Autophagy regulation of stressed haematopoiesis

RUSHWORTH_U21DTP2

The ability of haematopoietic stem cells (HSC) to expand and differentiate is key to normal homeostasis and the systemic immune response.

HSCs promote a rapid immune response by generating innate and adaptive immune cells that are recruited to the site of infection. After the infection has been overcome HSC numbers decline to pre-infection levels, however what controls this reduction in numbers is not known. Our laboratory has shown that the non-haematopoietic cells (fibroblasts and adipocytes) support HSC maintenance in the bone marrow (BM) microenvironment. Others have shown that BM macrophages also support HSC expansion. However, the primary function of macrophages is phagocytosis (to engulf other cells, debris or microbes). Recently, a pathway called LC3-associated phagocytosis (LAP), which combines features of autophagy with phagocytosis, has been shown to be important in clearing cell debris. Here we hypothesise that LAP controls the reduction of HSC and progenitor cells in the BM after infection and that deficiencies in LAP allow for a dysfunctional HSC phenotype. Therefore, we aim to study the role of macrophage LAP on regulating the HSC pool in the BM microenvironment in response to infection and whether defective LAP leads to a dysfunctional immune response.

The PhD student will be trained in vivo techniques including animal handling, isolation of primary cells and techniques to assess functional characteristics of cells including FACS analysis, qPCR to analyse nucleic acids and western blot, ELISA and immunohistochemistry for protein analysis. This will give them a number of valuable transferrable skills which will help their scientific career progression. The project will be carried out at the Rushworth Lab based at the Bob Champion Research and Education building, Norwich Medical School, UEA, which combines research laboratories with medical training facilities. This work will be in close collaboration with the Powell Lab at Biomedical Research Centre, UEA.

References:

ROS-mediated PI3K activation drives mitochondrial transfer from stromal cells to hematopoietic stem cells in response to infection.Mistry JJ, Marlein CR, Moore JA, Hellmich C, Wojtowicz EE, Smith JGW, Macaulay I, Sun Y, Morfakis A, Patterson A, Horton RH, Divekar D, Morris CJ, Haestier A, Di Palma F, Beraza N, Bowles KM, Rushworth SA.Proc Natl Acad Sci U S A. 2019 Dec 3;116(49):24610-2461.

Rai S, Arasteh M, Jefferson M, Pearson T, Wang Y, Zhang W, et al. The ATG5-binding and coiled coil domains of ATG16L1 maintain autophagy and tissue homeostasis in mice independently of the WD domain required for LC3-associated phagocytosis. Autophagy. 2019 Apr;15(4):599-612