gld/gld mice are unable to express a functional ligand for Fas

Mice homozygous for either the lpr or gld genes develop phenotypically identical autoimmune disorders. The gene responsible for the pathology in lpr/lpr mice encodes the Fas antigen, a protein associated with the induction of programmed cell death. To determine if the defect associated with gld represents a mutation in the ligand for Fas, we have assessed the ability of lymphoid cells from homozygous gld/gld mice to lyse target cells in a...