The role of protein tyrosine phosphatase 1B ( PTP1B ) in generation of tolergenic dendritic cells (360G-Wellcome-211859_Z_18_Z)

In homeostatic conditions dendritic cells are tolerogenic (Tol DC) and therefore, supress immune reactions, making them a key element in the maintenance of peripheral tolerance. Upon challenge, these Tol DC convert into mature, pro-inflammatory DC capable of initiating immune responses, this conversion is key in the induction of uveitis. It has been demonstrated that Tol DCs exhibit hyperphosphorylation of STAT3, a component of JAK/STAT signalling pathway, which is critical in controlling DC function. Previously, the lab has demonstrated that protein tyrosine phosphatase 1B is a key regulator of DC function via a STAT3 dependent mechanism. This project will investigate the role of PTP1B in intrinsic STAT3 regulation in DC by utilising a novel DC specific PTP1B knock out model (Zbtb46-PTP1B). I hypothesis that deletion of PTP1B in DC will result in hyperphosphorylation of STAT3, and preservation of Tol DC phenotype upon inflammatory challenge. Firstly, maturation status will be assessed through surface and intracellular flow cytometry for key DC activation markers (CD40, CD68, CD40, MHC class II) and cytokines (IL-12 and IL-10). Secondly, through assessment of key signalling pathways (JAK-STAT, PI3K-AKT, ERK1/2) involved in DC function, through western blotting, to allow mechanistic insight into the signalling pathways controlling Tol DC phenotype.