Abstract
Over 20,000 New Zealanders are impacted by Inflammatory bowel diseases (IBD), which include Crohn’s disease (CD), ulcerative colitis and unclassified IBD. Crohn’s disease is a highly complex, multifactorial, idiopathic disease with multiple factors contributing to the pathogenesis, including host genetics, environmental factors, the microbiome, and the immune system. Anti-tumor necrosis factor (TNF) antibody (anti-TNF) is the main treatment for CD; however, a third of patients do not initially respond and a quarter of initial responders develop secondary non-response. Using two dimensional (2D) monolayers that are grown from three-dimensional (3D) intestinal organoids derived from non-IBD donors and CD patient colon biopsies, this research studied the effects of anti-TNF and probiotics in their ability to influence organoid integrity; differences in the epithelial integrity were compared via transepithelial electrical resistance (TEER). Changes in immune responses were also compared by measuring cytokine concentrations (via cytokine bead array) and by quantifying the frequency and phenotype of immune cells (via flow cytometry).
Firstly, to mimic a CD damaged intestine patient, matched peripheral blood mononuclear cells (PBMCs) were added to differentiated monolayers in the presence or absence of stimulating anti-CD3/CD28 beads. Stimulated PBMCs reduced the TEER and increased production of interferon (IFN)γ, TNF, interleukin (IL)-17 and IL-22. Flow cytometry analysis identified changes in multiple T cell populations. Secondly, anti-TNF was added to the monolayers 24 h after stimulated PBMCs. The addition of anti-TNF increased the TEER, to varying extents between donors. Anti-TNF caused a reduction in the total concentration of TNF; however, flow cytometry analysis identified no change in frequencies of CD4+TNF+ or CD8+TNF+ T cell populations. Lastly, to investigate alternative treatments, Vivomixx probiotics were added to damaged monolayers. Vivomixx did not increase TEER or reduce the amount of TNF cytokine concentration to the same extent as anti-TNF. When Vivomixx was added there were reductions in the frequencies of CD8+TNF+ and CD8+IFNγ+ populations in both non-IBD and CD monolayers.
Sample numbers were too low to conclude a definite result; however, this was a pilot study and these results demonstrated proof of principle and validated previous research in the lab. Overall, this study uses a unique individualized model that matches genetics, immune, environmental, and microbial factors to the original donor providing insightful results on alternative treatments for patients. These findings support work towards personalized medicine, improving patient outcomes by providing targeted treatments.