Cristina Padilla, MD NIAMS Diversity Supplement 2024-2026 The Molecular Basis of Altered Natural Kill Cells in Systemic Sclerosis-associated Interstitial Lung Disease Project Summary An activated, cytotoxic natural killer (NK) cell population was identified in scleroderma-associated interstitial lung disease (SSc-ILD) that showed upregulation in several genes, including Granzyme B, Amphiregulin, and Interferon-gamma. Because the genes are suspected to play a critical role in the pathogenic effects in the lungs, this project will use single cell technologies, including single cell ATAC sequencing (scATAC-seq) and Multiome-seq (combined single nuclear RNA-seq and snATAC-seq), to understand how these genes are regulated. By assessing the state of open chromatin across the genome using computational analysis, transcription factors (TF) can be predicted that are regulating this process. Experiments will be utilized to better understand the pathways that cause NK cell activation in SSc-ILD by comparing TF regulating SSc-ILD NK cells from lung with TF activated by cytokine simulation in vitro of NK cells purified from blood and healthy lungs. We hypothesize that open chromatin in NK cells will implicate key transcription factors (TFs) that regulate NK cell activation in SSc-ILD lungs, and that alteration of these TFs drive expression of AREG, IFNG and GZMB, as well as other key genes in their aberrant pathway of differentiation.

Project Narrative NIAMS Diversity Supplement 2024-2026 The Molecular Basis of Altered Natural Kill Cells in Systemic Sclerosis-associated Interstitial Lung Disease Scleroderma is a devastating autoimmune disease with interstitial lung disease, a leading cause of death in patients and for which limited, effective therapies are available. This project will study natural killer (NK) cells, an immune cell that may be contributing to scleroderma associated- interstitial lung disease (SSc-ILD). By studying how genes of interest from NK cells turn on in scleroderma lung tissue compared to healthy control lung, we will gain further understanding about how NK cells cause lung damage and scarring in scleroderma as well as discover potential molecules to target for new treatment in SSc-ILD.