Mucosal immunity and vaccines against viral infections

Mucosal immunity is realized through a structural and functional system called mucose-associated lymphoid tissue (MALT). MALT is subdivided into parts (clusters) depending on their anatomical location, but they all have a similar structure: mucus layer, epithelial tissue, lamina propria and lymphoid follicles. Plasma cells of MALT produce a unique type of immunoglobulins, IgA, which have the ability to polymerize. In mucosal immunization, the predominant form of IgA is a secretory dimer, sIgA, which is concentrated in large quantities in the mucosa. Mucosal IgA acts as a first line of defense and neutralizes viruses efficiently at the portal of entry, preventing infection of epithelial cells and generalization of infection. To date, several mucosal antiviral vaccines have been licensed, which include attenuated strains of the corresponding viruses: poliomyelitis, influenza, and rotavirus. Despite the tremendous success of these vaccines, in particular, in the eradication of poliomyelitis, significant disadvantages of using attenuated viral strains in their composition are the risk of reactogenicity and the possibility of reversion to a virulent strain during vaccination. Nevertheless, it is mucosal vaccination, which mimics a natural infection, is able to induce a fast and effective immune response and thus help prevent and possibly stop outbreaks of many viral infections. Currently, a number of intranasal vaccines based on a new vector approach are successfully undergoing clinical trials. In these vaccines, the safe viral vectors are used to deliver protectively significant immunogens of pathogenic viruses. The most tested vector for intranasal vaccines is adenovirus, and the most significant immunogen is SARSCoV-2 S protein. Mucosal vector vaccines against human respiratory syncytial virus and human immunodeficiency virus type 1 based on Sendai virus, which is able to replicate asymptomatically in cells of bronchial epithelium, are also being investigated.

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A Respiratory Syncytial Virus Vaccine Vectored by a Stable Chimeric and Replication-Deficient Sendai Virus Protects Mice without Inducing Enhanced Disease

Journal of Virology ◽

10.1128/jvi.02298-16 ◽

2017 ◽

Vol 91 (10) ◽

Cited By ~ 6

Author(s):

Marian Alexander Wiegand ◽

Gianni Gori-Savellini ◽

Claudia Gandolfo ◽

Guido Papa ◽

Christine Kaufmann ◽

...

Keyword(s):

Respiratory Syncytial Virus ◽

Elderly People ◽

Neutralizing Antibodies ◽

Viral Vectors ◽

Sendai Virus ◽

Genome Replication ◽

F Protein ◽

A Genome ◽

Syncytial Virus ◽

Vectored Vaccine

ABSTRACT Respiratory syncytial virus (RSV) is a major cause of severe respiratory infections in children and elderly people, and no marketed vaccine exists. In this study, we generated and analyzed a subunit vaccine against RSV based on a novel genome replication-deficient Sendai virus (SeV) vector. We inserted the RSV F protein, known to be a genetically stable antigen, into our vector in a specific way to optimize the vaccine features. By exchanging the ectodomain of the SeV F protein for its counterpart from RSV, we created a chimeric vectored vaccine that contains the RSV F protein as an essential structural component. In this way, the antigen is actively expressed on the surfaces of vaccine particles in its prefusion conformation, and as recently reported for other vectored vaccines, the occurrence of silencing mutations of the transgene in the vaccine genome can be prevented. In addition, its active gene expression contributes to further stimulation of the immune response. In order to understand the best route of immunization, we compared vaccine efficacies after intranasal (i.n.) or intramuscular (i.m.) immunization of BALB/c mice. Via both routes, substantial RSV-specific immune responses were induced, consisting of serum IgG and neutralizing antibodies, as well as cytotoxic T cells. Moreover, i.n. immunization was also able to stimulate specific mucosal IgA in the upper and lower respiratory tract. In virus challenge experiments, animals were protected against RSV infection after both i.n. and i.m. immunization without inducing vaccine-enhanced disease. Above all, the replication-deficient SeV appeared to be safe and well tolerated. IMPORTANCE Respiratory syncytial virus (RSV) is a major cause of respiratory diseases in young children and elderly people worldwide. There is a great demand for a licensed vaccine. Promising existing vaccine approaches based on live-attenuated vaccines or viral vectors have suffered from unforeseen drawbacks related to immunogenicity and attenuation. We provide a novel RSV vaccine concept based on a genome replication-deficient Sendai vector that has many favorable vaccine characteristics. The specific vaccine design guarantees genetic stability of the transgene; furthermore, it supports a favorable presentation of the antigen, activating the adaptive response, features that other vectored vaccine approaches have often had difficulties with. Wide immunological and pathological analyses in mice confirmed the validity and efficacy of this approach after both parenteral and mucosal administration. Above all, this concept is suitable for initiating clinical studies, and it could also be applied to other infectious diseases.

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How Innate Immune Mechanisms Contribute to Antibody-Enhanced Viral Infections

Clinical and Vaccine Immunology ◽

10.1128/cvi.00316-10 ◽

2010 ◽

Vol 17 (12) ◽

pp. 1829-1835 ◽

Cited By ~ 90

Author(s):

Sukathida Ubol ◽

Scott B. Halstead

Keyword(s):

Dengue Virus ◽

Measles Virus ◽

Viral Infections ◽

Natural Infection ◽

Innate Immune ◽

Th2 Cells ◽

Wild Type Virus ◽

Severe Dengue ◽

Syncytial Virus

ABSTRACT Preexisting antibodies may enhance viral infections. In dengue, nonneutralizing antibodies raised by natural infection with one of four dengue viruses (DENVs) may enhance infection with a different virus by a process we term “intrinsic antibody-dependent enhancement” (iADE). In addition, nonprotective antibodies raised by formalin-inactivated respiratory syncytial virus (RSV) and measles virus vaccines have led to enhanced disease during breakthrough infections. Infections under iADE conditions not only facilitate the process of viral entry into monocytes and macrophages but also modify innate and adaptive intracellular antiviral mechanisms, suppressing type 1 interferon (IFN) production and resulting in enhanced DENV replication. The suppression observed in vitro has been documented in patients with severe (dengue hemorrhagic fever [DHF]) but not in patient with mild (dengue fever [DF]) secondary dengue virus infections. Important veterinary viral infections also may exhibit iADE. It is thought that use of formalin deconforms viral epitopes of RSV, resulting in poor Toll-like receptor (TLR) stimulation; suboptimal maturation of dendritic cells with reduced production of activation factors CD40, CD80, and CD86; decreased germinal center formation in lymph nodes; and the production of nonprotective antibodies. These antibodies fail to neutralize RSV, allowing replication with secondary stimulation of RSV-primed Th2 cells producing more low-avidity antibody, resulting in immune complexes deposited into affected tissue. However, when formalin-inactivated RSV was administered with a TLR agonist to mice, they were protected against wild-type virus challenge. Safe and effective vaccines against RSV/measles virus and dengue virus may benefit from a better understanding of how innate immune responses can promote production of protective antibodies.

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Detection of Nucleic Acids in Cells or Tissue Sections Using In situ Polymerase Chain Reaction (PCR)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100162545 ◽

1996 ◽

Vol 54 ◽

pp. 16-17

Author(s):

J. R. Hully ◽

K. R. Luehrsen ◽

K. Aoyagi ◽

C. Shoemaker ◽

R. Abramson

Keyword(s):

Nucleic Acids ◽

Viral Infections ◽

Anatomical Location ◽

Rt Pcr ◽

Reverse Transcription Pcr ◽

Cellular Source ◽

Gene Transcripts ◽

Initial Description ◽

In Cells

The development of PCR technology has greatly accelerated medical research at the genetic and molecular levels. Until recently, the inherent sensitivity of this technique has been limited to isolated preparations of nucleic acids which lack or at best have limited morphological information. With the obvious exception of cell lines, traditional PCR or reverse transcription-PCR (RT-PCR) cannot identify the cellular source of the amplified product. In contrast, in situ hybridization (ISH) by definition, defines the anatomical location of a gene and/or it’s product. However, this technique lacks the sensitivity of PCR and cannot routinely detect less than 10 to 20 copies per cell. Consequently, the localization of rare transcripts, latent viral infections, foreign or altered genes cannot be identified by this technique. In situ PCR or in situ RT-PCR is a combination of the two techniques, exploiting the sensitivity of PCR and the anatomical definition provided by ISH. Since it’s initial description considerable advances have been made in the application of in situ PCR, improvements in protocols, and the development of hardware dedicated to in situ PCR using conventional microscope slides. Our understanding of the importance of viral latency or viral burden in regards to HIV, HPV, and KSHV infections has benefited from this technique, enabling detection of single viral copies in cells or tissue otherwise thought to be normal. Clearly, this technique will be useful tool in pathobiology especially carcinogenesis, gene therapy and manipulations, the study of rare gene transcripts, and forensics.

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HIV Universal Vaccine

Molecular and Cellular Therapies ◽

10.26781/2052-8426-2018-05 ◽

2018 ◽

Vol 6 (1) ◽

Author(s):

Marek Malecki ◽

Bianka Saetre

Keyword(s):

Viral Infections ◽

Natural Infection ◽

High Specificity ◽

Molecular Medicine ◽

High Efficacy ◽

Therapeutic Vaccines ◽

Rapid Reduction ◽

Universal Vaccine ◽

Healthy Donors ◽

Induced Immunity

Background: For many deadly viruses, there are no preventive and / or therapeutic vaccines approved by health authorities World-wide (e.g., HIV, Ebola, Dengue, and many others). Although, for some viruses, prophylactic vaccines are very effective (e.g., HBV, Polio, Rota, and many others). In this realm, we design, manufacture, test, and streamline into the clinics novel viral universal vaccines (VUV). VUV have such unique features, that medical vaccination or natural infection induced immunity against some viruses (e.g., HBV) in patients, who became infected with other viruses (e.g., HIV), upon the VUV’s administration, is redirected against these other, newly infecting viruses (e.g., HIV). Specific Aim: The specific aim of this work was biomolecular engineering of the HIV universal vaccine (HIVUV) comprising the two main functional domains: CD4 or anti-gp120 - as the HIV tagging domain and HBsAg - as the immune response eliciting domain, so that upon its administration the HBV medical immunization or natural infection induced immunity would be redirected, accelerated, and amplified to fight the HIV infection. Healthy Donors and Patients: Per the Institutional Review Board approval and in compliance with the Declaration of Helsinki, all healthy donors and patients were presented with the Patients’ Bill of Rights and provided Patient Informed Consent. All the procedures were pursued by the licensed medical doctors. Methods & Results: We have biomolecularly engineered HIV universal vaccine (HIVUV) comprising human CD4 or anti-gp120 and HBsAg of HBV. By immunoblotting and magnetic activated molecular sorting, we have demonstrated high specificity of this vaccine in binding HIV. By flow cytometry and nuclear magnetic resonance, we have demonstrated high efficacy of these vaccines to engage HBV immunized patients’ immune system to work against HIV. Administration of HIVUV to blood or lymph of the HIV+ patients resulted in rapid reduction of the HIV viremia down to undetectable. It also resulted in protection of populations of CD4+ cells against HIV caused decline. Conclusions: We have demonstrated the proof of concept for high efficacy of VUV, specifically HIVUV, in annihilating HIV. Nevertheless, the same compositions, processes, and methods, for persons skilled in biotechnology, pharmacogenomics, and molecular medicine, are adaptable for other deadly viral infections, which we vigorously pursue.

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Evolution of the Seroprevalence of Pestivirus and Respiratory Viral Infections in Spanish Feedlot Lambs

Animals ◽

10.3390/ani11010160 ◽

2021 ◽

Vol 11 (1) ◽

pp. 160

Author(s):

Teresa Navarro ◽

Aurora Ortín ◽

Oscar Cabezón ◽

Marcelo De Las Heras ◽

Delia Lacasta ◽

...

Keyword(s):

Viral Infections ◽

Clinical Signs ◽

Production Performance ◽

Herpesvirus Type ◽

Bovine Herpesvirus Type 1 ◽

Feedlot Lambs ◽

Syncytial Virus ◽

Type 3 ◽

Bovine Parainfluenza Virus

The presence of respiratory viruses and pestiviruses in sheep has been widely demonstrated, and their ability to cause injury and predispose to respiratory processes have been proven experimentally. A longitudinal observational study was performed to determine the seroprevalence of bovine parainfluenza virus type 3 (BPIV-3), bovine respiratory syncytial virus (BRSV), bovine herpesvirus type 1 (BHV-1) and pestiviruses in 120 lambs at the beginning and the end of the fattening period. During this time, the animals were clinically monitored, their growth was recorded, and post-mortem examinations were performed in order to identify the presence of pneumonic lesions in the animals. Seroconversion to all viruses tested except BHV-1 was detected at the end of the period. Initially, BPIV-3 antibodies were the most frequently found, while the most common seroconversion through the analysed period occurred to BRSV. Only 10.8% of the lambs showed no detectable levels of antibodies against any of the tested viruses at the end of the survey. In addition, no statistical differences were found in the presentation of respiratory clinical signs, pneumonic lesions nor in the production performance between lambs that seroconverted and those which did not, except in the case of pestiviruses. The seroconversion to pestiviruses was associated with a reduction in the final weight of the lambs.

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Differential Mucin Expression by Respiratory Syncytial Virus and Human Metapneumovirus Infection in Human Epithelial Cells

Mediators of Inflammation ◽

10.1155/2015/347292 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 10

Author(s):

Ma. Del Rocío Baños-Lara ◽

Boyang Piao ◽

Antonieta Guerrero-Plata

Keyword(s):

Immune Response ◽

Respiratory Syncytial Virus ◽

Epithelial Cells ◽

Viral Infections ◽

Human Metapneumovirus ◽

Human Epithelial Cells ◽

Mucin Expression ◽

Rsv Infection ◽

Syncytial Virus ◽

Tract Disease

Mucins (MUC) constitute an important component of the inflammatory and innate immune response. However, the expression of these molecules by respiratory viral infections is still largely unknown. Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two close-related paramyxoviruses that can cause severe low respiratory tract disease in infants and young children worldwide. Currently, there is not vaccine available for neither virus. In this work, we explored the differential expression of MUC by RSV and hMPV in human epithelial cells. Our data indicate that the MUC expression by RSV and hMPV differs significantly, as we observed a stronger induction of MUC8, MUC15, MUC20, MUC21, and MUC22 by RSV infection while the expression of MUC1, MUC2, and MUC5B was dominated by the infection with hMPV. These results may contribute to the different immune response induced by these two respiratory viruses.

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Clinical use of Antiviral Drugs

Drug Intelligence & Clinical Pharmacy ◽

10.1177/106002808702100501 ◽

1987 ◽

Vol 21 (5) ◽

pp. 399-405 ◽

Cited By ~ 5

Author(s):

Milap C. Nahata

Keyword(s):

Influenza A ◽

Viral Infections ◽

Antiviral Agent ◽

Antiviral Drugs ◽

Investigational Drug ◽

Virus Infections ◽

Herpes Encephalitis ◽

Herpes Simplex Viruses ◽

Varicella Zoster ◽

Syncytial Virus

Remarkable progress has been made in antiviral chemotherapy. Six approved antiviral drugs are now available for the treatment of various viral infections. Trifluridine, idoxuridine and vidarabine are all effective in patients with herpes keratitis; trifluridine is preferred due to its low toxicity. Acyclovir is the drug of choice in patients with infections due to herpes simplex viruses, including genital herpes, herpes encephalitis, and neonatal herpes, and infections due to varicella-zoster virus. Amantadine is the only drug currently available for prophylaxis and treatment of influenza A, but an investigational drug, rimantadine, appears to be equally effective and less toxic than amantadine. Ribavirin is the most recently approved antiviral agent for the treatment of respiratory syncytial virus infections. Numerous antiviral drugs are being studied in patients with acquired immunodeficiency syndrome. Although currently available drugs have improved our ability to manage a variety of viral illnesses, much needs to be learned about specific dosage guidelines based on the studies of pharmacokinetics, pharmacodynamics, potential adverse effects and viral resistance, and the role of combination therapy to optimize therapy.

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Neonatal Viral Infections: Enteroviruses and Respiratory Syncytial Virus

Neonatology ◽

10.1007/978-3-319-18159-2_256-1 ◽

2016 ◽

pp. 1-8

Author(s):

Paolo Manzoni ◽

Davide Montin ◽

Elena Tavella ◽

Pier-Angelo Tovo

Keyword(s):

Respiratory Syncytial Virus ◽

Viral Infections ◽

Syncytial Virus

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Neonatal Viral Infections: Enteroviruses and Respiratory Syncytial Virus

Neonatology ◽

10.1007/978-3-319-29489-6_256 ◽

2018 ◽

pp. 1785-1792

Author(s):

Paolo Manzoni ◽

Davide Montin ◽

Elena Tavella ◽

Pier Angelo Tovo

Keyword(s):

Respiratory Syncytial Virus ◽

Viral Infections ◽

Syncytial Virus

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Potential Neurocognitive Symptoms Due to Respiratory Syncytial Virus Infection

Pathogens ◽

10.3390/pathogens11010047 ◽

2021 ◽

Vol 11 (1) ◽

pp. 47

Author(s):

Catalina A. Andrade ◽

Alexis M. Kalergis ◽

Karen Bohmwald

Keyword(s):

Respiratory Syncytial Virus ◽

Viral Infections ◽

Respiratory Infections ◽

The Elderly ◽

Cell Types ◽

Potential Effect ◽

Viral Agent ◽

Pulmonary Manifestations ◽

Syncytial Virus ◽

Tract Infections

Respiratory infections are among the major public health burdens, especially during winter. Along these lines, the human respiratory syncytial virus (hRSV) is the principal viral agent causing acute lower respiratory tract infections leading to hospitalization. The pulmonary manifestations due to hRSV infection are bronchiolitis and pneumonia, where the population most affected are infants and the elderly. However, recent evidence suggests that hRSV infection can impact the mother and fetus during pregnancy. Studies have indicated that hRSV can infect different cell types from the placenta and even cross the placenta barrier and infect the fetus. In addition, it is known that infections during the gestational period can lead to severe consequences for the development of the fetus due not only to a direct viral infection but also because of maternal immune activation (MIA). Furthermore, it has been described that the development of the central nervous system (CNS) of the fetus can be affected by the inflammatory environment of the uterus caused by viral infections. Increasing evidence supports the notion that hRSV could invade the CNS and infect nervous cells, such as microglia, neurons, and astrocytes, promoting neuroinflammation. Moreover, it has been described that the hRSV infection can provoke neurological manifestations, including cognitive impairment and behavioral alterations. Here, we will review the potential effect of hRSV in brain development and the potential long-term neurological sequelae.

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