New DNA vaccine lowers levels of immune cells responsible for Type 1 diabetes

Washington: A clinical trial of a vaccine, which was designed by researchers to fight type-1 diabetes, has delivered promising results.

First, levels of a blood-borne proxy of insulin production were maintained - and in some cases increased - over the course of the 12-week dosing regimen, which indicated that those getting the vaccine may have suffered less ongoing destruction of beta cells, which produce and secrete the peptide hormone insulin after a meal, than those given placebo injections.

Second, blood levels of a specific group of immune cells that inappropriately home in on and destroy a protein found only on beta cells appear to have been selectively depleted in patients receiving the vaccine.

No adverse effects, serious or otherwise, that could be attributed to the vaccine were observed.

Lawrence Steinman, MD, professor of pediatrics and of neurology and neurological sciences at Stanford, said that they are excited by the results, which suggest that the immunologist`s dream of shutting down just a single subset of dysfunctional immune cells without wrecking the whole immune system may be attainable.

He said that this vaccine is a new concept, which is shutting off a specific immune response, rather than turning on specific immune responses as conventional vaccines for, say, influenza or polio aim to do.

To date, no DNA vaccine has ever been approved for human use, and any likely application is several years off.

According to the study, the vaccine`s observed beneficial effects began to drop off a few weeks after the 12-week vaccine-dosing schedule was discontinued.

The study has been published in Science Translational Medicine.