Joints in Jeopardy

For thousands of different bacteria, the human body is their dream home. Take Staphylococcus aureus, a harmless tenant living on our skin until that is, it infects our joints, causing septic arthritis. In half of patients, this condition damages the bone to such an extent that they experience permanent joint dysfunction. Researchers investigate how this damage is caused by injecting the knees of mice with S. aureus lipoproteins (Lpps). A variety of immune cells infiltrated their joints: monocytes, macrophages and neutrophils. The team next depleted the mice of neutrophils and imaged their joints post-infection using micro-CT (pictured, middle), revealing greater bone damage compared to mice with a full complement of immune cells (left). In contrast, depleting the mice of macrophages and monocytes resulted in less bone damage (right), highlighting the opposing effects of different immune cells. Swaying the immune response in favour of neutrophils could prove useful in treating septic arthritis.

Written by Lux Fatimathas

Lux Fatimathas

Writer

Having pursued science through a career in research, communications and publishing, she is currently a writer and editor for a healthcare marketing agency and also juggles freelance science writing.

• Image from work by Majd Mohammad and colleagues
• Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
• Image originally published under a Creative Commons Licence (BY 4.0)
• Published in PLOS Pathogens, June 2019