IL-10RA governor the expression of IDO in the instruction of lymphocyte immunity
Menée à l'aide de cellules souches mésenchymateuses de moelle osseuse humaine et d'organoïdes d'adénocarcinomes canalaires du pancréas issus de patients, cette étude met en évidence un mécanisme par lequel la sous-unité alpha du récepteur de l'interleukine IL-10 favorise la suppression des lymphocytes T en augmentant l'expression de l'indoléamine 2, 3-dioxygénase
Background : Indoleamine 2,3-dioxygenase (IDO) impairs anti-pathogen and anti-tumour immunity. Mesenchymal stem cells (MSCs) modulate immunity via IDO but also suppress IFN-
γ. While MSC IDO induction by IFN-γ is established, other drivers in this immunosuppressive setting remain unknown.
Methods
:
Human bone marrow mesenchymal stem cells (MSCs) with IDO or IL-10RA knockdown were co-cultured with healthy donor T cells to assess immunosuppression. PDAC organoid anticancer activity was also tested in these co-cultures.
Results
:
Co-culturing MSCs with T cells in an IL-10RA-enriched environment enhances IDO expression, resulting in T cell suppression. Moreover, IL-10RA-positive MSCs collected from co-cultures with IL-10 supplementation show increased IDO expression. Conversely, MSCs with IL-10RA knockdown exhibit a significant reduction in IDO RNA and protein expression, as well as STAT3 phosphorylation status, which is a known upstream signalling pathway in IDO gene regulation, in T cell co-cultures. Down-regulation of IL-10RA also inhibits IDO activity in MSCs, resulting in reduced T cell suppression, and enabling the co-cultured T cells to kill PDAC organoids.
Conclusion
:
Our research reveals IL-10RA as a pharmacological target in stromal cells for enhancing T cell-mediated PDAC eradication by downregulating IDO via blocked IL-10/IL-10RA signalling in MSCs. This advances IL-10RA interference in the tumour microenvironment (TME) to restore T cell cytotoxicity against cancers.
British Journal of Cancer , article en libre accès, 2024