Treating metastatic disease through manipulation of regulatory T cells

Hughes, Ellyn 2017. Treating metastatic disease through manipulation of regulatory T cells. PhD Thesis, Cardiff University. Item availability restricted.

Preview	PDF (Thesis) Download (48MB) | Preview
	PDF - Supplemental Material Restricted to Repository staff only Download (357kB)

Abstract

CD4+Foxp3+ regulatory T cells (Tregs) are the main regulators of peripheral tolerance and prevent the development of fatal autoimmune disease in humans and mice. Furthermore, Tregs have also been implicated in suppressing anti-tumour immune responses and are often enriched at sites of primary and metastatic tumours. While studies have shown the effect of Treg ablation on the control of primary tumours, few studies have examined their contribution to metastasis progression. In this thesis I hypothesised that the depletion of Tregs could promote control over metastasis. To address this, a highly metastatic murine mammary carcinoma cell line 4T1 was injected into transgenic mice expressing the diphtheria toxin receptor in Foxp3+ cells. Foxp3+ cells were depleted by administration of diphtheria toxin and the impact of this on growth of primary tumours and metastases was assessed and measured in vitro clonogenic assays. Results of these experiments indicated that Tregdepletion led to control of primary tumour growth and in some mice to control of metastases. Control of metastases was linked to control of primary tumour growth. In order to measure metastasis in vivo, a PET/CT imaging technique was optimized. Primary tumours and large metastatic nodules were successfully imaged in mice using F18 FDG as a radiotracer. However, the studies described herein revealed that micrometastases in mouse lungs were too small to be reliably identified using PET data parameters. CT imaging did however enable detection of increases in tissue density within the lungs, which was suggestive of micrometastases. Data obtained in this way also indicated that Treg-depletion promotes control of metastasis in some mice. Collectively, the findings described in this thesis indicate that Tregdepletion can contribute to control of metastatic disease and should therefore represent an important component of novel immunotherapies.

Item Type:	Thesis (PhD)
Date Type:	Submission
Status:	Unpublished
Schools:	Medicine
Subjects:	R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology (including Cancer)
Funders:	Tenovus
Last Modified:	23 Apr 2021 09:36
URI:	https://orca.cardiff.ac.uk/id/eprint/103925

Actions (repository staff only)

Edit Item