Gregory David Sempowski, PhD

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Professor in Medicine
Professor of Pathology
Department / Division:
Medicine / Medicine - DHVI Faculty
Address:
909 S. Lasalle St
Rm 1005 Global Health Research Building,
Durham, NC 27705
Office Telephone:
(919) 684-4386
Training:
  • PhD, University of Rochester, 1996
Research Interests:
The laboratory of Gregory Sempowski, PhD studies immune senescence associated with aging.  Immune senescence is the gradual deterioration of the immune system due to natural age.  The Sempowski lab is primarily focused on developing strategies to enhance T cell reconstitution to offset thymic immune depletion due to immunodeficiency associated with aging, stress, or illness. The thymus plays an important role in maintaining the peripheral T cell pool in children and adults. As the thymus gets smaller with age, it produces significantly lower amounts of T cells resulting in an overall reduced immune response in older individuals. Currently, there are no treatments available to protect against aging, stress or illness-related thymic atrophy or accelerate recovery, thus leaving the immune system compromised. 

The Sempowski group is working to define the mechanisms that drive thymic involution and find ways of blocking or reversing thymic involution in order to enhance host response in at-risk populations against potential natural or man-made biothreats. The lab has identified the IL-6 cytokine gene family (i.e., leukemia inhibitory factor, IL-6, and oncostatin M) as thymosuppressive agents by the observation that they can acutely involute the thymus when injected into a young, healthy mouse. They also have identified leptin as a novel, thymostimulatory agent that can protect against stress-induced acute thymic atrophy. Identified hormones, cytokines and inhibitors of cytokine receptors are being tested as possible strategies to stimulate thymopoiesis and T cell reconstitution in mouse models of vaccination and infectious challenge.

DHVI Shared Resources 
Dr. Gregory Sempowski is Scientific Director for all DHVi Shared Resources and specifically oversees the DHVI Flow Facility and the collaborative research resources in the NIAID-Regional Biocontainment Laboratory at Duke (RBL).   The RBL offers services in the areas of Bacteriology, Virology and Immunology to DHVI and Duke Investigators and their collaborators, and to researchers within the Research Triangle community. Specific services include:  training in BSL3/ABSL3 and SA work, use of the containment environments, maintenance of pathogen inventories and propagation and QC of pathogen stocks for in vitro and in vivo studies.  In addition the three Core Units provide a menu of support assay such as CFU, viral load, neutralization and animal challenge models.  We are currently providing qualified animal models for pulmonary tuberculosis, bubonic plague, pneumonic plague, West Nile Virus infection, cryptococcosis, tularemia, and Yellow Fever.  These animal models are currently used to support NIAID-funded research for investigators at Duke University, the University of North Carolina at Chapel Hill, North Carolina State University, Harvard University, and the Centers for Disease Control (CDC).
Representative Publications:
  • Brickey, WJ; Neuringer, IP; Walton, W; Hua, X; Wang, EY; Jha, S; Sempowski, GD; Yang, X; Kirby, SL; Tilley, SL; Ting, JP. MyD88 provides a protective role in long-term radiation-induced lung injury. International Journal of Radiation Biology. 2012;88:335-347.  Abstract
  • Chinn, IK; Blackburn, CC; Manley, NR; Sempowski, GD. Changes in primary lymphoid organs with aging. Seminars in Immunology. 2012;24:309-320.  Abstract
  • Gonzalez, RJ; Weening, EH; Frothingham, R; Sempowski, GD; Miller, VL. Bioluminescence imaging to track bacterial dissemination of Yersinia pestis using different routes of infection in mice. BMC Microbiology. 2012;12:147.  Abstract
  • Kanda, J; Chiou, LW; Szabolcs, P; Sempowski, GD; Rizzieri, DA; Long, GD; Sullivan, KM; Gasparetto, C; Chute, JP; Morris, A; McPherson, J; Hale, J; Livingston, JA; Broadwater, G; Niedzwiecki, D; Chao, NJ; Horwitz, ME. Immune recovery in adult patients after myeloablative dual umbilical cord blood, matched sibling, and matched unrelated donor hematopoietic cell transplantation. Biology of Blood and Marrow Transplantation. 2012;18:1664-1676.e1.  Abstract
  • Mendoza, AE; Neely, CJ; Charles, AG; Kartchner, LB; Brickey, WJ; Khoury, AL; Sempowski, GD; Ting, JP; Cairns, BA; Maile, R. Radiation combined with thermal injury induces immature myeloid cells. Shock. 2012;38:532-542.  Abstract
  • Thompson, AL; Johnson, BT; Sempowski, GD; Gunn, MD; Hou, B; DeFranco, AL; Staats, HF. Maximal adjuvant activity of nasally delivered IL-1¿ requires adjuvant-responsive CD11c(+) cells and does not correlate with adjuvant-induced in vivo cytokine production. Journal of Immunology. 2012;188:2834-2846.  Abstract
  • Zhu, W; Ventevogel, MS; Knilans, KJ; Anderson, JE; Oldach, LM; McKinnon, KP; Hobbs, MM; Sempowski, GD; Duncan, JA. Neisseria gonorrhoeae suppresses dendritic cell-induced, antigen-dependent CD4 T cell proliferation. PLoS One. 2012;7:e41260.  Abstract
  • Billard, MJ; Gruver, AL; Sempowski, GD. Acute endotoxin-induced thymic atrophy is characterized by intrathymic inflammatory and wound healing responses. PLoS One. 2011;6:e17940.  Abstract
  • Cain, DW; Snowden, PB; Sempowski, GD; Kelsoe, G. Inflammation triggers emergency granulopoiesis through a density-dependent feedback mechanism. PLoS One. 2011;6:e19957.  Abstract
  • Gordy, C; Pua, H; Sempowski, GD; He, YW. Regulation of steady-state neutrophil homeostasis by macrophages. Blood. 2011;117:618-629.  Abstract
  • Jin, C; Shelburne, CP; Li, G; Potts, EN; Riebe, KJ; Sempowski, GD; Foster, WM; Abraham, SN. Particulate allergens potentiate allergic asthma in mice through sustained IgE-mediated mast cell activation. Journal of Clinical Investigation. 2011;121:941-955.  Abstract
  • Pastva, AM; Mukherjee, S; Giamberardino, C; Hsia, B; Lo, B; Sempowski, GD; Wright, JR. Lung effector memory and activated CD4+ T cells display enhanced proliferation in surfactant protein A-deficient mice during allergen-mediated inflammation. Journal of Immunology. 2011;186:2842-2849.  Abstract
  • Shi, X; Zhang, P; Sempowski, GD; Shellito, JE. Thymopoietic and bone marrow response to murine Pneumocystis pneumonia. Infection and Immunity. 2011;79:2031-2042.  Abstract