Neutralization of IFNgamma defeats haemophagocytosis in LCMV-infected perforin- and Rab27a-deficient mice.

Hereditary haemophagocytic lymphohistiocytosis (HLH) is a fatal inflammatory disease and treatments currently may lead to serious side effects. There is a pressing need for effective, less toxic treatments for this disease. Previous reports have suggested that interferon gamma (IFNgamma) has a role in the pathogenesis of HLH.

Griscelli syndrome restricted to hypopigmentation results from a melanophilin defect (GS3) or a MYO5A F-exon deletion (GS1).

Griscelli syndrome (GS) is a rare autosomal recessive disorder that associates hypopigmentation, characterized by a silver-gray sheen of the hair and the presence of large clusters of pigment in the hair shaft, and the occurrence of either a primary neurological impairment or a severe immune disorder. Two different genetic forms, GS1 and GS2, respectively, account for the mutually exclusive neurological and immunological phenotypes. Mutations in the gene encoding the molecular motor protein Myosin Va (MyoVa) cause GS1 and the dilute mutant in mice, whereas mutations in the gene encoding the small GTPase Rab27a are responsible for GS2 and the ashen mouse model.