Mohammad Heidarian successfully defended his M.S. thesis this past March and completed the Pathology M.S. program. Mohammad’s thesis is entitled Sublethal Whole-body Irradiation Induces Permanent Loss and Dysfunction in Pathogen-specific Circulating Memory CD8 T Cell Populations. He performed his thesis work in the laboratory of Dr. Vladimir Badovinac where he examined the effects of irradiation on the memory CD8 T cell compartment.
Incidental or deliberate exposure of individuals to high levels of ionizing radiation is still a viable threat and a complicated public health issue. While the depleting effects of ionizing radiation on immune cells are established and clinically exploited for procedures that require rapid immune system suppression, the long-term impact of sublethal ionizing radiation on preexisting memory CD8 T cells remains unclear. Mohammad demonstrated that in addition to rapid loss of circulating memory CD8 T cells, ionizing radiation leads to a lasting lesion which prevents the surviving circulating memory CD8 T cells from numerically and functionally recovering. The long-lasting diminished number and function of circulating memory CD8 T cells lead to compromised protection of once-immunized irradiated hosts. These findings are a critical first step in development of treatments that aim to curb radiation-induced immunosuppression with high efficacy. In addition to Dr. Badovinac, Drs. John Harty and Kevin Legge served on his committee.
Importantly, the results of Mohammad’s thesis were recently published in the Proceeding of the National Academy of Sciences. The paper can be viewed at: