Photographer Chanchal Sur Chowdhury
THIS microscopic image reveals some of the intricate defences employed by our immune system against infection. Titled Spiderman of Our Body and taken by Chanchal Sur Chowdhury, the shot was a shortlisted entry in the Royal Society of Biology’s 2021 Photography Competition.
When foreign particles or microorganisms enter the body, one of the first tactics deployed by the immune system is to try to destroy the invaders with neutrophils, a type of white blood cell. These cells, abundant in the bloodstream, travel to the site of infection and engulf the foreign agent before releasing enzymes to break it down and kill it.
Here, Chowdhury, who is at Washington University in Missouri, used scanning electron microscopy to capture neutrophils (shown in lighter blue) protecting against invading tuberculosis bacteria (pink). In a process called NETosis, the neutrophils release web-like DNA structures (yellow) known as neutrophil extracellular traps (NETs), which snare bacteria to prevent an infection spreading.
Malfunctioning NETosis has been linked to several infectious diseases, including covid-19. Too much NETosis, for example, plays a role in the development of “cytokine storms”, an excessive immune system response to a pathogen that can cause serious problems such as tissue damage.
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