▶Subject: T cell differentiation during chronic infection and cancer: Implications for immunotherapy
▶Speaker: Se Jin, Im, Ph.D. (Department of Microbiology and Immunology, Emory University)
▶Date: 4:00PM/Jun. 24(Mon.)/2019
▶Place: Auditorium(1F), Postech Biotech Center
Chronic viral infections and cancer are characterized by a state of T cell dysfunction that is associated with expression of the programmed cell death 1 (PD-1) inhibitory receptor. A better understanding of the mechanisms that regulate CD8 T cell responses during chronic viral infection and cancer is required to improve immunotherapies that restore function in exhausted CD8 T cells. I have recently identified a novel population of CXCR5+TCF1+ virus-specific CD8 T cells that act as stem cells to maintain T cell responses during chronic infection of mice with lymphocytic choriomeningitis virus (LCMV). These stem-like CD8 T cells underwent a slow self-renewal and could also differentiate into the terminally differentiated CD8 T cells. In addition, these stem-like cells displayed distinct phenotypic, transcriptomic, and epigenetic signatures from terminally differentiated CD8 T cells. Notably, the transcription factor TCF1 was indispensable for the generation of stem-like CD8 T cell subset. Most importantly, the proliferative burst of T cells that is seen after PD-1 blockade came almost exclusively from this stem-like CD8 T cell subset. I also identified a subset of CD8 tumor-infiltrating lymphocytes (TILs) showing similar features to stem-like CD8 T cells in solid murine tumor models and in human non-small cell lung cancer and possessing a proliferative potential after antigenic stimulation. These findings provide a better understanding of T cell exhaustion and have implications in the optimization of PD-1-directed immunotherapy in chronic infections and cancer.
▶Inquiry: Department of Life Sciences (Tel. 279-2721)
* This seminar will be given in English.
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