Scientist Profiles - Howard Petrie

Howard Terrence Petrie, Ph.D.
Professor,
Department of Cancer Biology
Director, Flow Cytometry Core

As a full Professor of The Cancer Biology Department at Scripps Florida, Howard Petrie focuses on the production of specialized blood cells called T lymphocytes, which are central mediators of the immune response. Understanding this is essential in developing treatments for immunodeficiencies resulting from environmental exposure (such as HIV/AIDS) or aging.  Targets that Dr. Petrie has identified are activated in several cancers that affect women, specifically ovarian and breast cancer, and in leukemia.

Dr. Petrie, a native of Pennsylvania, received both his Bachelor of Science (1978) and Master of Science (1981) degrees, with majors in microbiology, from Pennsylvania State University, in University Park, Pennsylvania. He earned his Ph.D. in Medical Sciences from the University of Nebraska Medical Center in Omaha in 1988. He then completed a four-year postdoctoral fellowship in the Lymphocyte Differentiation Unit of the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia, followed by a two-year postdoctoral fellowship in the Section of Immunobiology at Yale University School of Medicine in New Haven, Connecticut.

From 1993 to 2004, he was an Assistant Member, then Associate Member, of the Sloan-Kettering Institute in New York City.  In 2004, he was appointed as a Professor in the Department of Microbiology and Immunology at the University of Miami, Miller School of Medicine.   In 2005, he was recruited to join the faculty at Scripps Florida where he is a Professor in the Department of Cancer Biology and is Director of the Flow Cytometry Core.

Dr. Petrie is a renowned specialist in the study of the processes that induce bone marrow stem cells to differentiate into T lymphocytes throughout the course of life. T lymphocytes can be lost from the body for a variety of reasons, including bleeding, aging, infection, or chemotherapy drugs.  These lost cells must be replaced, and deficiencies in this process can result in life-threatening susceptibility to infection, particularly by viruses. His work focuses on understanding how T lymphocyte production occurs under normal circumstances, and how these go awry in diseases such as immunodeficiency and leukemia. The Petrie lab focuses on T-cell development, aging, and cancer and the Notch 3 target that he has identified as being important for T-cell development and that is directly activated in ovarian cancer and breast cancer in women.

In 2009, Professor Petrie received a pair of grants from the National Institutes of Health (NIH) worth a total of $4.3 million dollars over five years. The first grant supports studies of how the gene Notch 3 controls the development and production of T lymphocytes, and then attack infectious agents as well as cancer cells. Petrie’s goal is to understand how Notch 3 normally prevents this aging of the immune system, and how Notch 3 functions in general in blood cells, as well as in other tissue types.  The second grant supports Dr. Petrie’s work understanding regrowth of the thymus in adults and the elderly. Using an experimental model of thymus regrowth, Dr. Petrie and his colleagues will seek to identify the changes in gene expression that occur after induction of regrowth, and to recapitulate these through pharmaceutical approaches for thymus regeneration therapy.

He has served in various editorial positions at The Journal of Immunology, Clinical and Developmental Immunology, and Seminars in Immunology. Dr. Petrie is also a regular consultant for the NIH.