Systemic elimination of macrophages using liposomes does not prevent the induction of type I diabetes

Silica treatment of experimental animals leads to a prevention of genetically determined or experimentally induced type I autoimmune diabetes. Since silica is toxic for macrophages an important involvement of these cells in the onset of the disease was concluded. Here we show that in vivo elimination of macrophages by liposome treatment does not lead to prevention of streptozotocin-induced diabetes. The results indicate that the presence of mature macrophages is not an important requisite for diabetes induction and that the effects of silica treatment must be attributed to activation of macrophages leading to disturbed cytokine levels, or to effects on other cell types.