely dependent on the F gene but also on the viral background, with the strains containing the C-85473 background inducing more weight loss as well as increased lung viral titers, pro-inflammatory cytokines and inflammation than strains containing the CAN98-75 background. In conclusion, the F protein is the main determinant of syncytium formation and replication kinetics in vitro, although it is not the only factor implicated in HMPV disease severity in mice.

Etiological classification of virus in adult community-acquired pneumonia in Yantai

To employ multiplex polymerase chain reaction (PCR) to classify the types of virus in 128 patients of community-acquired pneumonia and analyze the relationship between type of virus, age and seasons. The positive rate of viral pneumonia was 34.4% (44/128). In 44 virus positive patients, the rates of influenza A virus, rhinovirus, adenovirus, parainfluenza type 1, human metapneumovirus virus, influenza B virus, parainfluenza type 2, parainfluenza type 3 and enterovirus were 22.7%(10/44), 15.9%(7/44), 15.9%(7/44), 9.1%(4/44), 9.1%(4/44)6.8%(3/44), 2.3%(1/44), 2.3%(1/44) and 2.3%(1/44)respectively. And other 6(13.6%) patients were at least infected by one virus. The viral pneumonia had a high positive rate in spring and winter. And the age group of 20 to 29 years had a high positive rate. The major pathogen contributing to adult community-acquired pneumonia in Yantai were influenza A virus, rhinovirus and adenovirus. Key words: Community-acquired infections; Noxae

Virus-like particle vaccine induces cross-protection against human metapneumovirus infections in mice

Human metapneumovirus (HMPV) is a paramyxovirus that causes acute respiratory-tract infections in children and adults worldwide. A safe and effective vaccine could decrease the burden of disease associated with this novel pathogen. We engineered HMPV viral-like particles (HMPV-VLPs) derived from retroviral core particles that mimic the properties of the viral surface of two HMPV viruses of either lineage A or B. These VLPs functionally display F and G HMPV surface glycoproteins. When injected in mice, HMPV-VLPs induce strong humoral immune response against both homologous and heterologous strains. Moreover, the induced neutralizing antibodies prevented mortality upon subsequent infection of the lungs with both homologous and heterologous viruses. Upon challenge, viral titers in the lungs of immunized animals were significantly reduced as compared to those of control animals. In conclusion, a HMPV-VLP vaccine that induces cross-protective immunity in mice is a promising approach to prevent HMPV infections.

Progress of human metapneumovirus virus in the respiratory tract infection of children

人类偏肺病毒(hMPV)是一类新近发现的病毒,与儿童,特别是婴幼儿的呼吸道感染关系密切,可以引起上下呼吸道感染.目前研究发现,hMPV感染在世界范围的传播越来越广,且在儿童中感染率有不断上升的趋势,所以对hMPV进行深入研究有利于查明儿童呼吸道感染的病因,对儿童呼吸道感染的防治有重要意义。

Real Time RT-PCR for Quantitation of Human Metapneumovirus Virus from Children with Acute Respiratory Tract Infections

Real Time RT-PCR for Quantitation of Human Metapneumovirus Virus from Children with Acute Respiratory Tract Infections

Rapid human metapneumovirus microneutralization assay based on green fluorescent protein expression

We describe a simple and expedited microneutralization assay for human metapneumovirus virus (HMPV) based on a recombinant HMPV expressing the enhanced green fluorescent protein (rHMPV-GFP). Test serum dilutions were incubated with fixed amounts of rHMPV-GFP and inoculated onto Vero cells, and the growth of non-neutralized rHMPV-GFP was visualized by fluorescent microscopy of living cells. A preliminary titer could be determined following 3 days of incubation. GFP expression was sufficient to be read by an automated scanner after 4–5 days of incubation, which also provided a permanent record. In comparison, the conventional serum neutralization assay requires a longer incubation time plus the additional steps of fixation and staining or immunostaining. rHMPV-GFP-based titers could be determined by the 50% infectivity endpoint method of Reed and Muench [Reed, L.J., Muench, H., 1938. A simple method of estimating fifty per cent endpoint. Am. J. Hyg. 27, 493–497], or by automated scanning and non-linear regression to determine the 50% endpoint of GFP fluorescence. The latter method was two- to three-fold more sensitive. This assay also permits automation and up-scaling, making it suitable for broad HMPV seroepidemiology studies and experiments that require large scale serology, such as vaccine studies.

Human metapneumovirus infections in young and elderly adults.

Human metapneumovirus virus (hMPV) is a newly discovered respiratory pathogen with limited epidemiological data available. Cohorts of young and older adults were prospectively evaluated for hMPV infection during 2 winter seasons. Patients hospitalized for cardiopulmonary conditions during that period were also studied. Overall, 44 (4.5%) of 984 illnesses were associated with hMPV infection, and 9 (4.1%) of 217 asymptomatic subjects were infected. There was a significant difference in rates of hMPV illnesses between years 1 and 2 (7/452 [1.5%] vs. 37/532 [7.0%]; P<.0001). In the second year, 11% of hospitalized patients had evidence of hMPV infection. Infections occurred in all age groups but were most common among young adults. Frail elderly people with hMPV infection frequently sought medical attention. In conclusion, hMPV infection occurs in adults of all ages and may account for a significant portion of persons hospitalized with respiratory infections during some years.