In systemic lupus erythematosus (lupus), environmental effects acting within a permissive genetic background lead to autoimmune dysregulation. Dysfunction of CD4+ T cells contributes to pathology by providing help to autoreactive B and T cells, and CD4+ T cell dysfunction coincides with altered DNA methylation and histone modifications of select gene loci. However, chromatin accessibility states of distinct T cell subsets and mechanisms driving heterogeneous chromatin states across patients remain poorly understood. We defined the transcriptome and epigenome of multiple CD4+ T cell populations from patients with lupus and healthy individuals. Most patients with lupus, regardless of disease activity, had enhanced chromatin accessibility bearing hallmarks of inflammatory cytokine signals. Single-cell approaches revealed that chromatin changes extended to naive CD4+ T cells, uniformly affecting naive subpopulations. Transcriptional data and cellular and protein analyses suggested that the TNF family members, TNF-α, LIGHT, and TWEAK, were linked to observed molecular changes and the altered lupus chromatin state. However, we identified a patient subgroup prescribed angiotensin receptor blockers (ARBs), which lacked TNF-linked lupus chromatin accessibility features. These data raise questions about the role of lupus-associated chromatin changes in naive CD4+ T cell activation and differentiation and implicate ARBs in the regulation of disease-driven epigenetic states.
Andrew P. Hart, Jonathan J. Kotzin, Steffan W. Schulz, Jonathan S. Dunham, Alison L. Keenan, Joshua F. Baker, Andrew D. Wells, Daniel P. Beiting, Terri M. Laufer