Project Summary/Abstract The goal of this project is to enhance our understanding of the IDG-eligible kinases DYRK1B, DYRK2, DYRK3 and DYRK4. Our preliminary data implicate at least one of these kinases in regulating differentiation of anti-inflammatory Tregs. Treg-modulating therapies are greatly needed, particularly in autoimmunity. We built a published pipeline to quantitate how genetic and chemical perturbations impact Treg differentiation, this showed that DYRK1A regulates Th17, but not Treg, differentiation. We now propose to use this pipeline to identify the Treg-regulating DYRK. This will illuminate a novel immune cellular phenotype for an IDG-eligible gene, develop validated tools to study IDG-DYRKs in primary cells, inform development of novel Treg-enhancing drugs and highlight patient subsets for precision therapy. Our long-term goal is to help develop better therapies, including inhibitors of specific DYRK family members, to treat autoimmunity. The overall objectives in this application are to (i) develop genetic tools to identify which DYRK family member regulates Treg differentiation, and (ii) interrogate functional and mechanistic features of DYRK-deficient Tregs. The central hypothesis is that an unidentified DYRK family member inhibits Treg differentiation. The rationale for this project is that identifying the Treg-regulating DYRK family member will offer a strong scientific framework to illuminate our understanding of understudied DYRK(s) as druggable regulators of autoimmunity pathobiology and establish a pipeline to illuminate other IDG-eligible genes. The central hypothesis will be tested in two specific aims: 1) Define how overexpression of IDG-DYRKs affects Treg differentiation, and 2) Define how IDG DYRK inhibitors and knockout of IDG-DYRKs affects Treg differentiation. The first aim will interrogate how overexpressing each DYRK family member in primary murine and human CD4+ T cells affects Treg differentiation. The second aim will mechanistically interrogate how knockout of each DYRK family member in primary murine and human CD4+ T cells affects Treg differentiation and function. These studies leverage our published experimental pipeline that quantitates how genetic or chemical perturbations impact T cell differentiation. Key innovative features of this proposal include studying the immune function of IDG-DYRKs and the use of primary immune cells. The proposed research is significant because it is expected to (i) reveal a new cellular phenotype for an understudied gene of interest to IDG, (ii) identify a novel druggable regulator of autoimmune pathobiology, thus directing future mechanistic and therapeutic studies, (iii) develop characterized tools to manipulate understudied DYRKs in other primary cells and biologic contexts and (iv) establish a scalable pipeline that can be used to rapidly interrogate all genes of interest to IDG for effects on differentiation into Tregs as well as other lineages including Th17, Th1 and Th2. Ultimately, this has the potential to broadly illuminate immune function of IDG genes and advance precision therapy of autoimmunity for people in the general population.

Project Narrative The proposed research is relevant to public health because it seeks to identify the specific DYRK family member that regulates the differentiation of Tregs, which are key regulators of inflammation. This knowledge would help develop novel therapeutics for autoimmunity and inflammatory disorders, as well as establish the foundation to identify the patients these therapies would most benefit. Thus, the proposed research is relevant to the part of NIH's mission pertaining to reducing illness and disability.