@Article{biocell.2026.079046,
AUTHOR = {Laura Schaltz, Simon Lassnig, Karola Schlote, Christian Schwerk, Horst Schroten, Nicole de Buhr},
TITLE = {Characterization of Alive and Impaired NET-Releasing Neutrophils in A Model of the Blood-Cerebrospinal Fluid Barrier after <i>Streptococcus</i> <i>suis</i> Infection},
JOURNAL = {BIOCELL},
VOLUME = {},
YEAR = {},
NUMBER = {},
PAGES = {{pages}},
URL = {http://www.techscience.com/biocell/online/detail/26809},
ISSN = {1667-5746},
ABSTRACT = {<b>Objectives:</b> <i>Streptococcus suis</i> (<i>S. suis</i>) is a worldwide occurring pathogen in pigs and humans that can cross the blood-cerebrospinal fluid barrier (BCSFB) to cause meningitis, while host neutrophils counter infection through mechanisms including the release of neutrophil extracellular traps (NETs). NET-formation involves the release of nuclear DNA with antimicrobial components, which can bind and kill bacteria. We aimed to characterize the host-pathogen interaction between <i>S. suis</i> and neutrophils within the CSF compartment, focusing on NET-formation. <b>Methods:</b> A 3D cell culture model of the porcine BCSFB was used by cultivating a porcine choroid plexus epithelial cell line (PCP-R) on filter inserts. Following <i>S. suis</i> infection, porcine neutrophils were added to the basolateral side. The study specifically focused on the quantification of alive and impaired NET-releasing neutrophils. Transmigrated neutrophils in the CSF compartment were stained for NETs and with Live-or-Dye NucFix™ and analyzed by confocal microscopy to quantify NET release and cell viability. <b>Results:</b> In uninfected samples, most transmigrated neutrophils remained NET-negative (96.9% SD ± 1.9%). In contrast, 46.9% (SD ± 12.9%) of neutrophils infiltrating the <i>S. suis</i>-infected CSF compartment exhibited NET formation. Only a minor fraction of NET-releasing cells remained alive (9.8% SD ± 8.7%), whereas the majority became impaired (Live-or-Dye positive). This process correlated with increased <i>S. suis</i> colony-forming units in the CSF compartment. However, Live-or-Dye positive neutrophils retained the ability to produce reactive oxygen species (ROS) in response to <i>S. suis</i>, although ROS production decreased after 4 h. <b>Conclusion:</b> Using a novel staining approach to distinguish NET formation and cell viability, we demonstrated that <i>S. suis</i> infection predominantly induces NET release in the CSF compartment in an <i>in vitro</i> model of the BCSFB after four hours. The majority of these NET-releasing neutrophils are impaired. This likely leads to a loss of the defense mechanisms of the neutrophils.},
DOI = {10.32604/biocell.2026.079046}
}