Role of infiltrating neutrophils in tissue homeostasis

Project Information

TISSUENEU

Grant agreement ID: 748381

DOI

10.3030/748381

Project closed

EC signature date 17 March 2017

Start date 1 May 2017

End date 30 April 2019

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 158 121,60

EU contribution

€ 158 121,60

Coordinated by

CENTRO NACIONAL DE INVESTIGACIONES CARDIOVASCULARES CARLOS III (F.S.P.)
Spain

Periodic Reporting for period 1 - TISSUENEU (Role of infiltrating neutrophils in tissue homeostasis)

Reporting period: 2017-05-01 to 2019-04-30

Summary of the context and overall objectives of the project

Neutrophils are immune cells endowed with the capacity to infiltrate multiple tissues during inflammation to fight against pathogens. However, these cells continuously infiltrate most tissues also during steady state. Whereas several studies have addressed neutrophil biology in infiltrated tissues during pathological conditions, it is currently unknown how homeostatic infiltration of neutrophils modulates their behaviour and function and how this could affect the physiology of their targeted tissues. Tissueneu aim to explore neutrophil heterogeneity in tissues during homeostasis and to identify novel functions in these leukocytes that go beyond their role as immune sentinels.

Understanding neutrophils heterogeneity and its impact in tissue physiology is of the utmost importance because different types of neutrophils act as disease-modifying factor in several pathological conditions including cancer, stroke, myocardial infarction, autoimmune disease or tuberculosis. In this research project, we aim to provide a characterization of neutrophil heterogeneity and function during homeostasis. This information will provide a molecular and functional roadtrip of neutrophils biology during health that is currently missing, and will allow exploring how disease shape this heterogeneity and how this affect tissue homeostasis. Our final aim to identify the molecular mechanisms that modulate neutrophil diversity and to develop novel therapeutic approaches to fight disease.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In this research project we have isolated and characterized neutrophil states through different omics approaches in multiple tissues such as the bone marrow, spleen, lung, intestine and skin during homeostasis and we have explored neutrophil functions in silico using bioinformatics approaches and in vivo, studying the effect of neutropenia in normal tissue physiology.

Our results highlight a process of tissue imprinting of neutrophils in the steady state that can be detected even at the protein or RNA level. We characterized a previously undescribed remarkable transcriptional heterogeneity of these cells that accommodates to their target tissue and strongly predicts novel functions of these cells they leave the circulation, including vascular growth in the lungs and intestine. Our data suggest that tissular cues exploit neutrophil plasticity for the unique demands of each organ and indicate that neutrophil heterogeneity is important for normal tissue physiology.

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)

Despite established dogma considering neutrophils as homogeneous cells that have a limited immune role in fighting against pathogens, several studies suggest the neutrophils are in fact a heterogeneous cell population both in the steady state and in disease. We have characterized this heterogeneity and we have now strong evidences of tissue specification and function of neutrophils during steady state. We collected relevant transcriptomic data on several neutrophils populations and identified in silico potential molecular mechanisms that underlie neutrophil heterogeneity, makers for the identification of specific neutrophils subsets and targets for its modulation. All this knowledge will be used to study the detrimental or protective roles of neutrophil heterogeneity in diseases, such as cancer, myocardial infarct or autoimmunity

Neutrophils (green cells) patroling the healthy colon. Neurons (in red) and vessels (in cyan)