5th International Workshop on Lung Health – Rising Stars Abstracts

For the 5^th International Workshop on Lung Health, a call for “Rising Stars” was launched in May 2017. The purpose of the competition was to offer to brilliant young researchers/clinicians the possibility to present their valuable work for the first time in front of an international audience, and also receive feedback of experienced international speakers to help them in their early carrier.

The call was open to researchers/clinicians up to 42 years old. To participate in the competition, they had to submit their abstract with a brief CV. Twenty abstracts were received from all over the World and were evaluated blindly by the five chairmen of the Workshop — the main criterion being the scientific value of the work presented in connection with the topics of the Workshop. Only in the case of equal scientific score, other parameters were considered to give priority to submitters from low-income countries or, in a second stage, to younger submitters.

The two winners, whose abstracts are given hereafter, have been invited as speakers to the Workshop and have had good visibility both thought the website and the Workshop newsletter.

In 2017, the winner were a young Italian researcher, accompanied by a young Colombian clinician working in Germany.

The participation of Rising Stars in the 5^th International Workshop on Lung Health was made possible

thanks to grants by Zambon S.p.A..

In April/May 2018 the call for Rising Stars will be open for the 6^th International Workshop on Lung Health to be held in Nice in January 2019.

Rising Stars Abstracts

Assessing inflammatory patterns in asthma endotypes:

new diagnostic and therapeutic perspectives

MatteoBradicich^1,2, Ian Pavord², Gareth Hynes², and Rahul Shrimanker²

¹Respiratory Pathophysiology and Rehabilitation Department, Cisanello University Hospital, University of Pisa, Pisa, Italy

²Respiratory Medicine Unit, Nuffield Department of Clinical Medicine, NDM Research Building, University of Oxford, Oxford, United Kingdom

Background

Bronchial asthma is a chronic airway disease affecting more than three hundred million patients worldwide. Given the high prevalence of this disease and the social and economic burden resulting from under- or mistreatment, the optimal management of this condition represents therefore a key goal. In order to investigate the pathophysiological heterogeneity of this disease, a rather new trend in the Literature suggests categorising different asthmatic patient subpopulations on the basis of their specific molecular patterns, which are supposed to represent the key pathological determinant leading to one particular group of symptoms and signs – i.e. a phenotype – rather than another one. Therefore, asthma endotypes are the key for understanding and treating asthmatic patients with a precision medicine approach.

Overview

A clinical study led by Oxford (United Kingdom) and Pisa (Italy) Universities quantifies the differences in the expression levels of multiple sputum inflammatory molecules between different subpopulations of asthmatic patients, previously labelled on the basis of their sputum differential cell count as affected by eosinophilic, neutrophilic, mixed, or paucigranulocytic asthma.

Methods

37 asthmatic patients and 12 healthy controls were recruited. Assessment of symptom burden and medication usage as well as laboratory measures including blood and sputum cell count and cytokine levels in sputum supernatant – measured using MSD® and Luminex® – was performed. The asthmatic patients were subdivided in four subgroups (eosinophilic, neutrophilic, mixed, and paucigranulocytic) on the basis of their sputum differential cell count. A comparison of the sputum concentration of the inflammatory molecules taken into consideration (IL-2, IL-4, IL-5, IL-8, IL-13, IL-17, IL-25, IL-33, PGD2, LTE4, TNF-α) between the aforementioned subgroups was subsequently carried out.

Results

The study shows that sputum IL-8, IL-17 and TNF-α are leading molecules in the neutrophilic asthma endotype, whilst sputum IL-5 and IL-33 underlie eosinophilic asthma. The mixed endotype is defined by high levels of sputum IL-5, IL-8 and IL-33. There are no significant results regarding paucigranulocytic asthma.

Conclusions

These pathophysiologic differences might be used in a compact, multi-cytokine assessment test that defines univocally the specific patient's inflammatory pattern from a single sample of induced sputum. Such results shed light on the multifaceted inflammatory environment in bronchial asthma and might promote further research in order to define new targeted therapy strategies for those patients with difficult-to-treat asthma.

Table 1. Results given as stated. FeNO, sputum IL-2, IL-4, IL-5, IL-8, IL-13, IL-17, IL-25, IL-33, LTE4, PGD2, TNF-α, blood eosinophils, blood neutrophils, sputum eosinophils, and sputum neutrophils did not conform to a normal distribution, therefore for these values the geometric mean (confidence interval in brackets) is presented. P-values listed for Kruskal-Wallis test comparisons between the endotype groups and the control group. SD – standard deviation; FeNO – fractional exhaled nitric oxide; ppb – parts per billion; np – not performable. Fixed airway obstruction is defined as a post-bronchodilator FEV1 absolute change <200 mL or a post-bronchodilator FEV1 increase <12%.

Table 2. Summary of the different cytokine expression patterns, clustered on the basis of a higher or lower sputum concentration observed in each endotype subgroup of the study. “+” represents a particularly high sputum concentration, while “-” represents a not particularly high/particularly low sputum concentration. Both these cut-offs need to be more precisely defined by further investigation. TNF-α: Tumour Necrosis Factor-α.

Circulating MDSC modulate IPF progression by orchestrating immunosuppressive and pro-fibrotic networks

Isis E. Fernandez¹, Flavia Greiffo¹, Marion Frankenberger¹, Jurgen Behr^2,3, Alistair Forrest⁴, and Oliver Eickelberg^1,5

¹Comprehensive Pneumology Center, Helmholtz Zentrum Munchen, Member of the German Center for Lung Research, Munich, Germany

²Asklepios Fachkliniken Munchen-Gauting, Munich, Germany

³Comprehensive Pneumology Center, Medizinische Klinik und Poliklinik V, Klinikum der Ludwig-Maximilians- Universität, Munich, Germany

⁴Harry Perkins Institute of Medical Research, QEII Medical Centre and Centre for Medical Research, the University of Western Australia, Perth, Australia

⁵Division of Respiratory Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Denver, USA

Rationale

Idiopathic pulmonary fibrosis (IPF) is a fibroproliferative lung disease with irreversible loss of lung function. Myeloid-derived suppressor cells (MDSC) are pathologically activated immature myeloid cells, which suppress immune responses in cancer, autoimmunity, and other inflammatory conditions. Recent literature supports that aberrant immune responses contribute to IPF pathogenesis. We reported, for the first time, that MDSC are increased in numbers, functionally active, and reflect disease status in IPF, in cross-sectional and longitudinal analysis serving as potent biomarker for IPF progression. Monocytic MDSC are the predominant subtype in IPF, and yet, differences between mature monocytes and monocytic MDSC, and their interaction in IPF have not been explored. Here we hypothesize that MDSC creates an immunosuppressive and pro-fibrotic environment in IPF, perpetuating disease.

Methods and results

We included 170 patients, including patients with IPF (n = 69), non-IPF ILD (n = 56), COPD (n = 23), and healthy controls (n = 22). We detected increased circulating MDSC in IPF compared to controls (30.99±15.61 vs 18.96±8.17%, p = <0.005), and a positive correlation between MDSC and FoxP3+ Tregs (r = 0.35, p = 0.04). In IPF, circulating MDSC inversely correlated with VCmax % predicted (r = -0.48, p = <0.0001). Correlation analysis of ΔVCmax with ΔMDSC, from visit 1 and 2, showed a strong correlation for longitudinally assessed IPF patients (r = -0.6052). The mRNA levels of the costimulatory signals during T cell activation (CD28, ICOS, ITK, and LCK) were significantly downregulated in PBMC, of IPF patient with high circulating MDSC. Next, using label-free quantitative MS-analysis, monocytes and MDSC isolated from human blood of 10 IPF patients were analyzed (MACS and FACS sorted, respectively). In total, we identified and quantified more than 7000 proteins. Principal component analysis unequivocally discriminated both cell types, showing that proteome differences between them are larger than the biological variations between the donors. Comparing the sets of proteins identified in the two cell types we found 502 MDSC enriched and 1224 monocyte enriched proteins (2 to >30 log10-transformed LFQ intensity ratios). Next, we examined the potential for these two cell types to communicate with each other, by identification of the receptors and ligands expressed by each, and considering known receptor-ligand interactions, compiled from published datasets. In the combined dataset 200 ligands and 153 receptors were detected. From the cell-to-cell communication analysis we identified both autocrine signaling edges from monocyte to monocyte (339), MDSC to MDSC (290), and paracrine signaling edges from monocyte to MDSC (311) and MDSC to monocyte (316). Specific ligands predicted to signal from monocyte to MDSC included: ANXA1, CCL18, CXCL2, HSP90AA1, ICAM1, TGFB2, amongst others. While ligands from MDSC to monocyte included: COL1A1, FN1, HLA-C, HSPG2, MMP1, S100A8-9, TGFB1, amongst others. Finally, FACS staining confirmed the surface expression of the cognate expressed receptors in both populations.

Conclusions

In summary, this study explores for the first time the MDSC proteome in fibrosis. We detected an increase in MDSC in peripheral blood from IPF patients. We further detected a correlation between MDSC and FoxP3+ T cells, and a decrease in the transcript levels of CD28, ICOS, ITK, and LCK in PBMC of IPF patients, suggesting that elevated MDSC might cause a blunted immune response. MDSC inversely correlate with lung function, as such MDSC may serve as potent biomarker for IPF progression. Using network analysis, our proteome data shows an autocrine and paracrine signals from and between monocytes and MDSC. MDSC signals include strong pro-fibrotic molecules, supporting a pro-fibrotic modulation. Furthermore, confirmation by flow cytometry of exclusively expressed surface receptors, might lead to identification of novel proteins useful for therapeutic targeting of MDSC and monocytes in IPF.