To accomplish our three aims, pOECs were infected with Ct for up to 72 hpi and at different time points, Ct-infected and control cells were harvested to (i) assess Ct development via flow cytometry, confocal and transmission electron microscopy (TEM), and qPCR, (ii) study the pOECs immune response to Ct infection via NanoString, and (iii) investigate the CLDN-4 mRNA, protein expression, and cellular location via NanoString, flow cytometry, and confocal microscopy, respectively. Here, CLDN4 is linked to infection.