Periodic Reporting for period 2 - Host-TB (Using CRISPR genome screens and dual transcriptome analyses to dissect host-pathogen interactions in tuberculosis)
Reporting period: 2020-12-01 to 2022-05-31
With more than 10 million cases annually, tuberculosis (TB) remains a global health problem. TB epidemic is exacerbated by the spread of multidrug-resistant TB. Host-directed therapies can improve immune mechanisms by augmenting the ability of host cells to kill M. tuberculosis bacilli or by modulating the immune response to prevent excessive inflammation, cell death and tissue damage in the human body. Progress with the development of new host-directed therapies has been slowed down by the limited understanding of host-pathogen interactions during M. tuberculosis infection. Screens of the whole human genome can identify novel genes involved in the immune responses to M. tuberculosis infection and susceptibility to TB. Previously, we successfully used genome-wide association studies to identify human genes associated with susceptibility to TB. Here, we will use the groundbreaking CRISPR technology to screen the human genome in macrophages infected with M. tuberculosis and discover genes that are critically involved in host-pathogen interactions. Then, we will comprehensively characterise cellular signalling pathways that mediate impacts of these genes on both the human macrophage and the intracellular bacilli using dual transcriptome analyses and high-throughput microscopy assays. This novel approach will dissect crucial mechanisms of host-pathogen interaction during M. tuberculosis infection.
Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far
We performed the screens of human genome in CRISPR-Cas9-edited macrophages after their infection with M. tuberculosis. These screens revealed several genes that regulate death of human macrophages during infection.
Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)
The novel human genes that affect susceptibility of macrophages to M. tuberculosis infection will be now validated in the follow-up experiments. Details of the mechanism of macrophage death will be thoroughly characterised for each of the newly identified genes and the role of virulence factors of M. tuberculosis will be also studied. Proteins encoded by these genes and their signalling pathways may provide novel targets for host-directed therapy of tuberculosis.