A team of Eindhoven- en Nijmegen-based scientists explains in Nature Biomedical Engineering how they succeeded in targeting interleukin-4 to immune cells in the spleen and bone marrow. That offers the prospect of a therapy against sepsis and other life-threatening conditions associated with hyperinflammation and immunoparalysis.  

Interleukins regulate the immune response through either pro- or anti-inflammatory activity. Thus, anti-inflammatory interleukins are expacted to have a dampening effect on trained immunity, also known as the ‘memory’ of our innate immune system. Thanks to this relatively recently discovered phenomenon, first described by professor Mihai Netea of the Radboud University Medical Center in Nijmegen (The Netherlands), the innate immune system remains on standby after a first trigger, resulting in a much faster and more intense immune response when triggered a second time.   

Paradoxical   

Following this reasoning, anti-inflammatory effects and trained immunity are opposite effects. It therefore came as a big surprise when Rutger Röring, PhD student in Netea’s group, discovered that interleukin-4 (IL-4) both inhibited inflammation ánd activated trained immunity in primary human monocytes (white blood cells).