Immune complex stimulation of human monocytes

Systemic sclerosis (SSc) is an autoimmune disease and several distinct autoantibodies have been described in SSc patients, many correlating with specific clinical presentation. Numerous studies have documented the presence of immune complexes (IC) in sera, lungs and BAL of SSc patients, potentially implicating them in the pathogenesis. Monocyte/macrophage activation also have been observed in fibrotic SSc skin and lung tissue. While the upstream activators remain unknown, it is plausible that IC are amongst the key triggers in activating monocytes and sustaining the chronic inflammation and fibrosis in SSc tissue. To test this hypothesis and find the specific downstream genes regulated by IC, we compare the gene expressions of the monocytes stimulated by control medium, LPS and IC using RNA seq. OPN was one of these IC regulated genes. Our paper further suggested that circulating OPN levels serve as a systemic proxy for IC driven profibrotic macrophage activity, highlighting its potential as a promising biomarker in SSc-ILD. CD14+ monocytes were purified from the PBMCs of 5 donors. Monocytes were then stimulated with either plate bound immune complex or LPS for 18 h, or left unstimulated. Groups: 1) Unstimulated (5 samples), 1) LPS stimulated DMSO (5 samples), 3) IC stimulated DMSO (5 samples). **Raw data not provided for patient privacy reasons**