David versus Goliath

Of Filariae and Eosinophil ETosis

Filarial infections can cause deblitating human diseases like elephantiasis and river blindness.
Infectious L3 larvae are transmitted by a vector and develop into adult worms, which release microfilariae, the progeny of the filariae. During a primary infection, neutrophils are the first line of defense against L3 larvae, while eosinophil numbers rise during the course of infection and play an important role against adult worms and micro filariae.

Eosinophils are major players in the defense of several pathogens but in particular they are important in the fight against filariae. The release of their cytotoxic granules mediates the attack of the pathogens. In addition, eosinophils are able to release granules together with DNA traps during ETosis (Extracellular DNA trap cell death). This sticky DNA mediates
the encapturing of pathogens and promotes their killing. While naive eosinophils are not able to recognize L3 larvae during the first worm encounter, eosinophils do recognize the worms through specific antibodies during a second infection.

Author: Alexandra Ehrens


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