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  • Project No: #OxKEN-2021/17
  • Intake: OxKEN

PROJECT OVERVIEW

Giant cell arteritis (GCA) is the most common form of vasculitis, which affects mainly the aging population leading to permanent blindness without timely diagnosis and medical intervention (1). GCA patients are 17 times more likely to develop cardiovascular complications compared to the healthy controls. Similar cardiovascular commodity is also observed in other rheumatic diseases including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and ANCA (anti neutrophil cytoplasmic antibody) associated vasculitis (2).

However, the underlying pathogenesis of GCA remains poorly understood. we have recently discovered novel immature neutrophils populations in the blood of GCA patients to be unequivocally associated with both the clinical phenotype and response to treatment (3) Moreover, the release of immature neutrophils into the circulation has been described in SLE, RA, and infectious diseases, such as sepsis or severe COVID-19 (5). We further demonstrated that immature neutrophils remained in the vasculature for a prolonged time, interacted with platelets, extravasated into the tissue surrounding the temporal arteries and generated high levels of extracellular reactive oxygen species (ROS) affecting vascular barrier in vitro (3).

Based on our findings, we hypothesize that immature neutrophils are the key players in initiating vascular inflammation and propose the following 3-stage model of neutrophils in GCA pathogenesis. Stage 1: ongoing chronic inflammation in patients causes release of immature neutrophils into the circulation with an extended life span. Stage 2: immature neutrophils enter from both lumen and capillaries and adhere to the elastic lamina for prolonged periods of time to release ROS in an inflammatory microenvironment, which results in the accumulation of small breaks and lesions in elastic lamina. Stage 3: other immune cells, including monocytes, T cells, and DCs, infiltrate into the vessels via the initial lesions and gradually lead to formation of giant cells and/or granulomas culminating in severe vessel inflammation. Specifically, disbalance in T cell repertoire, i.e. expansion of Th1 and Th17 cell and reduction in Treg cells, has been well-documented in GCA patients (2). This project will investigate the interaction between immature neutrophils and dysfunctional T cells and its contribution to the GCA pathogenesis.

The study will be conducted in three key stages.

S1) Mapping the geographical distribution of neutrophils and T cells subsets and their direct physical cell interaction in the biopsies of newly diagnosed GCA patients (4) using Hyperion, imaging mass cytometry of up to 40 markers.

S2) Immunophenotyping T cell subsets in the blood of GCA patients using CyTOF and FACS analyses.

S3) In vitro analysis of neutrophil and T cell interactions, such as T cell proliferation assay in the presence of neutrophils; b) profiling of growth factors and cytokines released by neutrophils and T cells, which sustain proliferation, recruitment etc.

Insight from studying neutrophil and T cell interplay in GCA will aid discovery of new molecular mechanisms behind inflammatory vasculature diseases and may lead to alternative neutrophil – T cell targeted therapies.

KEYWORDS

Giant cell arteritis, vascular inflammation, neutrophils, t cells, hyperion

TRAINING OPPORTUNITIES

The candidate will benefit significantly from the established and productive framework of translational medical research between the Udalova and Luqmani groups based at Kennedy institute and Botnar research centre respectively. The Kennedy Institute hosts state-of-art core research facilities from single cell mass cytometry (CyToF), imaging mass cytometry (Hyperion), FACS sorting to advanced imaging technologies including confocal, whole tissue and live cell imaging.  The candidate will be trained to acquire those advanced cellular technologies which offer unprecedented potential to tackle challenging biomedical questions. The Botnar team lead by Professor Luqmani will provide training on the design of biomedical research, analysis of large medical dataset and organisation of clinical sample recruitments and processing.

The candidate will learn basic molecular techniques at the Udalova group including human blood PBMC isolation; cell purification, isolation and ex vivo tissue culture; western, ELISA and rt-PCR. A rare opportunity associated with the proposed project is to establish a 3D microvessel culture to model the interaction between neutrophils and t cells in GCA pathogenesis. The 3D cell culture on-a-chip system can be modified and adapted to other organoid systems in a high throughout format that will be very useful for disease target identification and drug screening in medical research.

The project will be in active collaboration with other groups of various expertise in and outside Oxford. For instance, multiplex luminex in collaboration with Luzheng Xue group at Nuffield department of medicine will be conducted to investigate growth factors and cytokines released by neutrophils in vitro and in the plasma of GCA patients. Hyperion will be in collaboration with Ling-pei Ho group at WIMM.

Scientific writing, data analysis and communication skills are an integral part of the D.Phil program. The candidate will be required to present and attend lab meetings, encouraged to attend both external and internal Kennedy seminars and journal clubs, relevant workshops on cutting edge technologies, data analysis tools/software and to present at local and national conferences related to the proposed program. Discoveries made from the research will be highly encouraged to be published at high impact journals.

KEY PUBLICATIONS

  1. C. Ponte, A. F. Rodrigues, L. O'Neill, R. A. Luqmani, Giant cell arteritis: Current treatment and management. World J Clin Cases 3, 484-494 (2015)
  2. D. M. Schwartz, A. M. Burma, M. M. Kitakule, Y. Luo, T cells in autoimmunity-associated cardiovascular diseases. Front. Immunol. 11: 588776 (2020)
  3. L. Wang et al., ROS-producing immature neutrophils in giant cell arteritis are linked to vascular pathologies. JCI Insight 5, (2020).
  4. R. Luqmani et al., The Role of Ultrasound Compared to Biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis (TABUL): a diagnostic accuracy and cost-effectiveness study. Health Technol Assess 20, 1-238 (2016).
  5. A. Silvin et al., Elevated Calprotectin and Abnormal Myeloid Cell Subsets Discriminate Severe from Mild COVID-19. Cell 182, 1401-1418 e1418 (2020).

CONTACT INFORMATION OF ALL SUPERVISORS

Professor Irina Udalova

Professor Raashid Luqmani