Recent Awardees

2016 Awardees

Scholar Awards

Ben A. Croker, Ph.D.
Harvard Medical School and Boston Children’s Hospital
Medicine-Hematology/Oncology
Non-apoptotic Death of Neutrophils and Eosinophils Drives Allergic Asthma
The cells that line the airways can send signals into the blood that recruit an inflammatory response. One of these signals is a protein called interleukin-33 (IL-33). When it is first released from airway cells, IL-33 is not especially potent, but its effect can be intensified by enzymes found in white blood cells. Dr. Croker proposes that this is an important mechanism at play in asthma–that the death of white blood cells in the lungs releases IL-33-activating enzymes, resulting in lung inflammation. If true, asthma could be blocked by preventing the death of white blood cells within the lung and/or blocking the enzymes that activate IL-33. He will test his hypothesis by examining asthma in mice lacking the triggers for white blood cell death and will explore the role of infection in activating this pathway in mice exhibiting asthma. Scientific Abstract
Camilla Forsberg, Ph.D.
University of California, Santa Cruz
Biomolecular Engineering
Defining the Developmental Origin of Asthma Susceptibility and Pathogenesis
Recent studies have shown an important connection between asthma and a small subset of white blood cells called “innate lymphocytes.” In prior studies, Dr. Forsberg discovered a type of stem cell that gives rise to innate lymphocytes. As part of her AAF-sponsored studies, she will further investigate the link between these stem cells and innate lymphocytes, and she will test the hypothesis that infections early in life (i.e., just preceding and following birth) disturb stem cell function and, consequently, the function of innate lymphocytes. If this proves to be the case, she will then examine the effect of disrupting stem cells in a mouse model of asthma. This may yield a better understanding of how early life events, especially infection, affect the risk of developing asthma. Scientific Abstract
Adam Frost, M.D., Ph.D.
University of California, San Francisco
Biochemistry and Biophysics
The Structural Basis of Heritable Human Asthma and Related Disorders of Sphingolipid Synthesis
Sphingosines are a structural component of cell membranes and are important regulators of cellular enzymes. Recent evidence has indicated that variation in sphingosine levels may play a role in asthma. Genetic studies of humans with asthma have shown that asthma varies with variations in the gene for a protein called ORMDL3, which regulates the synthesis of sphingosines. Thus, the protein ORMDL3 is a potential target for the treatment of asthma. To better understand how ORMDL3 works, and to facilitate the design of drugs that would affect ORMDL3 function, Dr. Frost proposes to determine the three-dimensional structure of ORMDL3 and of other proteins that associate with it within cellular membranes. His preliminary results suggest that the activity of ORMDL3 changes with the structural arrangement of proteins that bind to ORMDL3. He will examine the structure and function this functional complex to determine how deliberate changes in the arrangement of these proteins might alter the role of ORMDL3 in asthma. Scientific Abstract
Jody S. Rosenblatt, Ph.D.
University of Utah
Oncological Sciences
Inhibiting Bronchoconstriction-dependent Airway Epithelial Extrusion to Impede the Asthma Inflammatory Cycle
Cells that line the airways provide a protective barrier against chemicals and infections. These cells replicate quickly and must be cleared from the lungs at a similar rate; too many cells will clog the airways and too few will leave the lungs unprotected. Dr. Rosenblatt has found that these cells, collectively called the airway epithelium, maintain this critical balance through a mechanism that senses cell crowding. If the cells become too tightly packed, some cells are squeezed out by surrounding cells and are dislodged from the epithelium to die and to be cleared from the lungs. When airways constrict during an asthma attack, airway epithelia become hyper-crowded, causing extensive numbers of cells to extrude from the epithelium. When the airways relax and return to normal volume, gaps form in this barrier due to loss of too many epithelial cells. Dr. Rosenblatt hypothesizes that the resulting breaches in the epithelium may lead to the airway inflammation that follows an asthma attack, and that this inflammation may, in turn, lead to further attacks. Using a molecule known to block the extrusion of cells, Dr. Rosenblatt will test whether a reduction in cell extrusion leads to less inflammation and to a reduction in asthma. If so, this would be a new approach to treating asthma. Scientific Abstract
June L. Round, Ph.D.
University of Utah
Pathology
The Role of Air Pollution and Inhaled Microbes in Inducing Mucosal Immune Responses During Allergic Asthma
Air pollution makes asthma worse. Air pollutants trigger asthma, and they also provide a substrate for microbes, such as bacteria, to enter the lung. Normally, inhaled microbes are not sufficient to cause infection or to promote inflammation. Dr. Round proposes that inhaling microbes in association with air pollutants, however, can result in immune responses to the microbes, with consequent inflammation. Dr. Round will first test this hypothesis in humans by epidemiologic studies in which the air is sampled regularly for both pollutants and infectious agents, and the infectious agents will be compared to agents in the sputum from asthmatics who are seen in the emergency room for asthma attacks. Dr. Round further notes that asthmatics differ from non-asthmatics both in the types of bacteria in their lung and in their intestines. She proposes that that air pollutants and bacteria may enter the gut as well as the lung, altering the gut response to bacteria. She will test this theory in mice, and she will use a mouse model of asthma to test the effect on asthma of air pollutants and microbes both individually and in combination. The ability to quantify microbes in the air has only recently become possible by means of detecting their DNA or RNA. This has opened a new field of research, and Dr. Round’s approach will unite epidemiology with experimentation to bring this field to asthma. Scientific Abstract
Gregory F. Sonnenberg, Ph.D.
Weill Cornell Medicine
Medicine and Microbiology/Immunology
Regulating Disparate Proinflammatory CD4+ T Cells Asthma
Lymphocytes are white blood cells that mediate an immune response. There are many different types of lymphocytes, and Dr. Sonnenberg’s AAF studies focus on two of them: The first are CD4+ T cells, which generally activate an immune response, as they do in asthma. The second are innate lymphocytes (specifically, group 3 innate lymphocytes), which lack the antigen specificity of T cells (or B cells), but can respond to broad groups of pathogens. Dr. Sonnenberg’s laboratory has shown that some innate lymphocytes keep the CD4+ T cells in check; and mice with genetically impaired innate lymphocytes have increased inflammation in the lung. Because of the potential importance of this regulation in asthma, Dr. Sonnenberg will first examine how the innate lymphocytes suppress immunity to prevent excessive inflammation. Specifically he will test the possibility that they do so by taking up allergens (antigens) and then presenting them on the cell surface where they attract CD4+ T cells. When sufficiently close, the innate lymphocytes inactivate (perhaps kill) the CD4+ T cells, interrupting the immune response. Dr. Sonnenberg will focus next on specific bacterial allergens and will test the hypothesis that CD4+ T cells respond first to bacteria from the gut and secondarily to bacteria in the lungs. If this proves correct, he will attempt to understand why this occurs and whether this is a pathway by which the immune response in asthma could be controlled. Scientific Abstract
Matt R. Whorton, Ph.D.
Oregon Health and Science University
Cell and Structural Biology
Structure and Function of Adenylyl Cyclase
One of the mainstays of asthma therapy is the inhalation of bronchodilating drugs, which open the airways. These include short acting drugs, such as albuterol (Proventil) or metaproteranol, and long-acting drugs, such as salmeterol (Advair) or formoterol (Symbicort). These drugs interact with enzymes in airway muscle tissue to relax the muscles and open the airways. If we knew the molecular structures of these enzymes, which are called adenylyl cyclases, it might be possible to design better bronchodilating drugs. Dr. Whorton proposes to isolate and purify the adenylyl cyclases that are found in airway muscle, and then to determine the molecular structure of these enzymes in both their active and inactive state. These are challenging problems (which is why they have not previously been solved), but Dr. Whorton is accomplished in newer techniques that help to make the studies possible. Scientific Abstract

Extension Award

H. Eric Xu, Ph.D.
Van Andel Research Institute
Structural Biology
Development of Novel Glucocorticoids for Asthma Treatment
A mainstay of asthma therapy is the inhalation of corticosteroids, such as Flovent® or Qvar®, which reduce inflammation in the airways. Corticosteroids, however, have serious long-term side effects. Although the side effects are less severe when the drug is inhaled than when the drug is administered systemically, they remain an issue in the long-term treatment of asthma. Dr. Xu has probed the molecular structure of corticosteroids in order to design drugs that retain or increase their anti-inflammatory activity but have reduced side effects. Through this approach he has developed a drug that is more potent than current corticosteroids when tested in mice, allowing it to be used at lower doses with less side effects. With his AAF Extension Award, Dr. Xu will perform further animal studies with this and another drug candidate in order to advance these new therapies to clinical trials in patients. Scientific Abstract

2016 Awards Project Abstracts

Ben A. Croker, Ph.D. — 2016 Scholar Award

Harvard Medical School and Boston Children’s Hospital

Non-apoptotic Death of Neutrophils and Eosinophils Drives Allergic Asthma

IL-33 drives asthma in animal models and its expression is correlated with disease severity in humans with asthma and chronic obstructive pulmonary disease (COPD). Genome wide association studies have linked Il33 and Il1rl1 (the receptor for IL-33) to asthma susceptibility. IL-33 is released from airway epithelial cells where it activates hematopoietic cells to promote allergic inflammation via the production of IL-13 and IL-5. A wealth of information exists on the biological effects of IL-33, including T cell differentiation, mast cell survival and activation, eosinophil degranulation, dendritic cell maturation, macrophage production of CCL24 and CCL17, and the regulation of IL-33 by the soluble IL-33 receptor. However, major gaps exist in our understanding of the cell types and the biochemical mechanisms that regulate IL-33 processing and activity. This study focuses on approaches to limit the processing and hyper-activation of IL-33. IL-33 lacks a signal peptide but can be released from viable airway epithelial progenitor cells where it can be further processed to a highly bioactive cytokine by proteases including neutrophil elastase and cathepsin G. Activation of the receptor interacting protein kinase-3 (RIPK3)/mixed lineage kinase domain-like (MLKL)-dependent necroptotic pathway can contribute to the generation of bioactive IL-33 isoforms that are consistent with processing by neutrophil proteases. Our preliminary data reveals that necroptosis of neutrophils triggers the formation of neutrophil extracellular traps (NETs) composed of DNA, histones and proteases including neutrophil elastase. The observation of NETs in human endobronchial biopsy specimens from asthma patients suggests that neutrophils may contribute to IL-33-mediated IL-4/5/13 production via a propensity to engage the necroptosis pathway. In this model, proteases associated with NETs from necroptotic neutrophils will proteolytically cleave IL-33 and increase its activity on surrounding cell types. In this study, we will examine a role for neutrophil necroptosis in IL-33 hyperactivation in response to house dust mite allergen and pulmonary S.pneumoniae infection, which is known to increase the risk of wheeze and asthma.

Camilla Forsberg, Ph.D. — 2016 Scholar Award

University of California, Santa Cruz

Defining the Developmental Origin of Asthma Susceptibility and Pathogenesis

Despite the well-documented impact of early life exposure on asthma risk, the mechanisms by which early life events increase asthma susceptibility are poorly understood. The discovery of a new class of immune cells, innate lymphocytes, as critical mediators of asthma pathology has advanced approaches to asthma treatment; however, limited understanding of the development of these cell subsets presents a barrier for defining the cellular origins of asthma susceptibility. In this proposal, we aim to capitalize on our recent discovery of a developmentally restricted hematopoietic stem cell (HSC) that gives rise to innate lymphocytes to establish a novel model for investigating the developmental origins of asthma susceptibility. We will define the role of this novel HSC in the generation of innate lymphocytes that mediate asthma pathogenesis, and identify the molecular regulators of their unique capability (Aim 1). We then aim to define how perinatal immune insult, modeled by acute treatment with the TLR agonist poly(IC), perturbs developmental hematopoiesis and innate lymphocyte establishment (Aim 2). Specifically, we will investigate whether perinatal insult triggers the abnormal persistence of the developmentally limited HSC and the effects of this persistence on the cellularity of developmentally regulated immune cells in adulthood. Lastly, we will determine whether perinatal immune insult influences asthma susceptibility and define the cellular drivers of increased asthma risk (Aim 3). Together, these experiments will yield critical information regarding the origin of the cells that drive asthma pathogenesis, and determine how adverse life events translate into increased risk of asthma later in life.

Adam Frost, M.D., Ph.D. — 2016 Scholar Award

University of California, San Francisco

The Structural Basis of Heritable Human Asthma and Related Disorders of Sphingolipid Synthesis

Sphingolipids and their derivatives have emerged in recent years as major autocrine and paracrine signals within epithelial tissues that strongly influence cell survival and inflammation. Human genome-wide association studies have established a robust asthma risk allele on chromosome 17q21 that impacts the expression of the gene ORMDL3, a protein that directly impacts sphingolipid homeostasis. Specific manipulations of sphingolipid levels in model organisms, moreover, induces an asthma-like phenotype. Together, these observations suggest that the enzymes governing sphingolipid synthesis may be novel therapeutic targets for asthma and other diseases because the ORMDL3 allele has also been linked to several heritable inflammatory disorders. ORMDL3 is an integral component of a poorly understood membrane protein complex, the SPOTS complex, which includes enzymes responsible for the first and rate-determining step of sphingolipid synthesis as well as a glycerolipid phosphatase. We have purified functionally active SPOTS complexes for structural and functional studies and propose to (1) determine the structural mechanisms by which ORMDL3 regulates sphingolipid homeostasis; and (2) to determine the molecular basis of cross-talk between glycerolipid and sphingolipid homeostasis with the SPOTS complex. We are poised to determine the atomic-resolution mechanisms governing the SPOTS complex and thereby to overcome the roadblock limiting further basic investigations and pharmaceutical developments for sphingolipid diseases.

Jody S. Rosenblatt, Ph.D. — 2016 Scholar Award

University of Utah

Inhibiting Bronchoconstriction-dependent Airway Epithelial Extrusion to Impede the Asthma Inflammatory Cycle

Airway epithelia provide a protective barrier for our lungs, warding off air-borne toxins and pathogens. The cells comprising these epithelia renew at some of the fastest rates in the body by cell death and division. Yet, the number of cells that die must match those that divide to prevent barrier function diseases or tumors from arising. My lab has discovered that when cells become too crowded, some extrude and die, thereby mechanically matching the number of cells dying to those dividing. The stretch-activated channel, Piezo1, senses crowding and triggers cells to emit Sphingosine 1-Phosphate, which activates Rho-mediated actomyosin contraction to seamlessly squeeze cells out of the epithelium. While 1.6-fold crowding triggers cells to extrude and die during normal turnover, we found that excessive crowding from an asthmatic bronchoconstriction causes excessive extrusion that destroys the airway epithelial barrier. Disruption of the epithelial lining could lead to the typical weeklong inflammatory period and high infection susceptibility that follows an attack. Further, this inflammation could promote more asthma attacks. Because crowding-induced epithelial cell extrusion requires Piezo1, we discovered that the stretch-activated channel inhibitor gadolinium (an MRI contrast agent) prevents epithelial extrusion and denuding from bronchoconstriction. Here, we will test if gadolinium treatment can prevent the inflammatory period following an attack and avert future attacks using a pre-clinical mouse model, by addressing the following aims: 1. Does hyper-extrusion following bronchoconstriction cause inflammation? 2. Test if gadolinium prevents bronchoconstrictive airway denuding in a pre-clinical mouse model. 3. Does pre-treating with gadolinium prevent asthma attacks?

June L. Round, Ph.D. — 2016 Scholar Award

University of Utah

The Role of Air Pollution and Inhaled Microbes in Inducing Mucosal Immune Responses During Allergic Asthma

Numerous commensal microbes normally exist in the lung with no adverse effect on host health. During allergic asthma, excessive immune responses to environmental antigens, including inhalable microbes, results in disease. This disease can be exacerbated by environmental insults such as air pollution that may cause irritation and facilitate excessive immune responses. Heavy air pollution events with high levels of particulate matter have been shown to increase the abundance of inhalable microbes. The combination of increased environmental insults with increased microbial burdens due to air pollution has not been explored as a potential cause of allergic airway disease such as asthma. In this proposal we will test the hypothesis that alterations to the inhalable microbes and noxious particles during air pollution events results in increased allergic asthma type responses to otherwise innocuous environmental microbes. This increased immune response in the lung is mediated by the effects of air pollution causing an increased exposure in the intestines to inhaled microbial antigens due to increased intestinal permeability in the presence of air pollutants. We will test this hypothesis using human samples and animal models by addressing the following specific aims: Aim 1. Does air pollution alter the environmental airborne and host-associated airway microbiota and responses to microbes in allergic asthma? Aim 2. Do constituents of air pollution increase intestinal pathogenesis and immune responses to microbes in the lung?

Gregory F. Sonnenberg, Ph.D. — 2016 Scholar Award

Weill Cornell Medicine

Regulating Disparate Proinflammatory CD4+ T Cells Asthma

Asthma is a chronic disease resulting from a dysregulated immune response to environmental, microbial or allergic stimuli in the lung. Basic and translational studies suggest that asthma is orchestrated by the priming, expansion and effector functions of antigen-specific CD4+ T cells. Despite tremendous advances in understanding the pathogenesis of asthma, there is currently limited knowledge on pathways that can directly limit pathologic CD4+ T cell responses to defined antigens. In recent studies we have identified a novel regulatory pathway at another mucosal surface of the mammalian body, the intestinal tract. Specifically, we identified that an innate immune cell population, termed group 3 innate lymphoid cells (ILC3), directly limits pathologic CD4+ T cell responses to microbes through expression of major histocompatibility complex class II (MHCII). Furthermore, we now identify that MHCII+ ILC3 are enriched in the lung-draining lymph node and limit Th2 and Th17 cell responses in the lungs of allergen-exposed mice. Strikingly, the mixed Th2 and Th17 cell responses have different antigen-specificities towards allergens and microbes. In this proposal we will systematically interrogate: (i) whether ILC3-intrinsic MHCII regulates allergen-specific CD4+ Th2 cells in the asthmatic lung, and (ii) how ILC3-intrinsic MHCII is regulating microbe-specific CD4+ Th17 cells in the asthmatic lung. Collectively, these studies will employ our expertise in mucosal immunology and host-microbe interactions to investigate the role and functional significance of this novel regulatory pathway in the lung. Further, these studies may inform ongoing efforts to develop effective therapies targeting either ILCs or CD4 T cells to treat asthma.

Matt R. Whorton, Ph.D. — 2016 Scholar Award

Oregon Health and Science University

Structure and Function of Adenylyl Cyclase

Adenylyl cyclases are enzymes that convert ATP into the second messenger cyclic AMP. Their activity is regulated by a variety of factors, and they play important roles in many physiological processes, including the control of airway smooth muscle tone. They mediate the therapeutic effects of the beta agonist class of bronchodilators, and direct activation by small molecule activators has been shown to cause bronchodilation. However, the lack of high-resolution structural information for a full-length adenylyl cyclase has limited our understanding of the molecular mechanisms that regulate their activity, and has also hindered their development as a therapeutic target. In this proposal, I aim to utilize biochemical and biophysical approaches to elucidate detailed mechanisms for regulatory control of this class of proteins. This will entail developing methods for the expression and purification of a full-length adenylyl cyclase and then structure determination of the adenylyl cyclase both by itself as well as in complex with its various regulators. The results will have a significant impact on our understanding of adenylyl cyclase structure and function, as well as the role these enzymes play in the pathophysiology of asthma, and may also lead to the development of compounds that directly target these proteins.

H. Eric Xu, Ph.D. — 2016 Extension Award

Van Andel Research Institute

Development of Novel Glucocorticoids for Asthma Treatment

Glucocorticoids are the most effective treatment for asthma. However, their clinical applications are limited by low efficacy and unwanted side effects. Therefore, it is important to develop novel glucocorticoids that deliver high efficacy to the lungs with fewer side effects. Supported by previous AAF funding, we have gained structural insights into glucocorticoid potency and the molecular mechanism of dissociated glucocorticoids. We found that high potency can be achieved by designing ligands with a lipophilic group at the C-17α position of the steroid D ring. Further, the dissociation of transactivation from transrepression can be achieved by designing small molecules that interfere with the dimerization of the glucocorticoid receptor ligand-binding domain. Applying that knowledge, we have developed an exceptionally potent glucocorticoid, VSGC12, which efficiently represses the inflammation signals in a murine asthma model and outperforms the leading asthma drugs currently used in clinics. VSGC12 can deliver effective treatment at a low dose without eliciting major side effects such as insulin resistance and bone loss. We have also developed a partially dissociated glucocorticoid, VSG111, which has promise for lowering unwanted side effects. Our specific aims are 1) preclinical evaluation of VSGC12 through intranasal administration in a mouse asthma model; 2) drug metabolism and pharmacokinetics (DMPK) and toxicity studies of VSGC12; and 3) preclinical evaluation the efficacy of VSG111 in a mouse asthma model. Achieving these specific aims will provide the basis for developing new drug candidates for treating asthma, which would fulfil the mission of AAF extension award toward an impact on therapy.