ABSTRACT
Candida is the most common human fungal pathogen and causes systemic infections that require neutrophils for effective host defense. Humans deficient in the C-type lectin pathway adaptor protein CARD9 develop spontaneous fungal disease that targets the central nervous system (CNS). However, how CARD9 promotes protective antifungal immunity in the CNS remains unclear. Here, we show that a patient with CARD9 deficiency had impaired neutrophil accumulation and induction of neutrophil-recruiting CXC chemokines in the cerebrospinal fluid despite uncontrolled CNS Candida infection. We phenocopied the human susceptibility in Card9-/- mice, which develop uncontrolled brain candidiasis with diminished neutrophil accumulation. The induction of neutrophil-recruiting CXC chemokines is significantly impaired in infected Card9-/- brains, from both myeloid and resident glial cellular sources, whereas cell-intrinsic neutrophil chemotaxis is Card9-independent. Taken together, our data highlight the critical role of CARD9-dependent neutrophil trafficking into the CNS and provide novel insight into the CNS fungal susceptibility of CARD9-deficient humans.
Subject(s)
CARD Signaling Adaptor Proteins/immunology , Candidiasis/immunology , Central Nervous System Infections/immunology , Immunologic Deficiency Syndromes/immunology , Neutrophil Infiltration/immunology , Animals , Blotting, Western , CARD Signaling Adaptor Proteins/deficiency , Female , Flow Cytometry , Humans , Immunologic Deficiency Syndromes/microbiology , Mice , Mice, KnockoutABSTRACT
Necrotizing fasciitis is a severe, rapidly progressive infection of the subcutaneous tissue that causes significant destruction. It is rarely encountered in the pediatric population. We describe the case of a 14-year-old boy who was diagnosed with Chromobacterium violaceum necrotizing fasciitis and subsequently found to have autosomal recessive chronic granulomatous disease.