The researchers were looking to specifically stop the autoimmune response that causes type 1 diabetes without damaging the immune cells that provide protection against infections. Type 1 diabetes is caused when certain white blood cells – called T cells – mistakenly attack and destroy the insulin-producing beta cells in the pancreas. "Essentially there is an internal tug-of-war between aggressive T-cells that want to cause the disease and weaker T cells that want to stop it from occurring," said lead researcher Pere Santamaria.
The researchers developed a vaccine comprised of nanoparticles. These nanoparticles are coated with protein fragments – peptides – specific to type 1 diabetes that are bound to molecules that play a critical role in presenting peptides to T cells.
The nanoparticle vaccine worked by expanding the number of peptide-specific regulatory T cells that suppressed the aggressive immune attack that destroys beta cells. The expanded peptide-specific regulatory cells shut down the autoimmune attack by preventing aggressive autoimmune cells from being stimulated by either the peptide contained in the vaccine or by any other type 1 diabetes autoantigen presented simultaneously on the same antigen presenting cell.
The research also provided an insight into the ability to translate these findings in mice into therapeutics for people with diabetes: nanoparticles that contained human diabetes-related molecules were able to restore normal blood sugar levels in a humanized mouse model of diabetes.
Only the immune cells specifically focused on aggressively destroying beta cells (or, alternatively, regulating these cells) responded to the antigen-specific nanoparticle vaccine. That means the treatment did not compromise the rest of the immune system – a key consideration for the treatment to be safe and effective in an otherwise healthy person with type 1 diabetes.
MEDICA.de; Source: Juvenile Diabetes Research Foundation International