Project 466653

The proposed project centres around a group of immune cells called Mucosal-associated invariant T (MAIT) cells. Even though these cells make up a sizeable portion of all T cells in the human immune system, they have not been extensively studied. MAIT cells are known to interact with the commensal bacteria, or microbiota, that naturally exists in the body. Furthermore, previous studies have shown how alterations in the microbiota can affect tumour development. However, even though MAIT cells have been found in the tumour environment, their role in this dynamic has remained unexplored. The hypothesis is that MAIT cells are the link between the microbiota and its apparent effects on tumour progression. Therefore, the main objective of this project is to use a mouse model to characterize the relationship between MAIT cells and the microbiota, and explore how this relationship may affect tumour progression and treatment. To accomplish the first portion, MAIT cell activity will be compared between normal mice and mice with an altered microbiota. The experiment will then be repeated, with the addition of injecting tumours into the mice to compare growth between the groups. Finally, to explore responsiveness to treatment, the experiment will be replicated with the inclusion of a tumour treatment called anti-programmed cell death 1 (PD1) therapy. It is predicted that by altering the microbiota in mice, MAIT cell populations will be affected and subsequently, tumour growth and response to anti-PD1 therapy will differ. This work has the potential to change how we treat certain types of cancerous tumours. With more knowledge of this relationship, the microbiota and/or MAIT cells could become targets for future cancer therapies.