Mycobacteria precipitate an SLE-like syndrome in diabetes-prone NOD mice.

Non-obese diabetic (NOD) mice spontaneously develop organ-specific autoimmunity and are widely used as a model for diabetes. Aged NOD mice also exhibit some features of non-organ-specific autoimmune rheumatic disease such as anti-nuclear antibodies and late-onset haemolytic anaemia. Here, we report that a single dose of 2.6 x 10(7) heat-killed bacillus Calmette-Guérin (BCG) i.v. in 8-week-old NOD mice prevented diabetes but precipitated a syndrome similar to systemic lupus erythematosus (SLE). Treated mice developed haemolytic anaemia, anti-DNA and anti-Sm anti-nuclear autoantibodies and an increased severity of sialadenitis. Perivascular lymphocytic infiltration in the kidneys and glomerular immune complex deposition were also found. The action of BCG appeared to be mediated by an adjuvant-like activity as treated mice showed a substantial increase in reticuloendothelial cell function and enhanced antigen presentation capacity.