Role of cell cannibalism and non-canonical autophagy in antigen presentation: implications in T-cell selection and immune homeostasis
Lead Research Organisation:
University of Cambridge
Department Name: Biochemistry
Abstract
Theme: Bioscience for Health
Antigen acquisition and presentation is a vital part of the immune system which allows cells to distinguish self from non-self and mount a protective T-cell response against invading pathogens. Cells use a variety of mechanisms of acquiring antigens, involving the uptake of intracellular and extracellular material. This project will study the role of cell cannibalism in the acquisition and presentation of antigen in the context of T-cell selection. Cell cannibalism is a mechanism in which entire live cells are engulfed by other cells, resulting in the formation of cell-in-cell structures (1), and is a core interest of the Florey lab at the Babraham Institute (http://www.babraham.ac.uk/our-research/signalling/oliver-florey) . Examples of cell-in-cell structures are found in a variety of diseases (2, 3), but importantly also occur in physiological settings between thymocytes and epithelial nurse cells during T cell development in the thymus (4) and even between the embryo and uterus during implantation (5). In these examples, internalized cells can escape their engulfment, but more commonly their fate is death which involves the activation of a non-canonical autophagy pathway that promotes the lipidation of the protein LC3 to the vacuole housing the internalized cell (6-8).
This project will test the hypothesis that cell cannibalism can act as a route of antigen presentation and can be regulated by a non-canonical autophagy pathway. This would potentially have major implications in shaping the immune repertoire by controlling T cell selection and therefore participate in generating an immune system capable of responding to infection while maintaining immune tolerance.
The main aims will include the development and characterization of cell-cell interactions in model systems of cell cannibalism using microscopy based techniques. This will utilize existing cell cannibalism models of cultured human epithelial cells and the establishment of new models of primary mouse thymocytes interacting with a thymic nurse cell line. These systems will then be manipulated where by internalized cells are loaded with ovalbumin antigen, and subsequent presentation of antigen by hosts cells monitored using ovalbumin-specific T cells. Different aspects of cell-in-cell formation and fate will be manipulated to test for an effect on antigen presentation. The role of autophagy in cell-in-cell mediated antigen presentation will be tested using gene editing reagents developed by the lab that specifically inhibit non-canonical autophagy.
This project will combine immunology and cell biology expertise and provide a strong training in cell biology techniques, with an emphasis on microscopy, and molecular biology, including CRISPR/Cas9 gene editing. Expected results will have impacts on our understanding of how T cells are selected and the molecular pathways underlying this important homeostatic event.
Antigen acquisition and presentation is a vital part of the immune system which allows cells to distinguish self from non-self and mount a protective T-cell response against invading pathogens. Cells use a variety of mechanisms of acquiring antigens, involving the uptake of intracellular and extracellular material. This project will study the role of cell cannibalism in the acquisition and presentation of antigen in the context of T-cell selection. Cell cannibalism is a mechanism in which entire live cells are engulfed by other cells, resulting in the formation of cell-in-cell structures (1), and is a core interest of the Florey lab at the Babraham Institute (http://www.babraham.ac.uk/our-research/signalling/oliver-florey) . Examples of cell-in-cell structures are found in a variety of diseases (2, 3), but importantly also occur in physiological settings between thymocytes and epithelial nurse cells during T cell development in the thymus (4) and even between the embryo and uterus during implantation (5). In these examples, internalized cells can escape their engulfment, but more commonly their fate is death which involves the activation of a non-canonical autophagy pathway that promotes the lipidation of the protein LC3 to the vacuole housing the internalized cell (6-8).
This project will test the hypothesis that cell cannibalism can act as a route of antigen presentation and can be regulated by a non-canonical autophagy pathway. This would potentially have major implications in shaping the immune repertoire by controlling T cell selection and therefore participate in generating an immune system capable of responding to infection while maintaining immune tolerance.
The main aims will include the development and characterization of cell-cell interactions in model systems of cell cannibalism using microscopy based techniques. This will utilize existing cell cannibalism models of cultured human epithelial cells and the establishment of new models of primary mouse thymocytes interacting with a thymic nurse cell line. These systems will then be manipulated where by internalized cells are loaded with ovalbumin antigen, and subsequent presentation of antigen by hosts cells monitored using ovalbumin-specific T cells. Different aspects of cell-in-cell formation and fate will be manipulated to test for an effect on antigen presentation. The role of autophagy in cell-in-cell mediated antigen presentation will be tested using gene editing reagents developed by the lab that specifically inhibit non-canonical autophagy.
This project will combine immunology and cell biology expertise and provide a strong training in cell biology techniques, with an emphasis on microscopy, and molecular biology, including CRISPR/Cas9 gene editing. Expected results will have impacts on our understanding of how T cells are selected and the molecular pathways underlying this important homeostatic event.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/M011194/1 | 01/10/2015 | 31/03/2024 | |||
| 1804833 | Studentship | BB/M011194/1 | 01/10/2016 | 31/12/2020 | Katherine Sloan |
| Description | Non-canonical autophagy is a relatively novel cellular signalling pathway that is poorly understood. However, it can be described as a degradative pathway involving the breakdown of extracellular material that has been internalised. It is importance and functional significance is highlighted by its role in cancer, antigen presentation and vision. As a result of the work funded through this award, our understanding of non-canonical autophagy has been advanced. We have demonstrated that key autophagy proteins are recruited to compartments containing engulfed material and identified pathway specific post-translational modifications. |
| Exploitation Route | This work has contributed to our understanding of non-canonical autophagy and has generated promising preliminary data for further academic projects. |
| Sectors | Pharmaceuticals and Medical Biotechnology |
| Description | CAST Protein Challenge - School visit |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Schools |
| Results and Impact | Approximately 30 teenagers from a local college (Cambridge Academy Science Technology- CAST) chose to undertake our specific Protein Challenge as part of their academic course. We visited their school first to give a brief presentation on the project, and a month afterwards, they visited my lab to learn technical research skills. They were vocal and showed great interest specifically in the imaging facility. Following this, one girl from the group got in contact with me to ask if she could come for a week long internship in the laboratory group. |
| Year(s) Of Engagement Activity | 2018 |