Supervisor:
Program of Study:
PhD, Biochemistry
Project Title:
The role of extracellular vesicles in B cell function and development
Scholarships and/or Awards:
-
- L. Jacobs Graduate Research Award 2023
-
- Mitacs Accelerate PhD Fellowship Award, 2021-2023
-
- Barrowman Travel Award, 2021-2022
-
- Barrowman Travel Award, 2020-2021
-
- VIED overseas graduate scholarship, 2018-2020
-
- NPUST International Development scholarship for MSc, 2013-2015
Lay research summary:
Extracellular vesicles (EVs) are nanosized, membrane-encapsulated particles secreted from almost all cells. They carry bioactive cargo, such as genetic material, lipids, and proteins, and they are taken up by recipient cells. CD24 is a small protein connected to the plasma membrane in many cells. Several studies indicate that CD24 acts as a “do not eat me” signal to protect cancer cells. We also found that stimulation of CD24 on murine B lymphoma cells causes the release of EVs transferring lipid and membrane proteins to recipient cells. This exchange can regulate the extracellular microenvironment by inducing apoptosis in recipient bystander B cells. Our finding suggests that EVs can change the functional biology of surrounding cells, which may impact B cell development and the tumor microenvironment. However, it is not clear how EVs form in response to CD24 activation. Thus, current efforts are focused on learning the mechanism generating EV release in response to CD24. Regulating EV release may help to regulate the tumor microenvironment to affect cancer treatment.
Career Aspirations:
Following completion of my PhD degree in Biochemistry, I plan to pursue a Postdoc in immunology. My career goal is to become a scientist.
Location:
Memorial University of Newfoundland
Publications:
Hong-Dien Phan, Delania J.B. Gormley, Reilly H. Smith, Modeline N. Longjohn, May Dang-Lawson, Linda Matsuuchi, Micheal R. Gold, Sherri L. Christian. CD24 and IgM stimulation of B cells triggers transfer of functional CD24 and B cell receptor to B cell recipients via extracellular vesicles. 2021. Journal of Immunology, 207 (12): 3004-3015.
Modeline N. Longjohn, Hong-Dien Phan, Sherri L. Christian. Chapter 2: Culturing suspension cancer cell lines. 2022. Springer Nature. Cancer cell Biology: Methods and Protocols, Methods in Molecular Biology, Vol. 2508.
Recent news:
We discovered an unknown mechanism of EV release that CD24 mediates ASMase, which triggers the PI3K/mTORC2/actin pathway to release ectosomes budded off the plasma membrane. However, it is unknown if this pathway regulates ectosome release in other cell types in response to different stimulations. In brief, our findings have identified a novel pathway that governs ectosome release.