Reproduction and Growth in a Murine Model of Early Life-Onset Inflammatory Bowel Disease.

RESEARCH INTERESTS
Last Updated: 27 October 2020

My laboratory uses genetically-modified mice to study the roles that certain genes and gene products play in the presentation of abnormal neuroendocrine, neurological, and psychiatric responses. Traditionally, the identification of neuroendocrine dysfunction has involved biochemical analyses of hormonal responses, those for neurological disorders have relied upon behavioral and postmortem analyses, and those for psychiatric conditions have depended upon phenomenology.  The use of genetic technologies has allowed specific genes in selected cells and in neural pathways to be related to certain molecular, biochemical, cellular, physiological, and behavioral dysfunctions. As the Director of the Mouse Behavioral and Neuroendocrine Analysis Core Facility at Duke University (http://sites.duke.edu/mousebehavioralcore/), we have phenotyped many different lines of inbred and mutant mice for my own work as well as for investigators at Duke and at other research institutions. As a consequence, we have helped to develop many different mouse genetic models of neuroendocrine and neuropsychiatric illness. We are working also with academic medicinal chemists and/or certain pharmacological/biotechnological companies to identify novel compounds that will ameliorate abnormal responses in various mutant mouse models. Some of these preclinical studies have formed a basis for clinical trials in humans.

My laboratory is broadly interested in how large changes in nutritional status (e.g. malnutrition or obesity) influence T cell immunity.  Malnutrition can lead to immunodeficiency and increased risk of infection, whereas obesity is associated with inflammation that promotes multiple diseases including autoimmunity, type 2 diabetes, and cardiovascular disease.  We have identified the adipocyte-secreted hormone leptin as a critical link between nutrition and immunity.  Leptin is secreted from adipocytes in proportion to adipocyte mass and is therefore decreased in malnutrition and increased in obesity.  We have found that leptin is a critical regulator of effector T cell glucose metabolism and thereby drives effector T cell activation.  From these initial findings, we have established further lines of investigation, as summarized here.

(1) Determining molecular mechanisms of T cell dysfunction in malnutrition – Our goal is to identify metabolic and epigenetic mechanisms by which malnutrition and decreased leptin alter T cell function leading to increased susceptibility to infection and protection against autoimmune diseases.  We study this using a mouse model of autoimmunity, experimental autoimmune encephalomyelitis (EAE).

(2) Elucidating mechanisms of T cell inflammation in obesity-induced type 2 diabetes – Our goal is to identify molecular and metabolic mechanisms by which obesity alters the Teff/Treg balance, resulting in inflammation and subsequent insulin resistance leading to type 2 diabetes.  With our collaborators from UNC Chapel Hill, we are also identifying immunometabolic changes in obese animals and humans that correlate with increased susceptibility to influenza.

(3) Determining the role of insulin and IGF-1 in regulating T cell function and metabolism – Our goal is to identify how insulin influences both T cell glucose uptake and T cell differentiation/cytokine production and determine the role of insulin signaling in T cells in the setting of obesity-associated diabetes.  We hypothesize that insulin has a direct role in T cell function through its abiltiy to alter T cell glucose metabolism, influence T cell cytokine production, and impact the pathophysiology of obesity-associated type 2 diabetes. 

The Hale laboratory employs techniques of cellular and molecular biology to study mechanisms responsible for the generation of both normal immune responses and immune-mediated diseases. Research in the laboratory is mainly focused on inflammatory bowel disease (IBD), an immune-mediated disorder that is hypothesized to result from the abnormal immune response of a genetically susceptible host to the antigens derived from enteric bacteria. Development of optimal treatments for disease requires a detailed understanding of mechanisms of disease pathogenesis. Thus current work in the laboratory is aimed at understanding triggers of intestinal inflammation and mechanisms of inflammation-associated neoplasia, in addition to developing novel therapies for IBD treatment. Ongoing research also includes investigating mechanisms that determine the immunogenicity of oral antigens, to develop novel adjuvants for oral vaccines. This work has relevance for pathogenesis and treatment of infectious diseases affecting the gastrointestinal tract, as well as for inflammatory bowel disease.

Dr. Hale is an expert in pathologic evaluation of colitis and immunodeficiency in both humans and mice and is board-certified in Anatomic and Clinical Pathology.