Department of Surgery

Hossam A. Abdelsamed, PhD

  • Research Assistant Professor

Dr. Abdelsamed's long-term vision is to develop a research program mainly focused on studying aging of the human immune system; specifically, understanding the effects of aging on memory CD8 T cell effector function through the lens of epigenetics, and then apply these basic mechanisms to enhance the outcome of solid organ transplantation. He is enthusiastic about applying cutting-edge molecular biology technologies, including epigenetics and CRIPSR/Cas9, to enhance the development of innovative approaches for the diagnosis of rejection and the prediction of organ transplant outcomes, including donor-specific tolerance.

Education & Training

  • Postdoctoral Research Fellowship, Immunology and Bone Marrow Transplantation, St. Jude Children’s Research Hospital
  • Postdoctoral Research Fellowship, Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center
  • PhD, Immunology, University of Tennessee Health Science Center
  • BSc (honors), Ain Shams University

Representative Publications

Dr. Abdelsamed's publications can be viewed on PubMed.

Research, Clinical, and/or Academic Interests

Dr. Abdelsamed’s research Interests include:

  • Epigenetic Regulation of Human Memory CD8 T Cells in Solid Organ Transplantation: One of the cardinal features of long-lived immunity is the development of cytotoxic memory CD8 T cells that can still remember our past history of infections. They are endowed by two fundamental characters: (1) maintenance of their effector function at steady state and (2) a rapid recall response upon pathogen re-exposure. However, they can behave similar to the main theme of duality found in the famous book “Strange Case of Dr. Jekyll and Mr. Hyde”. For instance, memory CD8 T cells that protect the host from pathogen re-exposure can start attacking a transplanted donor organ in the setup of solid organ transplantation. In this case, they “see” the donor’s organ as foreign and attack it, resulting in organ rejection. Consequently, the ultimate goal of solid organ transplantation is to induce donor-specific graft tolerance without compromising host protection against pathogens. However, it is clear that allo-reactive memory CD8 T cells are one major barrier against induction of graft tolerance. Hence, there is a critical need to understand the molecular mechanism(s) regulating the development and maintenance of human allo-reactive memory CD8 T cells. Since transcriptional regulation is mediated in part by epigenetic mechanisms, Dr. Abdelsamed’s research group approached the above-mentioned goal through the lens of epigenetics with a focus on DNA methylation.
  • Epigenetic Regulation of Human Memory CD8 T Cells During Immune Aging: The number of Americans aged 65 and older is projected to grow from 49.2 million in 2016 to over 94 million by 2060. Despite the increase in life expectancy, as we age our immune system reaches a state of immune senescence, resulting in susceptibility to a wide range of infections and impaired immune response to vaccines. Hence, it is crucial to define the molecular mechanisms regulating acquisition and maintenance of such impairment, which will ultimately allow us to develop strategies for rejuvenating the effector function of cytotoxic memory CD8 T cells in the elderly population.

Research Grants

  • Pittsburgh Liver Research Centre (PLRC) Pilot and Feasibility - University of Pittsburgh (PI: Abdelsamed). Epigenetic Effector programs of allo-reactive memory CD8 T cells in liver transplant patients, 9/2019 - 9/2020 (P30 DK1120531)

Faculty by divisions