Spontaneous development of organ-specific autoimmune lesions in aged C57BL/6 mice.

We have shown that spontaneously occurring, organ-specific autoimmune lesions develop in aged C57BL/6 mice of both sexes, especially in 24-month-old senescent mice. The inflammatory lesions were found in the multiple organs such as salivary gland, kidney, pancreas, lung, and liver, associated with ageing process. Organ-specific autoimmune lesions first appeared in 6-month-old C57BL/6 mice, and were aggravated with advancing age. In contrast, significant inflammatory changes did not develop in the thyroid, stomach, testis, ovary, and prostate in aged C57BL/6 mice. The incidence and severity of organ-specific autoimmune lesions in this strain of non-autoimmune mice increase with advance of age. The most severely affected lesion was sialadenitis developed in the submandibular salivary gland of aged mice, and a significant difference between male and female mice was noted only in the salivary gland. The infiltrating cells within the lesions of multiple organs consisted mainly of Thy 1.2+ and L3T4+ cells. Autoantibodies were detected in the sera of the mice with each corresponding organ-specific autoimmune lesions.