Induction of NETosis in ovine colostral PMN upon exposure to Neospora caninum tachyzoites

Lukas Demattio; Ivan Conejeros; Daniela Grob; Ulrich Gärtner; Anja Taubert; Carlos Hermosilla; Axel Wehrend

doi:10.3389/fvets.2023.1176144

Induction of NETosis in ovine colostral PMN upon exposure to Neospora caninum tachyzoites

Front Vet Sci. 2023 Jun 19:10:1176144. doi: 10.3389/fvets.2023.1176144. eCollection 2023.

Authors

Lukas Demattio¹, Ivan Conejeros², Daniela Grob², Ulrich Gärtner³, Anja Taubert², Carlos Hermosilla², Axel Wehrend¹

Affiliations

¹ Clinic for Obstetrics, Gynaecology and Andrology of Small and Large Animals, Justus Liebig University Giessen, Giessen, Germany.
² Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany.
³ Institute of Anatomy and Cell Biology, Justus Liebig University Giessen, Giessen, Germany.

Abstract

Colostrum is one of the most important factors influencing the health and development of mammalian neonates. It is well-established that leukocytes, including polymorphonuclear neutrophils (PMN), migrate from the mother to the infant via colostrum uptake. In this study, for the first time, we studied the ability of ovine colostral-derived PMN to extrude neutrophil extracellular traps (NETs) against the abortive apicomplexan parasite Neospora caninum. Although this cell population plays a significant role in the transmission of maternal innate immunity to neonates, little is known about colostral PMN activities in sheep. However, this cell population is a significant source of the transfer of maternal immunity to the neonate. Colostral PMN continues to exert immunological effects even after transitioning into the colostrum. The present study aimed to investigate the extrusion of NETs by ovine colostral PMN exposed to the apicomplexan parasite, N. caninum, which is known to cause devastating reproductive disorders in cattle, small ruminants, wildlife animals, and dogs. The present study is the first to demonstrate that ovine colostral PMN can produce NETs after stimulation with vital N. caninum tachyzoites. Ovine colostrum-derived NETs were detected by chromatin staining and antibody-based immunofluorescence staining of NET-specific structures, including neutrophil elastase (NE) and global histones (H1, H2A/H2B, H3, H4), as well as scanning electron microscopy (SEM) analysis.

Keywords: NETosis; Neospora caninum; colostrum; neutrophil extracellular traps; ovine PMN.

Grants and funding

The Bruns Foundation supplemented the first author (LD) by a scholarship. This work was partially funded by a German BMBF (Bundesministerium für Bildung und Forschung)-awarded DLR project (“CryptoNETs”; project number 01DG20023) to CH.