Ewald, Sarah E
Associate Professor, Microbiology, Immunology, and Cancer Biology
- BA, Biology, University of Massachusetts, Amherst
- PhD, Molecular and Cell Biology, University of California, Berkeley
- Postdoc, Immunoparasitology, Stanford University
Biochemistry, Biotechnology, Immunology, Infectious Diseases/Biodefense, Metabolism, Microbiology, Molecular Biology, Neuroimmunology, Neuroscience
Innate immunity, chronic disease, host-parasite interactions, Toxoplasma gondii, proteomics
How does the body recognize an infectious organism? During infection, how does it determine when to escalate inflammation for pathogen clearance versus dampen inflammation to prevent damage to self? What are the long term consequences of these 'immunological decisions' in the balance of health and chronic disease?
In the Ewald lab we want to understand how the innate immune system participates in these processes. To ask these questions we are interested in harnessing new technologies to examine human disease. We also study how the immune system interacts with the protozoan parasite Toxoplasma gondii: a pathogen with a long evolutionary relationship with both rodents and humans.
How does the innate immune system sense Toxoplasma?
Cell autonomous immune sensors survey the host cell for evidence of infection, often inducing host cell death in effort to kill intracellular pathogens. These pathways ave proving efficacious targets for vaccine development and tumor immune therapies; and dysregulation of these pathways due to genetic polymorphism is associated with a range of autoimmune conditions. Despite a better understanding these responses to bacterial and viral infection relatively little is known about the cell autonomous immune response to the protozoan parasite Toxoplasma gondii. Toxoplasma is perhaps the most successful mammalian parasite. This obligate intracellular organism has evolved strategies to intersect host signaling pathways, use host immune cells to traffic through the body and establishes chronic infection that lasts the life of the host. Parasite transmission absolutely depends on establishing chronic infection. In this way, survival of both host and parasite require an intact immune response. This implies a delicate balance of immune evasion and activation strategies driving parasite selection. We are interested in understanding how the parasite activates and manipulates the cell autonomous immune system particularly in the acute response when immune activation is needed. During chronic infection, however, parasite biology that compromises rodent fitness is beneficial because the parasite is transmitted to definitive feline hosts by predation. Our lab has observed that infected mice become chronically cachectic, a wasting disorder characterized by muscle loss that directly contributes to mortality in almost every chronic disease (including infection, fibrotic diseases, atherosclerosis and cance)r. We are using Toxoplasma infection as a novel model to understand immune and metabolic dysregulation driving chronic cachexia.
Automated Spatially targeted optical microproteomics or autoSTOMP is a novel technique that employs standard 2-photon immunofluorescence microscopy to define subcellular structures and selectively UV-cross link proteins in those structures to a modified biotin tag (UV-bio). Once samples are dissociated, labeled proteins are affinity purified and identified by LC-MS. Since the technique does not require genetic modification and overexpression of a label-targeting protein autoSTOMP can be performed on any primary cell or clinical sample where reagents are available to identify the structure of interest.
Our goal is to use autoSTOMP to understand inflammation and tissue pathology in the human body, where genetic tools and experimental manipulation are limited.
The Ewald Lab is currently accepting applications for post doctoral positions. For information contact email@example.com
The Ewald lab is accepting graduate trainees through The University of Virginia Biomedical Sciences Graduate Program (BIMS) and Medical Scientist Training Program