Dr. Alexandra Ehrens Awarded the Paul Ehrlich Society for Chemotherapy Doctoral Prize

For her outstanding doctoral work, Dr. Alexandra Ehrens was awarded the Paul Ehrlich Society for Chemotherapy doctoral prize, the PEG-Pro­mo­ti­ons­preis. The dissertation titled "Microfilariae trigger eosinophil extracellular DNA traps in a Dectin-1-dependent manner" addresses two important issues in the fight against worm infections, first the role of the immune system and secondly identification of new drug.

The first part looks into the role eosinophil extracellular DNA traps play in response to different larval stages of the rodent filaria Litomosoides sigmodontis. Eosinophils make an important contribution in the control of adult worms and their progeny, microfilariae (MF). Results demonstrate that murine eosinophil granulocytes are not only capable of producing extracellular DNA traps in response to microfilariae and infectious L3 larvae, but that these also help to trap the microfilariae in a DNA network-dependent mechanism and accelerate their elimination. The results also demonstrate a dectin-1-dependent ETosis leading to nuclear and mitochondrial DNA shedding. Furthermore, Dr. Ehrens showed that eosinophil ETosis is a conserved mechanism among different species, as not only murine eosinophils but also human eosinophils secrete extracellular DNA in response to microfilariae of the rodent filariae L. sigmodontis and the canine heartworm Dirofilaria immitis. These findings suggest that eosinophil ETosis is an important mechanism in the control of microfilariae and thus make an important contribution in the knowledge of protective immune responses against filariae.

In the second part of her dissertation, Dr. Ehrens contributed decisively to the identification of new macrofilaricidal compounds that could reduce the necessary treatment time to 7-14 days and are urgently needed for the elimination of human filariasis.