Three-dimensional models of human intestinal epithelium mimic the differentiated form and function of parental tissues often not exhibited by two-dimensional monolayers and respond to Salmonella in key ways that reflect in vivo infections. To further enhance the physiological relevance of three-dimensional models to more closely approximate in vivo intestinal microenvironments encountered by Salmonella, we developed and validated a novel three-dimensional co-culture infection model of colonic epithelial cells and macrophages using the NASA Rotating Wall Vessel bioreactor. First, U937 cells were activated upon collagen-coated scaffolds. HT-29 epithelial cells were then added and the three-dimensional model was cultured in the bioreactor until optimal differentiation was reached, as assessed by immunohistochemical profiling and bead uptake assays. The new co-culture model exhibited in vivo-like structural and phenotypic characteristics, including three-dimensional architecture, apical-basolateral polarity, well-formed tight/adherens junctions, mucin, multiple epithelial cell types, and functional macrophages. Phagocytic activity of macrophages was confirmed by uptake of inert, bacteria-sized beads. Contribution of macrophages to infection was assessed by colonization studies of Salmonella pathovars with different host adaptations and disease phenotypes (Typhimurium ST19 strain SL1344 and ST313 strain D23580; Typhi Ty2). In addition, Salmonella were cultured aerobically or microaerobically, recapitulating environments encountered prior to and during intestinal infection, respectively. All Salmonella strains exhibited decreased colonization in co-culture (HT-29-U937) relative to epithelial (HT-29) models, indicating antimicrobial function of macrophages. Interestingly, D23580 exhibited enhanced replication/survival in both models following invasion. Pathovar-specific differences in colonization and intracellular co-localization patterns were observed. These findings emphasize the power of incorporating a series of related three-dimensional models within a study to identify microenvironmental factors important for regulating infection.
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- Three-Dimensional Organotypic Co-Culture Model of Intestinal Epithelial Cells and Macrophages to Study Salmonella Enterica Colonization Patterns
- Barrila, Jennifer (Author)
- Yang, Jiseon (Author)
- Crabbe, Aurelie (Author)
- Sarker, Shameema (Author)
- Liu, Yulong (Author)
- Ott, C. Mark (Author)
- Nelman-Gonzalez, Mayra A. (Author)
- Clemett, Simon J. (Author)
- Nydam, Seth (Author)
- Forsyth, Rebecca (Author)
- Davis, Richard (Author)
- Crucian, Brian E. (Author)
- Quiriarte, Heather (Author)
- Roland, Kenneth (Author)
- Brenneman, Karen (Author)
- Sams, Clarence (Author)
- Loscher, Christine (Author)
- Nickerson, Cheryl (Author)
- ASU Biodesign Center Immunotherapy, Vaccines and Virotherapy (Contributor)
- Biodesign Institute (Contributor)
- Digital object identifier: 10.1038/s41526-017-0011-2
- Identifier TypeInternational standard serial numberIdentifier Value2373-8065
- The final version of this article, as published in Npj Microgravity, can be viewed online at: http://www.nature.com/articles/s41526-017-0011-2
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Barrila, J., Yang, J., Crabbé, A., Sarker, S. F., Liu, Y., Ott, C. M., . . . Nickerson, C. A. (2017). Three-dimensional organotypic co-culture model of intestinal epithelial cells and macrophages to study Salmonella enterica colonization patterns. Npj Microgravity, 3(1). doi:10.1038/s41526-017-0011-2