Parasite Parcels

Parasites are like over-dedicated posties, refusing to let a locked gate stop them delivering their packages. When parasitic wasps deposit eggs directly into the body of fruit flies, they also deliver proteins designed to counter the host’s immune response. But how the larger of these are transported into host cells isn’t well understood. A study tracked venom after infection and observed the packaging of these damaging proteins into parcels called vesicles (red, pictured among fruit fly immune cells), which enter certain host immune cells (blue) to alter calcium levels and impair the immune response. The researchers also found that disrupting the integrity of these vesicles reduced the venom’s anti-immune capacity. Use of vesicles to smuggle virulence proteins is characteristic of many human-infecting parasites such as the malaria-causing Plasmodium falciparum, so developing our understanding of this transport mechanism could reveal new ways to prevent such unwanted deliveries.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image from work by Nicholas M. Bretz and colleagues
• Department of Biochemistry & Biophysics, Oregon State University, Corvallis, Oregon, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in PLOS Pathogens, October 2026