Neutrophil and macrophage extracellular trap formation

Kidney grafts from deceased donors have inferior quality compared to grafts
from living donors. A large percentage of transplanted grafts are however from
deceased donors. Thus, finding strategies to improve the quality of organs from
deceased donors is crucial. During brain or circulatory death, the
pro-inflammatory environment primes the activation of various immune cells and
accordingly, increased leukocyte infiltration has been shown in grafts from
brain and circulatory dead donors. Neutrophils and macrophages can release
extracellular traps (ETS), a specific form of nuclear membrane disintegration
or blebbing that results in the release of chromatin, DNA and cytoplasmic
granules to the extracellular environment in response to specific stimuli.
These cells might therefore be involved in the tissue damage observed in
deceased donor grafts through the specific pathway of ET formation. During
brain or circulatory death, the endothelium is activated, while activated
platelets infiltrate grafts to participate in the formation microthrombi. It is
hypothesised that activated platelets and endothelial cells might be involved
in mediating the release ETs in deceased donor grafts. The project therefore
aims to determine whether the formation of ETs in grafts from deceased donors
are mediated by platelet and endothelial cell activation. In vitro assays with
isolated neutrophils, macrophages, platelets, and cultured endothelial cells
from kidney grafts or human umbilical cord endothelial cells stimulated with
pro-inflammatory cytokines will be performed to determine whether platelets and
the endothelium are mechanistically involved in ET formation. Knowledge gained
through the project could contribute to strategies aimed at improving the
quality of kidneys from deceased donors in a clinical setting.

-To investigate the development of ETs through the role of platelets and
activated endothelium by performing co-culture experiments with neutrophils,
macrophages, platelets and renal-derived endothelial cells.
-To determine whether deceased donor plasma stimulates ET release in isolated
neutrophils or macrophages.

In-vitro study

Participation in the study will involve the draw of a blood sample [20
millilitres (mL)] by a qualified medical practitioner at the UMCG during two
visits. Phlebotomy is normally done as part of routine medical care but may
present a slight risk and discomfort. This may result in a bruise at the
puncture site, or less commonly swelling of the vein, infection and bleeding
from the site.