Molecular regulation of neutrophil responses in inflammation

Project No: KTPS-NC-13
Intake: 2021 KTPS-NC

PROJECT Outline

Neutrophils exert anti-microbial activity through several mechanisms including release of cytotoxic products, reactive oxygen species (ROS), neutrophil extracellular traps (NETs) and pore-forming molecules (1). These activities cause tissue damage if poorly controlled. Our work confirmed that neutrophils play a central role in the initiation and perpetuation of aberrant immune responses and organ damage and that modulation of their numbers and functions leads to significant improvement in the pathogenesis of inflammatory arthritis and other forms of acute inflammation (2,3). Neutrophils are the most abundant cell type in the synovial fluid (SF) of rheumatoid arthritis (RA) patients, underlining their significant impact on immunopathology.

The signals and molecular mediators driving neutrophilic inflammation are not fully understood (4). We have recently developed a state-of-the-art genomic platform (5) to reveal transcriptional circuits that control neutrophil function and identified novel putative regulators that specifically modulated neutrophil development vs. inflammatory responses vs. survival. Decoding distinct transcription factor (TF) repertoires controlling neutrophil maturation or activation may lead to novel therapeutic strategies that benefit specific conditions. For example, inhibiting activation or specific effector functions of neutrophils may help to reduce the inflammatory burden suffered during inflammation-associated diseases, such as RA.

The aim of this project is to demonstrate that inflammation in arthritic joints can be reduced by targeting key molecular regulators of neutrophil maturation and/or a. The newly generated mouse models will be used during the DPhil project to validate the role of the identified key regulators in various neutrophil-driven inflammatory conditions in vivo. Specifically, we will assess the direct effects of deficiency or inhibition of specific TFs on neutrophil recruitment to the joint, effector functions (ROS production, NETosis, phagocytosis), inflammatory activity (cytokine production), and upstream molecular cascades using a combination of advanced genomic, epigenomic, immunological techniques, including cutting edge single cell technologies. We will test our hypotheses in murine arthritis models, in which we have previously outlined the importance of neutrophil recruitment to the joint (2,3). We will validate our findings in human blood and synovial fluid neutrophils.

The outcome of this study is expected to progress fundamental biology of neutrophils, increase our understanding of neutrophil activation in disease and aid the development of new targets for therapeutic interventions in inflammatory disorders, such as RA.

KEYWORDS

Neutrophils, inflammation, transcriptional regulators, genomics, mouse models, clinical samples

TRAINING OPPORTUNITIES

The Kennedy Institute is a world-renowned research centre and is housed in a brand new state-of-the-art research facility. Training will be provided in techniques in a wide range of functional genomics approaches (RNA-Seq, ATAC-Seq, ChIP-Seq), immunological (cell isolation, tissue culture, FACS), and imaging (immunofluorescence on tissue sections) approaches, as well as cutting edge single cell platforms (10x, CyTOF) and computational pipelines. Recently developed novel in vivo models of inflammatory diseases will be extensively used and new models will be generated. The candidate can benefit from the hands-on experience with these techniques in the Udalova lab, and from access to clinical samples and expertise in their immune analysis in the Luqmani lab. A core curriculum of lectures will be taken in the first term to provide a solid foundation in a broad range of subjects including musculoskeletal biology, inflammation, epigenetics, translational immunology and data analysis. Students will attend weekly seminars within the department and those relevant in the wider University. Students will be expected to present data regularly to the department, the Genomics of Inflammation lab and to attend external conferences to present their research globally. Students will also have the opportunity to work closely with members of the Rheumatoid Arthritis Pathogenesis Centre of Excellence (Glasgow/Birmingham/Newcastle/Oxford), as well as Novonordisk Immunometabolism consortium (Oxford/Karolinska Institute/University of Copenhagen).

KEY PUBLICATIONS

Ng LG, Ostuni R, Hidalgo A. Heterogeneity of neutrophils. Nature Reviews Immunology. 2019, 19(4):255-265.
Weiss M, Byrne AJ, Blazek K, Saliba DG, Pease JD, Perocheau D, Feldmann M, Udalova IA. IRF5 controls both acute and chronic inflammation. Proceedings of the National Academy of Sciences. 2015, 112(35):11001-6.
Blazek K, Eames HL, Weiss M, Byrne AJ, Perocheau D, Pease JD, Doyle S, McCann F, Williams RO, Udalova IA. IFN-lambda resolves inflammation via suppression of neutrophil infiltration and IL-1b-production. Journal of Experimental Medicine. 2015, 212(6):845-53.
Ai Z, Udalova IA. Transcriptional Regulation of Neutrophil Differentiation and Function During Inflammation. Journal of Leukocyte Biology. 2020, 107(3):419-430.
Saliba DG, Heger A, Eames HL, Oikonomopoulos S, Teixeira A, Blazek K, Androulidaki A, Wong D, Goh FG, Weiss M, Byrne A, Pasparakis M, Ragoussis J, Udalova IA. IRF5:RelA interaction targets inflammatory genes in macrophages. Cell Reports. 2014 Sep 11;8(5):1308-17.