Shear stress in microfluidics: avidity-based selection of T cell and natural killer cells & mechanical activation of pancreatic stellate cells
File(s)
Author(s)
KC, Neelima
Type
Thesis
Abstract
This thesis examines how shear stress in microfluidics technology influences cell behaviour, particularly in T cells, Natural Killer (NK) cells, and mechanobiology of pancreatic stellate cells (PSCs) in Pancreatic ductal adenocarcinoma (PDAC).
The activation of T cells relies on integrin binding and co-stimulatory signals, with the strength of these connections impacting their functions. In Chapter 2, a microfluidic approach using shear stress successfully isolates T cells based on their avidity to melanoma cells, showing that higher avidity is associated with greater cytotoxic activity. This is further illustrated through patient-derived TCR-T cell models, which maintained their functional characteristics after isolation.
Chapter 3 applies the technology to NK cells, demonstrating that they can also be sorted according to their avidity. The findings indicate that enhancing activation receptors boost avidity, which aligns positively with NK cell cytotoxicity, whereas enhancing inhibitory receptors yields the opposite effect. This marks a novel application of shear stress for isolating NK cells based on their binding strength. Furthermore, the avidity profile of CAR-iNKT (invariant natural killer T) cells aligned with cytotoxicity in-vivo.
In the fourth chapter, the research explores how shear stress and constriction affect PSCs, which are significant contributors to pancreatic cancer. The study shows that a shear stress of 1.9 Pa and a constriction of 10 µm can activate PSCs, as evidenced by increased smooth muscle actin-alpha expression. This suggests that PSCs circulating in the bloodstream, whether activated or not, can become fully activated under specific hemodynamic conditions.
Overall, the findings highlight the potential of microfluidic technologies for guiding personalised immune therapies and furthering our comprehension of PSC activation mechanisms in cancer contexts.
The activation of T cells relies on integrin binding and co-stimulatory signals, with the strength of these connections impacting their functions. In Chapter 2, a microfluidic approach using shear stress successfully isolates T cells based on their avidity to melanoma cells, showing that higher avidity is associated with greater cytotoxic activity. This is further illustrated through patient-derived TCR-T cell models, which maintained their functional characteristics after isolation.
Chapter 3 applies the technology to NK cells, demonstrating that they can also be sorted according to their avidity. The findings indicate that enhancing activation receptors boost avidity, which aligns positively with NK cell cytotoxicity, whereas enhancing inhibitory receptors yields the opposite effect. This marks a novel application of shear stress for isolating NK cells based on their binding strength. Furthermore, the avidity profile of CAR-iNKT (invariant natural killer T) cells aligned with cytotoxicity in-vivo.
In the fourth chapter, the research explores how shear stress and constriction affect PSCs, which are significant contributors to pancreatic cancer. The study shows that a shear stress of 1.9 Pa and a constriction of 10 µm can activate PSCs, as evidenced by increased smooth muscle actin-alpha expression. This suggests that PSCs circulating in the bloodstream, whether activated or not, can become fully activated under specific hemodynamic conditions.
Overall, the findings highlight the potential of microfluidic technologies for guiding personalised immune therapies and furthering our comprehension of PSC activation mechanisms in cancer contexts.
Version
Open Access
Date Issued
2024-07-21
Date Awarded
2025-01-01
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Au, Sam
Sponsor
Imeprial College London
Publisher Department
Bioengineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)