On The Trail of Deceptive Immune Cells Our immune system is designed to protect us from diseases. But why is it that our own defence cells can even aggravate some diseases such as cancer? This question interests biologist Dr Julia Lill. In January 2020, she began researching specialised immune cells of the innate immune response, the neutrophil granulocytes (neutrophils), in the BioFluorescence research group at ISAS. The scientist from Essen wants to understand what role these cells play in the microenvironment of a tumour and why they can sometimes even promote its growth. As a reaction to a tumour, the blood stem cells in the
Dr Julia Lill’s research at ISAS dealt with the immune response by neutrophil granulocytes.
bone marrow produce more neutrophils, which then enter the tumour. Instead of fighting it, the immune cells often develop tumour-promoting properties. For
develop suitable drug targets in the future. A specific
example, they can produce substances that help the
drug therapy could thereby block the tumour-promo-
abnormal cells make other immune cells, such as the T
ting properties of the neutrophils.
cells of the adaptive immune system (see info box), »fall
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asleep«. The result: the tumour can grow almost entirely
Neutrophils are relevant in many ways
unhindered. In order to understand this mechanism
Lill already investigated the body’s immune response
including its causes, Lill has compiled a data set of
through neutrophils for her dissertation, which she
3,500 involved proteins from neutrophils from the bone
completed in spring 2021 with the distinction summa
marrow, blood or tumour of mice, in order to identify
cum laude. Her work at the University Hospital Essen
the critical molecules. “When I look at the proteome
focused on so-called enterohaemorrhagic Escherichia
data, they tell me a story. I can see which proteins of
coli, better known as EHEC pathogens. They produce a
the neutrophils in the tumour are regulated differently
cell-damaging protein (shigatoxin) that can cause severe
compared to normal tissue,” reports the 28-year-old. On
inflammatory reactions in the body. Similar as in a
the basis of her data, researchers can find out which
tumour, the neutrophils can »overreact« and therefore
proteins they should examine more closely in order to
harm the body more than protect it.
ANNUAL REPORT 2021
