Innate immune adaptor MyD88 deficiency prevents skin inflammation in SHARPIN-deficient mice
Cell Death and Differentiation
Mice deficient in SHANK-associated RH domain-interacting protein (SHARPIN), a component of the linear ubiquitin chain assembly complex (LUBAC), develop a spontaneous inflammatory disorder with pathologic hallmarks similar to atopic dermatitis and psoriasis in humans. Previous studies identified the crucial role of components of the TNF and IL-1 signaling pathways in the progression of disease in SHARPIN-deficient mice. However, an innate immune adaptor or sensor that relates to the disease
... to the disease progression has remained unknown. In this study, we found that the genetic ablation of myeloid differentiation primary response 88 (MyD88) completely rescued skin inflammation in SHARPIN-deficient (Sharpin cpdm ) mice. Systemic inflammation and immune cell dysregulation were partially rescued. Fibroblasts derived from Sharpin cpdm Myd88 −⁄− mice failed to provide protection against TNF-induced cell death. Sharpin cpdm Myd88 −⁄− mice had reduced TNF production in their skin. Furthermore, depletion of the microbiota through the oral administration of antibiotics (ABX) partially rescued both the skin inflammation and systemic inflammation, demonstrating a role for the gut microbiota in SHARPIN-deficient mice. Our findings suggest a detrimental role for the innate immune adaptor MyD88 in instigating skin inflammation in Sharpin cpdm mice.