Development of salivary gland organoids derived from patient biopsies: a functional model of Sjögren’s disease

Salivary gland epithelial cells (SGECs) play a key role in Sjögren's disease (SjD) as an active contributor to the pathogenesis. Current models lack clear epithelial readouts. Our aim was to establish a more advanced model by developing salivary gland organoids (SGOs) from labial salivary gland biopsies (LSGBs) of SjD patients and sicca controls. We included SjD patients fulfilling the American College of Rheumatology/European League Against Rheumatism 2016 criteria and sicca controls. LSGBs were dissociated, encapsulated in extracellular matrix, and submerged in growth expansion medium for long-term culture. SGOs were primarily cultured in differentiation medium and then transferred to a low attachment plate to form differentiated SGOs (DIF-SGOs). We included 13 SjD and 15 controls. In both groups, SGOs were formed, demonstrating long-term culture viability and comparable self-renewal capacity (3.3 ± 1.7 months). DIF-SGOs comparably exhibited mature acinar (aquaporin 5, amylase), ductal (cytokeratins 5 and 7) and myoepithelial (α-smooth muscle actin) markers in both groups. DIF-SGOs were responsive to inflammation by expressing BAFF, CXCL10 and IL7 upon stimulation with poly(I:C) and interferon-α. DIF-SGOs also demonstrated a swelling response to cholinergic stimulation by pilocarpine. We observed significant differences between SjD- and control-derived SGOs. Notably, SjD-derived DIF-SGOs consistently maintained a persistent interferon signature throughout long-term culture. In addition, the swelling capacity was reduced in SjD-derived DIF-SGOs compared to control. However, treatment with tofacitinib enhanced the swelling ability, suggesting a potential effect on saliva production. We successfully developed SGOs from LSGBs of SjD patients, allowing long-term culture and faithfully recapitulating the disease phenotype. This model holds promise as a valuable tool for drug screening.