Study reveals how eosinophils play a protective role against Candida infections

New research shows that eosinophils, immune cells usually linked to allergies, also play a protective role against Candida infections by using the CD48 receptor to recognize the fungus and release proteins that stop its growth. This discovery is important because it reshapes how we understand the immune system and opens the door to new therapies that could strengthen natural defenses against life-threatening fungal infections, a growing challenge in hospitals worldwide.

A new study, conducted under the guidance of Prof. Francesca Levi-Schaffer from the School of Pharmacy at the Hebrew University and led by PhD candidates Ilan Zaffran, Prince Ofori, and postdoctoral fellow Pratibha Gaur, uncovers how a surprising player in the immune system, eosinophils, best known for their role in allergies and asthma, also helps protect the body against Candida albicans, one of the most common and dangerous fungal infections in humans.

Eosinophils are white blood cells typically associated with allergy, asthma, and inflammation. But their role in fighting infections has been less clear. The new research shows that these cells are not just bystanders: they can recognize and attack Candida albicans, a fungus that can cause life-threatening infections in people with weakened immune systems.

The study identifies CD48, a key receptor on eosinophils, as central to this defense. CD48 binds to a fungal surface protein known as Als6, helping eosinophils recognize and respond to infection. This interaction triggers the release of powerful proteins, including major basic protein 1 (MBP-1), that limit fungal growth and survival.

Invasive Candida infections are notoriously difficult to treat and remain a serious threat in hospitals worldwide. By showing that eosinophils, cells once thought to act mainly in allergies, also play a protective role, this research opens the door to new therapeutic strategies that could strengthen the body's natural defenses.

"This work changes the way we think about eosinophils," said the researchers. "Far from being only culprits in allergic disease, they may actually be allies in fighting dangerous infections."

By defining a new CD48-Als6 pathway, the study points to future possibilities for therapies that boost natural immunity. Harnessing the protective potential of eosinophils could one day improve treatment for patients vulnerable to invasive Candida disease.