Development of an in vitro model for studying extrusions in Chlamydia trachomatis infection

<p class="p1">Chlamydia trachomatis is released from host cells through cell lysis or extrusion, the latter of which may confer advantages such as reduced host inflammation and preservation of epithelial integrity. Despite its potential significance, extrusion remains poorly understood, and current models do not utilize clinically relevant cell lines. To address this gap, we evaluated a human oviduct epithelial (OE) cell line as an in vitro model for C. trachomatis extrusion. Using fluorescent and light microscopy, we characterized fluorescently tagged C. trachomatis strains during infection and extrusion from OE cells. Flow cytometry was used to quantify infections and extrusion events. Extruded C. trachomatis was successfully visualized by fluorescent microscopy, demonstrating the feasibility of extrusion studies in OE cells. However, flow cytometry was unable to reliably quantify extrusion events, highlighting the need for optimized protocols. Collectively, these findings establish a foundation for future studies using OE cells to explore extrusion mechanisms and their implications in C. trachomatis pathogenesis in humans.