Irradiation of NZBWF1 mice is an effective therapy for SLE-like morbidity.

CD180 molecule expressed on mature B cells is a key regulator of cell proliferation and death, showing a protective effect against radiation-induced apoptosis in vitro. In SLE patients, the number of CD180-negative cells increased in peripheral blood, and appeared to be associated with the activity of SLE. Furthermore, production of autoantibodies was found by CD180-negative cells from SLE patients. We previously showed that CD180-negative cells were more radiosensitive than CD180-positive cells in vivo. In SLE-model NZBWF1 mouse, we also reported the increase in number of CD180-negative B cells in parallel with development of SLE morbidity, the production of autoantibodies by CD180-negative cells, and pathogenesis of lupus-like nephritis caused by CD180-negative cells. In the present study, we attempted to examine the effects of irradiation on CD180-negative cells in NZBWF1 mice. After the onset of symptoms, mice were paired according to their conditions. In each pair, one was irradiated with 4 Gy, and the other was sham-irradiated. Compared to the sham-irradiated mice, the mean number of CD180-negative cells was significantly decreased, the mean life span was markedly extended, and the nephritis was suppressed in irradiated mice. The results suggest that radiation could effectively eliminate CD180-negative cells, leading to reduction of autoantibody production, and consequently relieve the SLE symptoms in the mouse. These findings suggest that the radiotherapy of autoimmune diseases associated with the expression of CD180-negative cells is a novel candidate for practical application.国際免疫学会2016 (16th international Congress of Immunology