1. Systemic exposure to irradiated apoptotic cells induces autoantibody production. Normal mice injected with 10^7 syngenic, apoptotic thymocytes developed transient and low titer of anti-nuclear antibody, anti-cardiolipin, and anti-ssDNA antibody. All immunized mice had IgG deposition in the glomeruli several months after immunization. IgG-deposition was not found in the glomeruli of non-immunized or syngenic splenocyte-immunized controls.