Awardees and Abstracts

2015 Awardees

Scholar Awards

Hongbo Chi, Ph.D.
St. Jude Children's Research Hospital
Immunology
Metabolic Programming and Targeting of T Cell Responses in Asthma
There are different types of immune responses. The immune response in both asthma and allergy has features of a so-called “Th2” response. A Th2 response is marked by elevated IgE antibodies and elevated eosinophils. Much has been learned about how the Th2 response is directed by certain “interleukins,” proteins that travel between cells to guide the immune response. Recent studies have shown, however, that this is only part of the story. The Th2 immune response requires an alteration in the metabolism of immune cells. In particular T lymphocytes highly upregulate glucose metabolism as their main source of energy. Dr. Chi has been involved in studies showing that this change in metabolism is dependent on a protein complex expressed inside T lymphocytes called “mTORC1” (mammalian target of rapamycin complex). In preliminary studies for his AAF work, he showed that mice in which T lymphocytes lack functional mTORC1 are deficient in a Th2 immune response and are strongly protected from asthma. Further, he showed that loss of mTORC1 reduces the expression of genes that are required to shift metabolism to glucose. In his proposed work, he will dissect the molecular pathways by which mTORC1 regulates glucose metabolism. At the same time, he will screen for potential drugs that can block Th2 differentiation. This two-pronged approach will speed the potential translational application of the studies into clinical use.  Scientific Abstract
Min Guo, Ph.D.
Scripps Research Institute - Florida
Cancer Biology
Targeting LysRS-MITF Pathway for Inhibiting Late-phase Allergic Response and Asthma
Mast cells are white blood cells that reside in tissue rather than circulate in the blood. They are filled with proteins that, when released into the surrounding tissue, promote the type of allergy and inflammation seen in asthma. This release can be triggered when mast cells encounter antigen-bound IgE antibody, and asthma is generally improved when IgE is depleted, because the activation of mast cells is reduced. Dr. Guo and his colleagues previously demonstrated that mast cell activation is dependent on an enzyme in the cells called LysRS (lysyl-tRNA synthetase). They will first examine the levels of activated LysRS in asthma by studying asthmatic mice. Next they will screen for drugs that block the activity of LysRS. Finally, they will test candidate drugs for their ability to block asthma in mice. As an essential enzyme for protein synthesis, LysRS has not previously been studied as a potential target for the treatment of asthma. Scientific Abstract
Chyi S. Hsieh, M.D., Ph.D.
Washington University
Medicine-Rheumatology
Role of Commensal Bacterial in Asthma
The most common type of antibody in the gut is IgA, which is secreted into the intestinal lumen. Recent studies have shown that intestinal IgA in patients with inflammatory bowel disease binds specifically to bacteria that cause intestinal inflammation when they are introduced into the gut of mice. In preliminary studies, Dr. Hsieh and his colleagues have found that patients with asthma also have IgA antibodies against specific subsets of intestinal bacteria. They now propose to expand these studies both in size and in scope, to verify the association of asthma with the immunologic findings in the gut, and to isolate and characterize the bacteria identified by the IgA antibodies. Additionally, they will examine the intestinal contents of mice with asthma, looking at their effect on one arm of the immune system, T lymphocytes. Specifically, they will test the hypothesis that the intestinal bacteria identified by IgA selectively activate those T lymphocytes that can respond to antigens in the lungs, triggering asthma.  Scientific Abstract
Quan Lu, Ph.D.
Harvard School of Public Health
Molecular and Integrative Physiological Sciences
Cholecystokinin (CCK) and Its Receptor CCKAR as Novel Therapeutic Targets for Asthma
In asthma, airways narrow because the muscles around the airways tighten. Dr. Lu, who is a geneticist and molecular biologist, had found that airway smooth muscles (or ASM) express high levels of the genes for the hormone cholecystokinin (CCK) and its receptor CCKAR. Previous knowledge of CCK came largely from studies of the gut and the brain, where CCK is produced in response to eating and regulates satiety. CCK is alsoknown to contract ASM, but this feature has been little studied. Dr. Lu confirmed this effect and showed that CCK acts on ASM by binding to the receptor CCKAR on the surface of ASM. He proposes that this effect may be important in asthma. Further, CCK is elevated in obese mice, and Dr. Lu proposes that this may help to explain why obesity is linked to asthma. Dr. Lu proposes first to examine the regulation of CCK expression, and he will look at the interaction of CCK with drugs used to treat asthma. He will then study mice with asthma in order to determine if asthma can be improved by blocking the binding of CCK to its receptor. Finally, he will test the hypothesis that blockade of CCK will reduce asthma in obese mice. The studies have the potential both to identify a new pathway for therapy in asthma and to reveal a role for this pathway in linking asthma to obesity. Scientific Abstract
SangKon Oh, Ph.D.
Baylor Research Institute
Immunology
Anti-DC-ASGPR Antibody-based Therapeutic Approach for Allergic Asthma
The immune system has its own police system, a subset of white blood cells that constrains immunity rather than enhance it. These cells are called regulatory T cells (Tregs). Tregs can broadly reduce the immune response, but they can also selectively suppress the immune response against specific antigens. Thus, one approach to autoimmunity would be to selectively expand Tregs that are specific for the autoimmune response. The expansion and activation of Tregs requires another type of white blood cell, the dendritic cell (DC). In his studies of macaques, Dr.Oh found that the activation of Tregs by DCs can be enhanced by exposing the DCs to antibody that recognizes a specific protein on their surface, the DC-asialoglycoprotein receptor. By linking this antibody to an antigen he can induce Tregs that selectively suppress immunity against that antigen, whether it be a self-antigen or a foreign protein. To examine the potential role of this response in asthma, he will begin with in vitro studies of the activation of human Tregs by DCs. In particular, he will seek to suppress the immune response against antigens from house mites, which are a common stimulus to asthma. He will also examine the effect of DCs on B cells, the immune cells that produce antibodies. He will perform similar studies using human lung DCs to generate Tregs. Finally, he will assess the efficacy of treating asthma with antibody to the DC asialoglycoprotein receptor, using a mouse model of asthma in which the mice express the human DC asialoglycoprotein receptor. The use of the body’s own regulatory system to control asthma has special appeal, as it may provide a long-lasting response. Scientific Abstract
Eric P. Skaar, Ph.D.
Vanderbilt University
Pathology, Microbiology & Immunology
The Role of Dietary Metals and Calprotectin in the Pathogenesis of Asthma
Zinc has been proposed as a therapy for problems as diverse as the common cold and loss of memory. It is required for the activity of a broad range of enzymes, and it functions as an antioxidant. But while zinc deficiency is known to lead to reduced immunity, as well as growth retardation and mental deficiency, there has never been a clearly established role for zinc supplementation beyond normal levels in the treatment or prevention of illness. Dr. Skaar proposes, however, that zinc supplementation may be important in the treatment of asthma. Inflammatory white blood cells (neutrophils) contain high levels of a protein called calprotectin, which binds to zinc, forming a compound that helps to fight infection. Tissue levels of the calprotectin-zinc complex are high in lung inflammation, and Dr. Skaar notes that calprotectin-zinc may thus help to protect the lungs from oxidative damage, and he has preliminary evidence to support this hypothesis. Furthermore, preliminary studies by other investigators have shown that intravenous calprotectin protects against asthma in a rat model. For his AAF studies, Dr. Skaar will first examine the effect of dietary zinc on a mouse model for allergic asthma, including extensive studies of airway fluid, obtained by bronchoscopy. He will then compare the effects of zinc on asthma in mice deficient or sufficient in calprotectin. Finally, he will use sophisticated technology to define the amount and the distribution of oxidized calprotectin in mice with asthma that have been given graded amounts of dietary zinc. If supplemental zinc is beneficial in asthma, it will be a low-cost treatment with few side effects. Scientific Abstract

Extension Awards

Bruce D. Hammock, Ph.D.
University of California, Davis
Entomology and Cancer Research Center
Soluble Epoxide Hydrolase is a Novel Therapeutic Target in Asthma
White blood cells (leukocytes) manufacture a group of chemicals called leukotrienes, which induce inflammation and cause airway muscle to constrict. Singulair®, a drug used to treat asthma, works by blocking the activity of several of the leukotrienes. In the white blood cells, leukotrienes are made from arachidonic acid. Arachidonic acid, however, is also converted into other biologically active molecules, including a group of molecules called epoxyeicosatrienoic acids (EETs). EETs generally suppress inflammation and airway constriction, but they are rapidly degraded by a single enzyme to biologically less active, and even inflammatory, products. Through his AAF-sponsored studies, Dr. Hammock and his group have developed drugs that block this conversion of EETs, have shown that these drugs reduce asthma when given systemically, and have demonstrated that the drugs work even better when given together with drugs that block the formation of leukotrienes or when paired with an omega-3 rich diet. His AAF extension award will allow him to perform pre-clinical studies in order to advance his therapy to clinical trials. Specifically, he will test high doses of the drug for toxicity in vitro and in rodents and he will use a mouse model of asthma to test whether the drug is effective when administered by inhalation rather than by systemic injection.  Scientific Abstract
Joshua Rokach, Ph.D.
Florida Institute of Technology
Chemistry
5-Oxo-ETE: A Novel Inflammatory Mediator
Asthma and allergies are usually marked by high levels of white blood cells called eosinophils. Eosinophils are attracted to sites of allergic inflammation by a chemical called 5-Ox0-ETE. Dr. Rokach has designed and synthesized a drug that blocks the effects of 5-Oxo-ETE. In order to take this into clinical trials, he proposes preclinical studies to improve the efficacy of the drug, to determine its pharmacology, and to test its efficacy in animal models of airway eosinophilia as well as skin eosinophilia.  Scientific Abstract

2015 Awards Project Abstracts

Hongbo Chi, Ph.D. — 2015 Scholar Award

St. Jude Children's Research Hospital

Metabolic Programming and Targeting of T Cell Responses in Asthma

TH2 cells play a key role in asthmatic pathogenesis. While current studies of TH2 differentiation are mainly focused on cytokine signaling and transcription factors, emerging evidence highlights that coordination of T cell metabolic programs with fate decisions is a fundamental issue in adaptive immunity. However, how the metabolic programs intersect with immune signals in T cell fates and functions is poorly defined. Our recent studies have revealed an indispensable role for mTORC1 signaling in TH2 cell differentiation and asthmatic pathogenesis. Mechanistically, mTORC1 coordinates multiple metabolic programs including glycolysis and lipid/cholesterol synthesis. These findings therefore implicate mTORC1 as a prototypical pathway to link immune signaling and cell metabolism. Our overarching hypothesis is that the interplay between mTORC1 and metabolic programs orchestrates a novel checkpoint for TH2 cell differentiation and asthmatic pathogenesis. Specifically, we will: (1) Establish the interplay between mTORC1 signaling and metabolic reprogramming in TH2 cell differentiation. (2) Determine the metabolic signature and requirement for TH2 cell differentiation. Insights from this study may impact our understanding of metabolic reprogramming and TH2 cell biology and manifest new therapeutic opportunities for asthma.

Min Guo, Ph.D. — 2015 Scholar Award

Scripps Research Institute - Florida

Targeting LysRS-MITF Pathway for Inhibiting Late-phase Allergic Response and Asthma

With major unmet therapeutic needs to ameliorate disease, discovery of a novel medication for asthma, preferably a mast cell specific stabilizer, remains a central goal of research in this area. Our previous studies established that the lysyl- tRNA synthetase (LysRS) is a critical upstream regulator of mast cell activation–in fact, through an on/off switch. Specifically, our studies have defined a mechanism by which phosphorylation changes the structure and function of LysRS, which ultimately leads to the activation of gene transcription of MITF (microphthalmia-associated transcription factor)-target inflammatory mediators, that are responsible for both the early and late-phase allergic responses. The goals of this proposal are to determine the role of this important LysRS-MITF pathway of mast cell activation in asthma, and to develop small molecular probes that function as LysRS-specific inhibitors for potential asthma therapy, particularly in late-phase asthmatic responses such as airway remodeling. In pursuit of these important goals we will (1) Determine the role of the LysRS-MITF pathway in airway mast cells. (2). Develop novel LysRS allosteric inhibitors for blocking LysRS-MITF activation in mast cells. (3) Characterize the LysRS inhibitors in reducing the burden of asthma. The proposed work seeks to break new ground by applying knowledge outside the field of immunity and using instead our expertise in tRNA synthetases to the study of asthma and of novel therapeutics. With the support of research labs and HTS the high throughput screening center at Scripps Florida, we are the best situated to carry out this exciting new research project and rapidly translate it into clinic.

Bruce D. Hammock, Ph.D. — 2015 Extension Award

University of California, Davis

Soluble Epoxide Hydrolase is a Novel Therapeutic Target in Asthma

Asthma is a chronic inflammatory disease mediated by cysteinyl leukotrienes (cys-LTs) and characterized by a T helper type 2 (Th2) cell-dependent inflammatory responses leading to airflow obstruction and airway hyperresponsiveness (AHR). Our previous studies demonstrated that inhibition of soluble epoxide hydrolase (sEH), the enzyme that converts anti-inflammatory epoxyeicosatrienoic acids (EETs) to the corresponding dihydroxyeicosatrienoic acids (DHETs), and the resulting increase in EETs, leads to down-regulation of a number of cytokines and enzymes induced during inflammation, such as cyclooxygenase 2 (COX-2) and lipoxygenase 5 (5-LOX). In this AAF extension award, we propose to test the feasibility of using sEHI in an aerosol to treat airway inflammation in the murine asthmatic model. We are currently funded by an SBIR from NIEHS to continue IND enabling studies specific for pain relief. Extension funding from AAF will allow us to leverage those on-going safety studies and generate additional data needed to submit a second IND application for the treatment for asthma. The specific aims are: Aim 1: Test the safety of sEHI via inhalation at high doses in a rat pulmonary toxicity study. This study will provide preliminary data for developing IND-enabling toxicity protocols for asthma. Aim 2: Test the efficacy of three sEHIs in attenuating pulmonary inflammation when administrated by inhalation in an OVA-induced mouse asthma model. Investigate (i) target engagement by monitoring plasma and tissue levels of inhibitors and EpFAs and (ii) mechanism of action by measuring inflammatory cytokine profiles, pulmonary immune cell recruitment, lung function

Chyi S. Hsieh, M.D., Ph.D. — 2015 Scholar Award

Washington University

Role of Commensal Bacterial in Asthma

Recent studies have suggested that the intestinal microbiota may play a role in asthma pathogenesis. To address this, we performed a pilot study of fecal bacteria in pediatric asthma patients. Using 16S rDNA next-generation sequencing to profile the microbiota, we observed decreased diversity of fecal bacteria in asthma patients. We also performed flow cytometry to assess the binding of endogenously secreted immunoglobulin A (IgA) to fecal bacteria. Interestingly, we found that the commensal intestinal bacteria bound to IgA are different in asthma patients, suggesting that immune responses to intestinal bacteria may play a role in asthma. Here, we propose to solidify these preliminary human studies by expanding the cohort of patients and assessing longitudinally whether these changes are associated with disease activity (Aim 1). We will also begin to assess how the intestinal immune response to commensal bacteria is associated with asthma. First, we will ask whether airway and intestinal bacteria are related in these patients (Aim 1). Second, we will characterize the intestinal bacteria associated with asthma and address whether they have unique genomic features and whether they can modulate murine asthma models (Aim 2). Finally, we will test the hypothesis that T cell trafficking between the lung and intestine explains the association between gut bacteria and asthma, by using high throughput analysis of the T cell receptor repertoire (Aim 3). Thus, these proposed studies will establish whether immune responses to intestinal commensal bacteria are associated with human asthma and will address potential mechanisms by which intestinal bacteria affect immune responses in the lung.

Quan Lu, Ph.D. — 2015 Scholar Award

Harvard School of Public Health

Cholecystokinin (CCK) and Its Receptor CCKAR as Novel Therapeutic Targets for Asthma

A key feature of asthma is airflow limitation, often characterized by hyperactive contraction of airway smooth muscle (ASM) cells. Consequently, a major therapeutic goal for asthma is to reduce ASM constriction. We have recently discovered that the peptide hormone cholecystokinin (CCK) and its receptor CCKAR, which are best known for regulating food intake and functions of the gastrointestinal tract, are expressed in and induce the contraction of primary human ASM cells. Our preliminary studies further showed that CCK expression in ASM cells is induced by both β-agonists and fatty acids. Moreover, CCK expression is elevated in the lungs of obese mice. We hypothesize that autocrine activation of CCKAR by elevated CCK in the ASM reduces airway relaxation by β-agonists and contributes to obesity-associated airway hyperresponsiveness (AHR). To test this hypothesis, we will further characterize the function and regulation of CCK/CCKAR signaling in human ASM cells (aim 1), investigate the role of CCK/CCKAR in inhibiting β-agonist-mediated bronchoprotection in mice (aim 2), and determine whether antagonizing CCK/CCKAR attenuates the innate AHR associated with obesity (aim 3). Results from this study will provide critical pre-clinical evidence required for developing CCK/CCKAR antagonists—most of them initially identified for treating gastrointestinal diseases--into new therapeutics for asthma. Furthermore, given that obesity is increasingly recognized as an important risk factor for asthma and that obese asthmatics respond poorly to existing therapies, our research may lead to much-needed therapeutic options for obese asthmatics.

SangKon Oh, Ph.D. — 2015 Scholar Award

Baylor Research Institute

Anti-DC-ASGPR Antibody-based Therapeutic Approach for Allergic Asthma

Asthma is a highly heterogeneous inflammatory disease of the airway comprised of distinct clinical, immunologic, and genetic phenotypes. Nonetheless, an allergen-induced inflammatory response is one of the leading causes of asthma. Regulatory T cells (Tregs) are fundamental for the maintenance of immune homeostasis. The balance between Tregs and pathogenic T cells can play a decisive role in the development and progression of allergic asthma. Thus, a strategy that can efficiently mount allergen-specific Tregs in patients has great value for the treatment of allergic asthma. Dendritic cells (DCs) are major immune inducers and controllers. DCs in the airways play a central role in the pathogenesis of allergic asthma. However, DCs can also control allergic asthma by the induction of Tregs. A key remaining question is how to manipulate in vivo DCs to mount Tregs in asthma patients. We have recently discovered that activation of DCs via DC-asialoglycoprotein receptor (DC-ASGPR) with αDC-ASGPR antibody (mAb) can efficiently mount IL-10-producing antigen-specific Tregs. In this study, we therefore propose to test three aims: Aim 1: To investigate the effects of αDC-ASGPR mAb on asthma patient CD4+ T and B cell responses in vitro. Aim 2: To investigate the effects of αDC-ASGPR mAb on human lung DC functions to induce and activate CD4+ T cell responses in vitro. Aim 3: To investigate the effectiveness of αDC-ASGPR mAb on an animal model of allergic asthma. Data from this study will be fundamental for testingαDC-ASGPR mAb in a phase I trial in the near future.

Joshua Rokach, Ph.D. — 2015 Extension Award

Florida Institute of Technology

5-Oxo-ETE: A Novel Inflammatory Mediator

Forthcoming.

Eric P. Skaar, Ph.D. — 2015 Scholar Award

Vanderbilt University

The Role of Dietary Metals and Calprotectin in the Pathogenesis of Asthma

A growing body of evidence has linked alterations in dietary zinc levels to the incidence of asthma and the protective effects of zinc are modeled to be due to its antioxidant properties. We have previously discovered that calprotectin is one of the most abundant proteins during lung inflammation, and calprotectin exhibits potent zinc binding activities, suggesting that this protein is a key contributor to zinc distribution during inflammation. Notably, oxidized calprotectin has been identified at high levels in the lungs of asthmatic patients, and calprotectin has been modeled to have a protective role as an oxygen scavenger. Based on these observations, we hypothesize that calprotectin has a dual function as an antioxidant in the lung whereby its zinc binding properties contribute to airway zinc distribution while its oxygen scavenging properties protect against oxidative damage. Further, we hypothesize that the protective role of calprotectin during asthma is affected by dietary zinc levels. This model will be tested through a series of three integrated specific aims. In Aim 1 we will elucidate the impact of altered dietary zinc on asthma pathogenesis. Aim 2 studies will determine the contribution of calprotectin to metal distribution during asthma. Finally, experiments in Aim 3 will define the abundance and distribution of oxidized calprotectin in the asthmatic lung. Taken together, the results of these experiments will reveal the importance of dietary zinc and calprotectin in the pathogenesis of asthma and will lay the groundwork for the development of therapeutics and interventions for the treatment of asthma.