While tumors upregulate immune checkpoint molecules such as PD-L1 on their surface to inhibit T cell activity, the generalized immune-inhibitory tumor microenvironment can also polarize T cells to a suppressive phenotype known as regulatory T cells, or Tregs. Tregs are CD4+ T cells characterized by the secretion of the regulatory cytokine IL-10, which is inhibitory to both macrophages and T cells, and can to suppress the activity of tumor-directed T cells.
We have developed an assay that robustly generates Tregs and measures their ability to suppress T cell proliferation. Test your compound’s ability to modulate Treg polarization or to reverse suppression of T cell proliferation, thereby boosting anti-tumor T cell activity.
What can we observe?
CD4+ T cells can be efficiently polarized to Tregs using a cytokine cocktail containing IL-2 and TGF-β1. Efficient polarization to the Treg phenotype is measured by the upregulation of the transcription factor Foxp3 using flow cytometry (see diagram).
We have demonstrated that coculture of naive CD8+ T cells (effector T cells, or Teff) with polarized Tregs dose-dependently inhibits CD8+ T cell proliferation compared to incubation of CD8+ T cells alone. Results are expressed as % suppression.
There is a baseline lack of proliferation in CD8+ T cells alone (blue line), with a dose-dependent increase in suppression following the addition of Tregs (orange line), leading to 90% suppression of CD8+ proliferation at the highest dose of Tregs.
We can assess your compound for its ability to relieve Treg suppression on T cells, as well as its ability to prevent T cell polarization to the Treg state.
For more information on this service or to discuss your requirements with our team.