Regulation of immune checkpoint expression in human primary cells (360G-Wellcome-211681_Z_18_Z)

The host lab investigates post-transcriptional mechanisms that regulate expression of immune checkpoint membrane proteins in human primary dermal lymphatic endothelial cells (HDLECs) and dermal fibroblasts and recently demonstrated that PD-L1 is regulated by miR-155 (Yee et al., 2017, JBC). It has been suggested by others that resistance to therapeutic PD1 blockade is associated with alternative immune checkpoints in cancer cells, specifically the Gal9/TIM3 signalling axis. In this project, expression of Gal9 will be measured in unstimulated cells and cells treated with TNF and/or IFNg and upon over-expression or inhibition of miR-155. Experiments will be performed in both HDLECs and fibroblasts. Using already available small RNA sequencing data in the lab, miRNAs that can potentially suppress Gal9 expression and are significantly regulated upon treatment of HDLECs with TNF and IFNg will be identified. This will allow us to propose post-transcriptional regulatory networks that operate in non-transformed cells to control expression of a therapeutically relevant immune checkpoints. Training will include becoming familiar with cutting edge concepts in immunology and post-transcriptional gene silencing and techniques in primary cell culture and determining protein and mRNA expression, as well as extracting information from large transcriptomics datasets and using online in silico tools.