Leonardo Elias Sternkopf (Munich / DE), Dr.rer.nat Fabien Ulrich Prodjinotho (Munich / DE), Prof. Dr. Kathrin Schumann (Munich / DE), Dr. Chummy Sikasunge (Lusaka / ZM), Dr. Julia Esser-von Bieren (Munich / DE), Prof. Dr. Clarissa Prazeres da costa (Munich / DE)
Abstract text
Introduction:
In human neurocysticercosis (NCC), caused by brain cysts of the pork tapeworm T. solium, and currently the most common cause of childhood epilepsy in many endemic areas worldwide, the immunopathogenesis and disease severity are determined by the viability of the cysts. Whereas viable cysts in the brain are associated with asymptomatic disease, decaying cysts, following treatment can cause severe inflammation, headaches and epileptic seizures. We recently showed that decaying cyst material causes brain microglia activation and peripheral immune cell apoptosis by yet unidentified mechanisms.
Objectives: Within this project, we aim to investigate the proapoptotic potential of decaying cyst (cyst vesicular fluid =CVF) on immune cell populations (T cells, monocytes, macrophages and microglia), the inflammatory mediators and pathways and associated CVF active molecules.
Materials and methods: Isolated human peripheral blood immune cells, monocytes as well as murine bone marrow derived macrophages and microglia were treated with CVF of cysts collected from naturally infected pigs. Cellular apoptosis and necrosis were analyzed using flow cytometry and culture supernatants were then screened for different inflammatory mediators (e.g. TNFα, ROS, Fas). Apoptosis pathways were identified following FLICA active caspases, selective ligand receptors blocking assays and CVF inducing molecules characterized the mean of mass spectrometry and biological function screening.
Results: CVF induced barely necrosis but rather apoptosis in a concentration and time dependent manners and targeting preferentially monocytes and CD3- cell populations more than CD3+ T cells. CVF molecules, potentially cathepsin B/D and calpains, promoted significant TNF-α from peripheral cells and TGF-ß from microglia as potential drivers of cellular apoptosis pathways and epileptic development.
Conclusion: With this work, we uncovered determinant mechanisms in cellular apoptosis underlying the immunopathogenesis of NCC that may offer an important therapeutic strategy in inflammatory epilepsy and NCC treated patients.