Investigating immune-epithelial cells in patients with cystic fibrosis

The major focus of cystic fibrosis (CF) research has been on CF transmembrane
conductance regulator (CFTR) ion channel dysfunction and how it deregulates
epithelial cell biology. The broader role of the immune system in this context
has received less attention, despite the importance of cellular crosstalk
between epithelial cells and immune cells to regulate each other's function. CF
patients suffer from recurring immune cell activation and chronic inflammation,
which can have a major impact on epithelial dysfunction and vice versa. We
hypothesize that a better understanding of the nature of the chronic
inflammation and the epithelial-immune cell dialogue in CF will yield new
insights into disease pathophysiology - including leads for new therapeutic
interventions.

The primary objective of this study is to characterize the immune cell
composition and epithelial-immune cell crosstalks in patients with CF. The
endpoint will be constituted from several read-outs on peripheral blood
mononuclear cells (PBMC's), sputum, bronchoalveolar lavage (BAL) and
endobronchial biopsies.

This is a observational study in patients with CF. During regular out-patient
clinic visits, in addition to regular blood and sputum samples as part of
standard care, additional blood, sputum and nose brush samples will be
collected from included patients once. Additionally, patients will be asked to
undergo a bronchoscopy to collect BAL and endobronchial tissue samples. The
additional blood, sputum, BAL and endobronchial biopsies will be analyzed by
flowcytometry (BD Symphony system with up to 30 protein markers per cell),
imaging mass cytometry (Hyperion system with up to 37 protein markers on
histological samples) and single cell transcriptomics (10x Genomics 3* v.3.1
mRNA-seq with on average ~5000 genes detected per cell). These
multi-dimensional read-outs of the lung tissue microenvironment in CF patients
will allow us to construct a cellular atlas of the epithelial and immune cell
biology in the CF lung. Patients will be enrolled from the 1st of April 2021
until 1st of April 2025.

After informed consent, peripheral blood and sputum will be collected once
during routine outpatient visit. Peripheral blood will be collected by means of
vena puncture. Vena puncture can cause mild discomfort; the puncture could be
experienced as being painful, and a hematoma could result from this procedure.
There are no further risks associated with participation.

No risks are associated with sputum collection.

Nose brush collection could cause mild discomfort, which disappears very
quickly. No risks are associated with nose brush collection.

Bronchoalveolar lavage (BAL) and endobronchial biopsies will be obtained
through bronchoscopy during an additional outpatient visit. Bronchoscopy with
lavage and collecting endobronchial biopsies is a well tolerated routine
procedure that can be safely performed on a outpatient basis. Adverse events
related to bronchoscopy are rare and the lethality is below 0.01%. common
adverse events are pneumonia, bleeding, heart arrhythemias and pneumothorax.
Although subjects will not have direct benefit from findings in this study,
their contribution will be of great value for improving our understanding of
the role of the immune system in CF disease pathophysiology. In the future,
these insights could lead to the development of new therapies that will benefit
CF patients.