by Leigh MacMillan
Type 1 diabetes is an autoimmune disorder, in which activated immune system cells destroy the insulin-producing beta cells of the pancreas. Efforts to eliminate these activated immune cells have not produced positive long-term results.
Daniel Moore, MD, PhD, and colleagues tested an alternative approach: enhancing endogenous immune regulation with naturally occurring IgM-type antibodies. The investigators treated a mouse model of diabetes (NOD mice) with purified IgM isolated from a healthy strain of mice. The purified IgM reversed diabetes in NOD mice, eliminated the autoreactive B cells that promote beta cell attack and increased numbers of regulatory T cells.
In contrast, IgM from pre-diabetic NOD mice could not restore regulation, demonstrating that loss or dysfunction of protective IgM may contribute to diabetes pathogenesis. Importantly, IgM from healthy human donors protected against diabetes in NOD mice.
The findings, reported in the journal Diabetes, suggest that healthy IgM can be harnessed as a treatment for type 1 diabetes and potentially other autoimmune disorders.
This research was supported by the National Institutes of Health (grants DK107321 and AI119224), the Focus to Cure Diabetes Foundation, an American Diabetes Association Innovative Basic Science Award, a JDRF Career Development Award, and a Vanderbilt Digestive Disease Pilot grant.
