Inflammation Probe

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The Problem

Some lung diseases can cause ‘inflammation’, a protective response generated by the body in retaliation to damage to tissue caused by injury and illness. It clears away dead cells and starts the repairing process.

Two examples of where inflammation is related to lung disease are:

  1. Acute Respiratory Distress Syndrome (ARDS), where inflammation brought about by infection or injury causes fluid from nearby blood vessels to leak into the tiny air sacs of the lungs. This leads to potentially life-threatening low oxygen levels in the blood, and makes breathing difficult.
  2. Pneumonia, as a result of bacterial infection, can lead to inflammation of the tissue in one or both lungs, and may cause fluid to leak into the tiny air sacs.

It is therefore important that clinicians can quickly identify the sites of inflammation in order to treat them effectively.

The Solution

Tiny amounts of chemical SmartProbes will be sprayed into the deepest parts of the human lung, emitting light (‘fluorescence’) in the presence of a particular ‘inflammation’ enzyme – a protein made by the body that brings about a specific chemical reaction. The fluorescence is then detected using tiny fibre optic tubes that are inserted deep into the patient’s lung through a bronchoscope, and shown on a screen at the patient’s bedside within a couple of minutes.

The Method

The Neutrophil Activation Probe (NAP) is a Smartprobe that fluoresces when it comes into contact with elastase, an enzyme that exists inside a type of immune cell called a ‘neutrophil’, when the neutrophil is activated in inflammation.

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A diagram showing the internal structure of a neutrophil, highlighting granules and a segmented nucleus
3D rendered image credit: Bruce Blaus (2014) ‘Medical Gallery of Blausen Medical 2014’, WikiJournal of Medicine.

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Neutrophils are a type of white blood cell that are part of the body’s first line of defence against infection. Inside neutrophils are small granules that release enzymes when ‘activated’, designed to kill invading microorganisms. Elastase exists inside these granules. Neutrophils can also ingest microbes, other cells and foreign particles.

A unique feature of immune cells like neutrophils that have segmented nuclei is that they can eject their DNA to create a sticky net called a ‘Neutrophil Extracellular Trap’ (NET), which traps and kills foreign bodies in the blood. This process is called NETosis, during which the neutrophil is also destroyed.

The result of these attack mechanisms against intruders is inflammation in the affected area. Therefore, by using the NAP Smartprobe, clinicians will be able to directly see sites of inflammation in the body by highlighting where the neutrophils are.

A photo of neutrophils taken on a micrograph
A photograph of neutrophils fighting inflammation taken through a microscope.
Image credit: Calicut Medical College
This video was created by Ellie Cawthera, with contributions from Hannah Stewart and Caroline Lyth
(MSc Science Communication and Public Engagement at the University of Edinburgh)
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The music ‘Fermons Une Plage’ by Monplaisir is licensed under a CCO 1.0 Universal License