W197 - Single-cell Multiomic Evaluation of Mechanisms Driving Dysregulation of the Adaptive Immune System in Preclinical Autoimmune Disease State

Aleksandra Bylinska – Oklahoma Medical Research Foundation; Miles Smith – Oklahoma Medical Research Foundation; Rufei Lu – Oklahoma Medical Research Foundation; Ben Jones – Oklahoma Medical Research Foundation; Carla Guthridge – Oklahoma Medical Research Foundation; Caleb Marlin – Oklahoma Medical Research Foundation; Christian Wright – Oklahoma Medical Research Foundation; Susan Macwana – Oklahoma Medical Research Foundation; Wade DeJager – Oklahoma Medical Research Foundation; Marci Beel – Oklahoma Medical Research Foundation; Chris Lessard – Oklahoma Medical Research Foundation; Cristina Arriens – Oklahoma Medical Research Foundation; Joan Merrill – Oklahoma Medical Research Foundation; Judith James – Oklahoma Medical Research Foundation; Joel Guthridge – Oklahoma Medical Research Foundation

Abstract Text: Background. A loss of tolerance to self-antigens leads to increased levels of autoantibodies against nuclear components (ANA) prior to clinical disease onset. Only 4-8% develop autoimmune disease. Patients with incomplete lupus erythematosus (ILE) exhibit some clinical symptoms with most never progressing to Systemic Lupus Erythematosus (SLE). This study investigates whether alterations in lymphocyte populations and activation of cellular processes affect preclinical autoimmunity development.
Methods. PBMCs from 64 subjects, divided evenly among disease groups: healthy (ANA-), healthy with autoantibodies (ANA+), ILE, SLE, were used for 5’scRNA-seq/137-plex Total-seq, BCR/TCR repertoire to identify disease-associated clusters, differential gene signatures, dysregulated pathways. Serum soluble biomarkers levels were obtained via Olink Proximity Extension Assay (Explore HT).
Results. We obtained profiles for ~650,000 cells across all PBMCs. Analysis of differentially expressed genes in T, B cells revealed importance of metabolic processes - oxidative phosphorylation, autophagy, mitochondrial dysfunction and dysregulation of MAPK signaling with disease progression. Cytokine storm signaling was downregulated in T cells of ANA+. These findings were confirmed by protein. We also identified a cytotoxic CD4+ T cell population in individuals with higher levels of IFN genes and increased antiviral response. VDJ analysis indicates cytotoxic T cells have largest fraction of expanded clonotypes, associated with higher expression of TXNIP, TMSB4X, HLA, GZMB and shared among ANA+ and ILE individuals.
Conclusions. These findings suggest that alterations in the adaptive immune system, in particular dysregulation of signaling in T and B cell activation related to changes in metabolic and apoptotic pathways play important role in preclinical autoimmunity trajectory.