Professor, Transplant Surgery
Associate Dean, ADM-Medicine Administration
Director, Medical Student Research
Director, Department of Surgery Research Training Program
PI, NIH T32 Advanced Research Training in Immunology for Surgical Research Trainees
Director, College of Medicine's Master of Medical Science Program
Columbus, Ohio 43210
Research interests: My laboratory-based investigations are focused on the discovery of novel mechanisms that regulate de novo alloantibody production after transplant to uncover new targets for development of immunotherapeutics. These studies address the clinical problem of antibody-mediated allograft damage by investigating mechanisms that 1) drive or downregulate alloAb production or 2) cause tissue damage mediated by alloAb effector pathways.
In addition, we test the relative efficacy of conventional and novel immunotherapeutics to suppress alloAb production to see if it interferes with alloAb-mediated graft damage and prolongs allograft survival. Well-developed experimental models are used to study allograft rejection mediated by alloAb alone (e.g., in Rag1 KO recipients), in vivo and in vitro cytotoxicity of alloprimed B cells, in vivo CD8-mediated suppression of alloprimed B cell antibody production, in vitro co-cultures to investigate CD8-mediated suppression of CD4+ T follicular helper cells and methods to enrich for CD8+ T Ab suppressor cells. Using these and other models, my research team was the first to discover a role for iNKT cells in critically enhancing the magnitude of alloAb production post-transplant and also the first to discover a novel CD8-dependent pathway which downregulates alloAb production post-transplant. Studies to date indicate that alloAb-mediated parenchymal cell injury is complement-independent, NK-independent and relies on macrophage dependent cytotoxic effector mechanism. My lab collaborates with experts in transplant immunology, tumor immunology and B cell biology.
Research lab mission statement: The Bumgardner Transplant Immunology Laboratory research goals are to investigate adaptive and innate immune responses to both cellular and solid organ transplants to spearhead development of novel immunotherapies, which will prolong transplant allograft survival.
Current research: The focus of our current research is to:
- More precisely identify the unique characteristics of a novel antibody suppressing CD8+ T cell subset and to investigate the cellular and molecular mechanisms critical for their activation, maturation and expansion.
- Study mechanisms by which CD8+ T Ab suppressor cells suppress development and function of IL-4- and IL-21- producing CD4+ T follicular helper cells. These studies have significant potential clinical impact to suppress alloantibody production post-transplant as well as to suppress ongoing antibody mediated rejection.
- Pursue human transplant immunology research to determine if donor specific alloantibody development is regulated by a subset of CD8+ T regulatory cells.
A transgenic functional hepatocyte transplant model is used to study immunogenicity of allogeneic parenchymal cells.
Some research techniques that are commonly used in the laboratory include small animal surgery, liver cell isolation, injection of monoclonal antibodies, splenocyte isolation, phlebotomy, adoptive transfer of cell populations, in vitro cell culture, flow cytometry, immunohistochemistry, cell viability assays, ELISA, ELISPOT and confocal microscopy.
Active funding: NIH/NIAID
- Undergraduate Education: College of William and Mary
- Medical degree: University of Virginia School of Medicine
- PhD: Surgery, Transplant Immunology, University of Minnesota
- Residency: General Surgery, University of Minnesota
- Fellowship: Transplant Surgery, University of California San Francisco Medical Center
- Fellowship: Surgical Endoscopy, University of Minnesota
- Fellowship: Surgical Infectious Disease, University of Minnesota
- Surgeon scientist article, Bumgardner quoted in general surgery news, 2016
- Selected to participate in OSU Project REACH program designed to inspire female entrepreneurship, 2016
- Selected to serve on the American College of Surgeon’s Board of Governors, 2016
- Deputy editor, Liver Transplantation, 2015
- OSU Courage to Teach Award, 2014
- Elected councilor-at-large of the American Society of Transplant Surgeons, 2014 - 2017
- Voted by peers for the “Best Doctors List” for central Ohio, 2005 - 2015
- Excellence in Teaching Award, The Ohio State University College of Medicine Department of Surgery, 2005