Systemic lupus erythematosus (SLE) develops when genetically susceptible individuals lose tolerance to autoantigens, likely as a result of an environmental insult. The list of identified genetic susceptibilities is expansive, however variants in the interferon regulatory factor 5 (IRF5) gene have consistently and convincingly been shown to be associated with an increased risk of developing SLE across all ethnic and racial groups examined. These genetic variants are hypothesized to produce a gain-of-function phenotype due to increased IRF5 mRNA and increased stability of the IRF5 protein; however, definitive functional studies examining these polymorphisms in primary human cells are not possible given the genetic variation from patient to patient. IRF5 is a transcription factor that is constitutively expressed in a number of immune cells including B cells and dendritic cells. IRF5 has cell type specific roles; in dendritic cells, it primarily controls a proinflammatory program which directs T cell polarization. Dysfunctional conventional dendritic cells (cDCs) have been implicated in the onset and development of SLE due to their high capacity to activate and interact with autoreactive lymphoid cells via a number of different pathways; the exact type of dysfunction and mechanisms underlying it are still debated. Study of primary cDCs either from SLE patients or healthy controls is complicated by the low frequency of cDCs in peripheral blood (<0.1%). To better evaluate the role IRF5 plays in cDC dysfunction in SLE, I developed a method for generating cDCs from induced pluripotent stem cells (iPSCs). The cDCs derived from this protocol are similar in many respects to primary human cDCs based on their gene expression profiles, cytokine production, and ability to act as antigen presenting cells to activate T cells. I also generated a library of iPSCs with and without the IRF5 risk haplotype to enable future studies to delineate the role of IRF5 polymorphisms in human cDCs. To facilitate these future studies, I also made an IRF5 deficient iPSC line which will be essential in discerning the role of IRF5 in cDC function. More broadly, we describe herein a platform to study gene function in an isogenic model of human conventional dendritic cells.
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/38586 |
| Date | 07 October 2019 |
| Creators | Baker, Margaret |
| Contributors | Rifkin, Ian, Mostoslavsky, Gustavo |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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