Development of an RSV Vaccine by Molecular Manipulation of the Viral Matrix Protein

 

Suport Period: 2013-2018

 

Project Leader: Tom Oomens, Ph.D., Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University

 

Mentors: 

Mark Coggeshall, Ph.D., Department of Arthritis & Clinical Immunology, Oklahoma Medical Research Foundation

Richard Eberle, Ph.D., Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University

Robert Welliver, M.D., Department of Pediatrics, College of Medicine, The University of Oklahoma Health Science Center

 

Project Summary:

 

Human Respiratory Syncytial Virus (HRSV) is the single largest viral cause of pediatric bronchiolitis and pneumonia. With an estimated mortality of >100,000 children per year worldwide, development of an anti-HRSV vaccine is a priority. Among the current approaches, live-attenuation is attractive because, unlike inactivated vaccines, it promises to induce a broad and balanced immune response. However, live HRSV vaccines have so far been unable to fully prevent potentially dangerous side-effects in infants and children.

 

The long-term objectives of this research are to overcome the safety challenges of live-attenuated HRSV vaccines and to contribute fundamental knowledge of the HRSV life cycle to design alternative anti-HRSV approaches. To meet these objectives, this proposal focusses on molecular manipulation of the viral matrix (M) protein to enhance safety of live-attenuated vaccines. The M protein is essential for replication and plays a prominent role in virion-assembly processes, many of which are highly relevant for the production, composition, release, and perhaps stability of virus particles. A better understanding of M functions therefore offers significant potential for vaccine advancements. A novel system was developed based on an infectious virus lacking the M gene (M-null) which allows rapid screening and manipulation of M functions.

 

By providing plasmids expressing M mutants to cells infected with the M-null virus, a preliminary screen identified M mutations with potential to regulate the level of infectious progeny production of a live virus. This proposal utilizes the M-null based system to likewise identify and manipulate assembly-relevant M functions and test the translational potential in vivo, through the following Specific Aims (abbreviated)

 

1. Identify M functions and mutations, and the underlying mechanisms, that regulate virus assembly, composition, and release.
2. Determine the quality of the immune response to live viruses with transmission-deficiencies based on M mutations, in vitro and in vivo.
3. Test promising M mutant viruses for ability to protect mice after challenge with wildtype HRSV.

 

Together these aims will raise our fundamental understanding of HRSV replication and test the potential of M protein manipulation to contribute to the generation of a safe live-attenuated vaccine.

 

Relevance:

 

Human Respiratory Syncytial Virus (HRSV) is responsible for the death of >100,000 children each year. An anti-HRSV vaccine is a priority but additional knowledge of virus replication and host immunity is needed to impart sufficient safety in a vaccine. This proposal maps and manipulates determinants of virus assembly and transmission and tests the potential to improve the safety of live-attenuated HRSV vaccines.

A Novel Tissue-Equivalent Respiratory Model to Study Airway Reactivity to Infectious Agents

 

Support Period: 2013-2018

 

Project Leader: Heather Gappa-Fahlenkamp, Ph.D., School of Chemical Engineering, College of Engineering and Architecture Technology, Oklahoma State University

 

Project Mentors: 

Gillian Air, Ph.D., Department Biochemistry and Molecular Biology, College of Medicine, The University of Oklahoma Health Science Center

Pamela Lovern, Ph.D., Department of Physiological Sciences, College of Veterinary Medicine, Oklahoma State University

Jordan Metcalf, M.D., Department of Medicine, Pulmonary and Critical Care, College of Medicine, The University of Oklahoma Health Sciences Center

 

Project Summary:

 

Influenza is a leading cause of human morbidity and mortality worldwide. In the United States, influenza is responsible for more than 30,000 deaths and 250,000 hospitalizations annually. The molecular mechanisms involved in the interaction of virus-infected resident lung cells and transmigrating antigen-presenting cell (APC) precursors that are recruited in response to viral infection have not been defined fully. Studies have shown that the highly pathogenic influenza strains lead to cytokine dysregulation and a massive infiltration of APC precursors into the lungs. The more pathogenic strains of the virus may alter cytokine/chemokine production of the alveolar epithelial cells and alveolar macrophages leading to increased migration and differentiation of activated APCs that drive an excessive inflammatory response.

 

Our goal is to develop a tissue-equivalent respiratory model (TERM) that exhibits a normal immunological response against infectious agents, and to use the model to study the molecular cross talk between influenza-infected resident lung cells and transmigrating APCs.  The TERM can be used to study the interplay of cell types within a complex environment, and it can be dissolved easily to isolate and study single cell populations.  We propose to develop the TERM and to define the contribution of each cell type to the excessive inflammatory response in a model recapitulating normal human lung with the following specific aims:

 

1. Create and characterize the TERM,
2. Use the TERM to determine differential abilities of a very pathogenic strain (H1N1) of influenza and a mildly pathogenic strain (H3N2) to drive key differences in the response of alveolar epithelial cells and macrophages that would result in a pathologic proinflammatory response or a protective antiviral immune response, and
3. Validate the TERM with a human lung organ culture model and an animal model of influenza.

 

A better understanding of these mechanisms can aid in the control of the delicate balance of an essential innate immune response to control early viral replication and an excessive inflammatory response that leads to cytokine-associated immunopathology.

 

Relevance:

 

This project uses a novel tissue-equivalent respiratory model (TERM) to identify the key mechanisms associated with the ability of pathogenic strains of the influenza virus to attract and differentiate lung cells to a highly inflammatory phenotype. These mechanisms will provide new targets for preventative and therapeutic interventions of influenza infection that will be tested in the TERM.  

Control of Lung Inflammation by a TLR4-interacting SP-A-derived Peptide

 

Support Period: 2013-2018

 

Project Leader: Shanjana Awasthi, Ph.D., Department of Pharmaceutical Sciences, College of Pharmacy, The University of Oklahoma Health Sciences Center

 

Project Mentors: 

Mark Coggeshall, Ph.D., Department of Arthritis & Clinical Immunology, Oklahoma Medical Research Foundation

Jordan Metcalf, M.D., Department of Medicine, Pulmonary and Critical Care, College of Medicine, The University of Oklahoma Health Sciences Center

Wendy Picking, Ph.D., Department of Microbiology and Molecular Genetics, College of Arts and Sciences, Oklahoma State University

 

Project Summary:

 

Lung infections are a major cause of morbidity and mortality worldwide. Serious lung infections lead to respiratory distress syndrome for which there is no specific treatment available. In the wake of rise in lung infections caused by multi-drug resistant pathogens and unavailability of a “wonder-drug” to control associated inflammation, it is important to develop novel therapies. An ideal therapeutic would be the one that can suppress the inflammatory response but preserve the anti-pathogen host defense and lung homeostasis.

 

Our long term goal is to develop therapies based on boosting the natural host defense mechanisms mediated by pathogen-recognition receptors. Surfactant protein (SP)-A and Toll-like receptor (TLR) are known as “secretory” and “signaling” pathogen-recognition receptors, respectively. Interaction between SP-A and TLR4 inhibits the TNF-α response but preserves the phagocytic activity of antigen-presenting cells. Thus, a TLR4-interacting region of SP-A, mimicking these properties of SP-A may be developed into a novel SP-A-based immunotherapeutic. Using cutting-edge technology, we have recently identified a TLR4-interacting region of SP-A (SPA4 peptide). The objective of this application is to define the biological relevance and determine the mechanism of action of SPA4 peptide. We hypothesize that the SPA4 peptide will inhibit TLR4-induced inflammation, while maintaining TLR4-mediated bacterial-phagocytosis and clearance.

 

The specific aims  are to:

 

1. determine if SPA4 peptide inhibits inflammatory responses and improves clinical symptoms in an animal model of lung inflammation,
2. determine if SPA4 peptide inhibits the inflammatory response and maintains the phagocytic response at a cellular level, and
3. assess the biological effects of SPA4 peptide in clinically-relevant animal models of lung infection and inflammation.

 

This project is innovative because it uses a unique concept of developing an immunotherapeutic that will not only control inflammation, but also help maintain anti-pathogen responses and lung homeostasis. It is expected that an SP-A-based therapeutic will have a significant impact on improving lung health during infection and inflammation.     

 

Relevance:

 

Lung infections and the resulting lung injury and inflammation are global public health concerns for which there is a compelling need to develop potent new therapeutics. This project evaluates therapeutic benefits and determines mechanism(s) of action of an immunomodulator derived from surfactant protein. The results of the study will help develop a novel immunotherapeutic to overcome infection and modulate inflammation. 

Neutrophil-Mediated Acute Lung Injury in Influenza Virus Pneumonia

 

Support Period: 2013-2018

 

Project Leader: Telugu A Narasaraju, Ph.D, Department of Physiological Sciences, College of Veterinary Medicine, Oklahoma State University

 

Project Mentors: 

Gillian Air, Ph.D., Department Biochemistry and Molecular Biology, College of Medicine, The University of Oklahoma Health Science Center

Lin Liu, Ph.D., Department of Physiological Sciences, College of Veterinary Medicine, Oklahoma State University

Robert Welliver, M.D., Department of Pediatrics, College of Medicine, The University of Oklahoma Health Science Center

 

Project Summary:

 

Unprecedented and frequent outbreaks by influenza viruses with rapid world-wide spread portend considerable global threats and are a major public health concern. Complications of acute respiratory distress syndrome (ARDS), a severe form of acute lung injury, remain major causes of death in influenza pneumonia. Due to high mutation rates introduced by the viral RNA polymerase and consequent resistance to antiviral drugs, controlling influenza-induced morbidity and mortality is a major challenge. Although type-specific immunization is effective, treatment of non-immunized infected patients with current antiviral agents is relatively ineffective. Because the pathology of the disease is largely mediated by the host response to infection, a therapeutic approach targeting both the virus and the host response is desirable.

 

The objective of this project is to understand the role of neutrophils in the pathogenesis of influenza virus and to develop a ‘combination drug therapy’ that targets both neutrophil-induced acute lung injury and the virus itself. Influenza infection in mice induces excessive neutrophil influx and high cytokine response in the lungs, which contributes to the immunopathology. Although neutrophil-mediated lung injury is clearly linked with influenza pathogenesis, the phenotypic characteristics and functional responsiveness of the neutrophils mediating the damage are not completely known.

 

Preliminary studies show that C-C chemokine receptor type 1 and type 3 (CCR1 and CCR3) are induced in neutrophils during influenza infection and that these neutrophils produce neutrophil extracellular traps, which exacerbate lung injury by causing endothelial damage. Overall hypothesis of this proposal is that induced CCR1 and CCR3 in neutrophils during influenza virus infection alter neutrophil’s functions and induction of neutrophil extracellular traps, thus contributing to lung injury.

 

The aims of this project are to

 

1. test this hypothesis by evaluating CCR1 and CCR3 regulation during influenza virus pneumonia
2. establish the functional roles of induced CCR1 and CCR3in neutrophils in acute lung injury
3. the results will be used to develop a combination drug therapy targeting neutrophil-mediated acute lung injury and the virus itself

 

Relevance:

 

The difficulty in vaccine preparation due to unprecedented emergence of new strains and high mutative ability of the virus, controlling influenza-induced morbidity and mortality is a major challenge. Because the pathology of the disease is largely mediated by the host response to infection, a therapeutic approach targeting both the virus and the host response is desirable, especially in influenza outbreaks. Thus, this proposal addresses a major problem in inflenza treament.