Human OTULIN haploinsufficiency impairs cell-intrinsic immunity to staphylococcal alpha-toxin

The molecular basis of interindividual clinical variability upon infection with Staphylococcus aureus is unclear. We describe patients with haploinsufficiency for the linear deubiquitinase OTULIN, encoded on chromosome 5p. The patients suffer from episodes of life-threatening necrosis, typically triggered by S. aureus infections. The disorder is phenocopied in patients with the 5p- (Cri-du-Chat) chromosomal deletion syndrome. OTULIN haploinsufficiency causes an accumulation of linear ubiquitin in dermal fibroblasts, but TNF-receptor NF-kB-signaling remains intact. Blood leukocyte subsets are unaffected. The OTULIN-dependent accumulation of caveolin-1 in dermal fibroblasts - but not leukocytes - facilitates the cytotoxic damage inflicted by the staphylococcal virulence factor alpha-toxin. Naturally elicited antibodies to alpha-toxin contribute to incomplete clinical penetrance. By disrupting cell-intrinsic immunity to alpha-toxin in non-leukocytic cells, human OTULIN haploinsufficiency underlies life-threatening staphylococcal disease.