Transcriptomic profiling of human SHARPIN deficiency

The linear ubiquitin assembly complex (LUBAC) consists of HOIP, HOIL-1 and SHARPIN, and is essential for proper immune responses. Patients with HOIP and HOIL-1 deficiencies present with severe immunodeficiency, autoinflammation and glycogen storage. In mice, the loss of Sharpin leads to severe dermatitis due to excessive cell death in keratinocytes. Here we report two patients with SHARPIN deficiency manifesting autoinflammatory symptoms but unexpectedly, no dermatologic manifestations. Patient fibroblasts and B cells showed attenuated canonical NF-κB response and propensity to cell death mediated by TNF superfamily members. Both SHARPIN- and HOIP-deficient patients showed substantial reduction of secondary lymphoid germinal center B cell development. Treatment of one SHARPIN-deficient patient with anti-TNF therapies led to complete clinical and transcriptomic resolution of autoinflammation. These findings underscore the critical role of LUBAC as a gatekeeper for cell death-mediated immune dysregulation in humans.