Establishment and characterization of primary gallbladder epithelial cell cultures in the prairie dog

Background. The prairie dog has become the established animal gallstone model. This species has a unique propensity to form cholesterol gallstones in response to dietary manipulations. The development of a reliable gallbladder cell culture technique is critical for understanding pathogenic mechanisms of gallstone formation. Materials and methods. Prairie dogs underwent laparotomy and cholecystectomy, followed by initiation of cell cultures. [³H]Thymidine incorporation was used to assess cell growth, and cell lines were assessed using routine histochemical and immunohistochemical staining. Results. Cell yields from prairie dog gallbladders were 4-8 x 10⁶ viable cells per animal with viability ranging from 80 to 95%. When plated at 5 x 10⁵ cells/cm², cell clusters, visible within 24 h, coalesced into confluent monolayers within 3-5 days. Cultures remained viable for 6-8 weeks and could be passed for three to four subcultures. Immunohistochemical staining demonstrated a high degree of epithelial purity with immunopositivity for AE1/AE3, and cytokeratin, with no vimentin positivity (mesenchymal antigen). Intracytoplasmic vacuoles demonstrated positive staining for Alcian blue, periodic acid-Schiff, and mucicarmine and an antigallbladder mucin antibody confirmed the presence of the glycoprotein mucin. Conclusions. This study demonstrates a reliable method for initiation and maintenance of prairie dog gallbladder epithelial cell cultures with a high degree of purity. This technique should allow further studies into the pathogenesis of cholesterol gallstones in this model.