scholarly journals Development of surface engineered antigenic exosomes as vaccines for respiratory syncytial virus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suyeon Hong ◽  
Shaobo Ruan ◽  
Zachary Greenberg ◽  
Mei He ◽  
Jodi L. McGill
Keyword(s):  
Respiratory Syncytial Virus ◽  
Immune Responses ◽  
Ex Vivo ◽  
Subcutaneous Administration ◽  
Antigenic Peptides ◽  
Vaccine Platform ◽  
Mhc I ◽  
Syncytial Virus ◽  
Tract Infections

AbstractRespiratory syncytial virus (RSV) is one of the main pathogens associated with lower respiratory tract infections in infants and young children worldwide. Exosomes secreted by antigen presenting cells (APCs) can elicit immune responses by carrying major histocompatibility complex (MHC) class I molecules complexed with antigenic peptides and other co-stimulating factors. Therefore, we developed novel immunomagnetic nanographene particles to sequentially isolate, surface engineer, and release intact dendritic cell (DC) exosomes for use as a potential vaccine platform against RSV. The H-2Db-restricted, immunodominant peptides from RSV (M187–195 and NS161–75) were introduced to MHC-I on DC-derived exosomes to express peptide/MHC-I (pMHC-I) complexes. A mouse model of RSV infection was used to define the immunogenicity of surface engineered exosomes for activating virus-specific immune responses. Ex vivo assays demonstrated that engineered exosomes carrying RSV-specific peptides can elicit interferon-gamma (IFN-γ) production by virus-specific CD8+ T cells isolated from RSV-infected C57BL/6 mice. In vivo assays demonstrated that subcutaneous administration of both M187–195 and NS161–75 engineered exosomes to mice, with or without additional adjuvant, appeared safe and well tolerated, however, did not prime antigen-specific CD8+ T cell responses. Surface engineered exosomes are immunogenic and promising for further development as a vaccine platform.

scholarly journals Loss of versican and production of hyaluronan in lung epithelial cells are associated with airway inflammation during RSV infection

2020 ◽  
pp. jbc.RA120.016196
Author(s):  
Gerald G. Kellar ◽  
Kaitlyn A. Barrow ◽  
Lucille M. Rich ◽  
Jason S. Debley ◽  
Thomas N. Wight ◽  
...  
Keyword(s):  
Airway Inflammation ◽  
Ex Vivo ◽  
Lung Epithelial Cells ◽  
In Vivo Studies ◽  
Critical Feature ◽  
Human Lung Fibroblast ◽  
Rsv Infection ◽  
Syncytial Virus ◽  
Tract Infections

Airway inflammation is a critical feature of lower respiratory tract infections caused by viruses such as respiratory syncytial virus (RSV). A growing body of literature has demonstrated the importance of extracellular matrix (ECM) changes such as the accumulation of hyaluronan (HA) and versican in the subepithelial space in promoting airway inflammation; however, whether these factors contribute to airway inflammation during RSV infection remains unknown. To test the hypothesis that RSV infection promotes inflammation via altered HA and versican production, we studied an ex vivo human bronchial epithelial cell (BEC)/human lung fibroblast (HLF) co-culture model. RSV infection of BEC/HLF co-cultures led to decreased hyaluronidase expression by HLFs, increased accumulation of HA, and enhanced adhesion of U937 cells as would be expected with increased HA. HLF production of versican was not altered following RSV infection; however, BEC production of versican was significantly downregulated following RSV infection. In vivo studies with epithelial-specific versican-deficient mice [SPC-Cre(+) Vcan-/-] demonstrated that RSV infection led to increased HA accumulation compared to control mice which also coincided with decreased hyaluronidase expression in the lung. SPC-Cre(+) Vcan-/- mice demonstrated enhanced recruitment of monocytes and neutrophils in bronchoalveolar lavage fluid and increased neutrophils in the lung compared to SPC-Cre(-) RSV-infected littermates. Taken together, these data demonstrate that altered ECM accumulation of HA occurs following RSV infection and may contribute to airway inflammation. Additionally, loss of epithelial expression of versican promotes airway inflammation during RSV infection further demonstrating that versican’s role in inflammatory regulation is complex and dependent on the microenvironment.

scholarly journals Pharmacokinetics-Pharmacodynamics of a Respiratory Syncytial Virus Fusion Inhibitor in the Cotton Rat Model

2010 ◽  
Vol 54 (11) ◽  
pp. 4534-4539 ◽  
Author(s):  
Marie-Claude Rouan ◽  
Tom Gevers ◽  
Dirk Roymans ◽  
Loeckie de Zwart ◽  
David Nauwelaers ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Subcutaneous Administration ◽  
Fusion Inhibitor ◽  
Elderly Persons ◽  
Dependent Manner ◽  
Viral Titer ◽  
Plasma Drug ◽  
Cotton Rat ◽  
Syncytial Virus ◽  
Tract Infections

ABSTRACT Human respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in infants, young children, elderly persons, and severely immunocompromised patients. Effective postinfection treatments are not widely available, and currently there is no approved vaccine. TMC353121 is a potent RSV fusion inhibitor in vitro, and its ability to reduce viral loads in vivo was demonstrated in cotton rats following prophylactic intravenous administration. Here, the pharmacokinetics of TMC353121 in the cotton rat, which is semipermissive for RSV replication, were further explored to build a pharmacokinetic-pharmacodynamic (PK-PD) model and to estimate the plasma drug levels needed for significant antiviral efficacy. TMC353121 reduced the viral titers in bronchoalveolar lavage fluid in a dose-dependent manner after a single subcutaneous administration and intranasal RSV inoculation 24 h after compound administration. The viral titer reduction and plasma TMC353121 concentration at the time of RSV inoculation were well described using a simple E max model with a maximal viral titer reduction (E max) of 1.5 log10. The plasma drug level required to achieve 50% of the E max (200 ng/ml) was much higher than the 50% inhibitory concentration observed in vitro in HeLaM cells (0.07 ng/ml). In conclusion, this simple PK-PD approach may be useful in predicting efficacious exposure levels for future RSV inhibitors.

scholarly journals Immunoproteomic Lessons for Human Respiratory Syncytial Virus Vaccine Design

2019 ◽  
Vol 8 (4) ◽  
pp. 486
Author(s):  
López ◽  
Barriga ◽  
Lorente ◽  
Mir
Keyword(s):  
Respiratory Syncytial Virus ◽  
Immune Responses ◽  
Antigen Processing ◽  
Hla Class I ◽  
Human Respiratory Syncytial Virus ◽  
Class I ◽  
Antigenic Peptides ◽  
Cellular Immune Responses ◽  
Syncytial Virus ◽  
Cellular Immune

Accurate antiviral humoral and cellular immune responses require prior recognition of antigenic peptides presented by human leukocyte antigen (HLA) class I and II molecules on the surface of antigen-presenting cells. Both the helper and the cytotoxic immune responses are critical for the control and the clearance of human respiratory syncytial virus (HRSV) infection, which is a significant cause of morbidity and mortality in infected pediatric, immunocompromised and elderly populations. In this article we review the immunoproteomics studies which have defined the general antigen processing and presentation rules that determine both the immunoprevalence and the immunodominance of the cellular immune response to HRSV. Mass spectrometry and functional analyses have shown that the HLA class I and II cellular immune responses against HRSV are mainly focused on three viral proteins: fusion, matrix, and nucleoprotein. Thus, these studies have important implications for vaccine development against this virus, since a vaccine construct including these three relevant HRSV proteins could efficiently stimulate the major components of the adaptive immune system: humoral, helper, and cytotoxic effector immune responses.

Role of human metapneumovirus and respiratory syncytial virus in asthma exacerbations: where are we now?

2017 ◽  
Vol 131 (14) ◽  
pp. 1713-1721 ◽  
Author(s):  
Penny A. Rudd ◽  
Belinda J. Thomas ◽  
Ali Zaid ◽  
Martin MacDonald ◽  
Keiko Kan-o ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Animal Models ◽  
Immune Responses ◽  
Human Metapneumovirus ◽  
Innate Immune Responses ◽  
Adaptive Responses ◽  
Hmpv Infection ◽  
Acute Exacerbations ◽  
Syncytial Virus

Since its discovery in 2001, human metapneumovirus (hMPV) has been identified as an important cause of respiratory tract infection in young children, second only to the closely related respiratory syncytial virus (RSV). Clinical evidence suggests that hMPV is associated with acute exacerbations of asthma in both children and adults, and may play a role in initiating asthma development in children. Animal models have demonstrated that airway hyperresponsiveness (AHR) and inflammation are triggered following hMPV infection, and hMPV is able to persist in vivo by inhibiting innate immune responses and causing aberrant adaptive responses. In this review, we discuss the prevalence of hMPV infection in pediatric and adult populations and its potential role in asthma exacerbation. We also review recent advances made in animal models to determine immune responses following hMPV infection, and compare to what is known about RSV.

scholarly journals TMEM16A/ANO1 calcium-activated chloride channel as a novel target for the treatment of human respiratory syncytial virus infection

Thorax ◽  
2020 ◽  
Vol 76 (1) ◽  
pp. 64-72
Author(s):  
Hayley Pearson ◽  
Eleanor J A A Todd ◽  
Mareike Ahrends ◽  
Samantha E Hover ◽  
Adrian Whitehouse ◽  
...  
Keyword(s):  
Life Cycle ◽  
Respiratory Syncytial Virus ◽  
Human Lung ◽  
Ex Vivo ◽  
Specific Inhibitor ◽  
Human Respiratory Syncytial Virus ◽  
Respiratory Pathogen ◽  
Human Lung Epithelial Cell ◽  
Syncytial Virus ◽  
Tract Infections

IntroductionHuman respiratory syncytial virus (HRSV) is a common cause of respiratory tract infections (RTIs) globally and is one of the most fatal infectious diseases for infants in developing countries. Of those infected, 25%–40% aged ≤1 year develop severe lower RTIs leading to pneumonia and bronchiolitis, with ~10% requiring hospitalisation. Evidence also suggests that HRSV infection early in life is a major cause of adult asthma. There is no HRSV vaccine, and the only clinically approved treatment is immunoprophylaxis that is expensive and only moderately effective. New anti-HRSV therapeutic strategies are therefore urgently required.MethodsIt is now established that viruses require cellular ion channel functionality to infect cells. Here, we infected human lung epithelial cell lines and ex vivo human lung slices with HRSV in the presence of a defined panel of chloride (Cl−) channel modulators to investigate their role during the HRSV life-cycle.ResultsWe demonstrate the requirement for TMEM16A, a calcium-activated Cl− channel, for HRSV infection. Time-of-addition assays revealed that the TMEM16A blockers inhibit HRSV at a postentry stage of the virus life-cycle, showing activity as a postexposure prophylaxis. Another important negative-sense RNA respiratory pathogen influenza virus was also inhibited by the TMEM16A-specific inhibitor T16Ainh-A01.DiscussionThese findings reveal TMEM16A as an exciting target for future host-directed antiviral therapeutics.

scholarly journals Alveolar Macrophages Can Control Respiratory Syncytial Virus Infection in the Absence of Type I Interferons

2016 ◽  
Vol 8 (5) ◽  
pp. 452-463 ◽  
Author(s):  
Spyridon Makris ◽  
Monika Bajorek ◽  
Fiona J. Culley ◽  
Michelle Goritzka ◽  
Cecilia Johansson
Keyword(s):  
Respiratory Syncytial Virus ◽  
Viral Replication ◽  
Alveolar Macrophages ◽  
Ex Vivo ◽  
Type I Interferons ◽  
Type I ◽  
Proinflammatory Mediators ◽  
Rsv Infection ◽  
Syncytial Virus ◽  
Tract Infections

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infections. Immunity to RSV is initiated upon detection of the virus by pattern recognition receptors, such as RIG-I-like receptors. RIG-I-like receptors signal via MAVS to induce the synthesis of proinflammatory mediators, including type I interferons (IFNs), which trigger and shape antiviral responses and protect cells from infection. Alveolar macrophages (AMs) are amongst the first cells to encounter invading viruses and the ones producing type I IFNs. However, it is unclear whether IFNs act to prevent AMs from serving as vehicles for viral replication. In this study, primary AMs from MAVS (Mavs-/-)- or type I IFN receptor (Ifnar1-/-)-deficient mice were exposed to RSV ex vivo. Wild-type (wt) AMs but not Mavs-/- and Ifnar1-/- AMs produced inflammatory mediators in response to RSV. Furthermore, Mavs-/- and Ifnar1-/- AMs accumulated more RSV proteins than wt AMs, but the infection was abortive. Thus, RIG-I-like receptor-MAVS and IFNAR signalling are important for the induction of proinflammatory mediators from AMs upon RSV infection, but this signalling is not central for controlling viral replication. The ability to restrict viral replication makes AMs ideal sensors of RSV infection and important initiators of immune responses in the lung.

scholarly journals RFI-641, a Potent Respiratory Syncytial Virus Inhibitor

2002 ◽  
Vol 46 (3) ◽  
pp. 841-847 ◽  
Author(s):  
Clayton C. Huntley ◽  
William J. Weiss ◽  
Anna Gazumyan ◽  
Aron Buklan ◽  
Boris Feld ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Respiratory Tract Infections ◽  
Syncytium Formation ◽  
Therapeutic Window ◽  
Monkey Model ◽  
Cotton Rats ◽  
Syncytial Virus ◽  
Tract Infections

ABSTRACT Human respiratory syncytial virus (RSV), a paramyxovirus, is a major cause of acute upper and lower respiratory tract infections in infants, young children, and adults. RFI-641 is a novel anti-RSV agent with potent in vitro and in vivo activity. RFI-641 is active against both RSV type A and B strains. The viral specificity and the large therapeutic window of RFI-641 (>100-fold) indicate that the antiviral activity of the compound is not due to adverse effects on normal cells. The potent in vitro activity of RFI-641 can be translated to efficacy in vivo: RFI-641 is efficacious when administered prophylactically by the intranasal route in mice, cotton rats, and African green monkeys. RFI-641 is also efficacious when administered therapeutically (24 h postinfection) in the monkey model. Mechanism of action studies indicate that RFI-641 blocks viral F protein-mediated fusion and cell syncytium formation.

scholarly journals The larger attachment glycoprotein of respiratory syncytial virus produced in primary human bronchial epithelial cultures reduces infectivity for cell lines

2021 ◽  
Vol 17 (4) ◽  
pp. e1009469
Author(s):  
Tiffany King ◽  
Asuncion Mejias ◽  
Octavio Ramilo ◽  
Mark E. Peeples
Keyword(s):  
Respiratory Syncytial Virus ◽  
Cell Lines ◽  
Virus Infectivity ◽  
Bronchial Epithelial ◽  
Epithelial Cultures ◽  
Differential Infectivity ◽  
Syncytial Virus ◽  
Immortalized Cell ◽  
Tract Infections

Respiratory syncytial virus (RSV) infects the upper and lower respiratory tracts and can cause lower respiratory tract infections in children and elders. RSV has traditionally been isolated, grown, studied and quantified in immortalized cell lines, most frequently HEp-2 cells. However, in vivo RSV infection is modeled more accurately in primary well differentiated human bronchial epithelial (HBE) cultures where RSV targets the ciliated cells and where the putative RSV receptor differs from the receptor on HEp-2 cells. The RSV attachment (G) glycoprotein in virions produced by HEp-2 cells is a highly glycosylated 95 kDa protein with a 32 kDa peptide core. However, virions produced in HBE cultures, RSV (HBE), contain an even larger, 170 kDa, G protein (LgG). Here we show that LgG is found in virions from both subgroups A and B lab-adapted and clinical isolates. Unexpectedly, RSV (HBE) virions were approximately 100-fold more infectious for HBE cultures than for HEp-2 cells. Surprisingly, the cause of this differential infectivity, was reduced infectivity of RSV (HBE) on HEp-2 cells rather than enhanced infectivity on HBE cultures. The lower infectivity of RSV(HBE) for HEp-2 cells is caused by the reduced ability of LgG to interact with heparan sulfate proteoglycans (HSPG), the RSV receptor on HEp-2 cells. The discovery of different infectivity corresponding with the larger form of the RSV attachment protein when produced by HBE cultures highlights the importance of studying a virus produced by its native host cell and the potential impact on quantifying virus infectivity on cell lines where the virus entry mechanisms differ from their natural target cell.

scholarly journals Viral RNA N6-methyladenosine modification modulates both innate and adaptive immune responses of human respiratory syncytial virus

2021 ◽  
Vol 17 (12) ◽  
pp. e1010142
Author(s):  
Miaoge Xue ◽  
Yuexiu Zhang ◽  
Haitao Wang ◽  
Elizabeth L. Kairis ◽  
Mijia Lu ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Immune Responses ◽  
Adaptive Immunity ◽  
Human Respiratory Syncytial Virus ◽  
Viral Rna ◽  
Type I ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Syncytial Virus ◽  
Tract Infections

Human respiratory syncytial virus (RSV) is the leading cause of respiratory tract infections in humans. A well-known challenge in the development of a live attenuated RSV vaccine is that interferon (IFN)-mediated antiviral responses are strongly suppressed by RSV nonstructural proteins which, in turn, dampens the subsequent adaptive immune responses. Here, we discovered a novel strategy to enhance innate and adaptive immunity to RSV infection. Specifically, we found that recombinant RSVs deficient in viral RNA N6-methyladenosine (m6A) and RSV grown in m6A methyltransferase (METTL3)-knockdown cells induce higher expression of RIG-I, bind more efficiently to RIG-I, and enhance RIG-I ubiquitination and IRF3 phosphorylation compared to wild-type virion RNA, leading to enhanced type I IFN production. Importantly, these m6A-deficient RSV mutants also induce a stronger IFN response in vivo, are significantly attenuated, induce higher neutralizing antibody and T cell immune responses in mice and provide complete protection against RSV challenge in cotton rats. Collectively, our results demonstrate that inhibition of RSV RNA m6A methylation enhances innate immune responses which in turn promote adaptive immunity.

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