Study Reveals T Cells' Aggression Against Parkinson's Effects

The immune system may not be as detrimental in the fight against neurological disease than previously thought.

A study from the National Institute of Neurological Disorders and Stroke (NINDS) — as part of the National Institutes of Health (NIH) — found results that suggest T cells may play a role in fighting Parkinson’s disease (PD).

The team of researchers — led by Columbia University professor of neurology David Sulzer, PhD, and professor of infectious disease at the La Jolla Institute for Allergy and Immunology, Alessandro Sette, Dr. Bio.Sci. — extracted immune cells from the blood samples of 67 PD patients and 36 healthy controls.

The immune cell extractions were mixed with portions of the alpha-synuclein protein — an accumulated substance found in the brains of PD patients that can cause cell death. T cells from PD patients responded in a more significant manner to the protein than the T cells from healthy samples.

A region of the alpha-synuclein protein that usually contains mutations linked to PD drew more reaction from the added T cells, according to researchers — as did a region of the protein that undergoes chemical changes which can lead to protein accumulation in the brain.

In the researcher’s 4 identified variants associated with T cell reactivity to alpha-synuclein, more than 50% of PD patients carried at least one of the variants. Just 20% of control patients carried at least of these variants. The findings indicate PD causes the immune system to incorrectly attack the body’s own cells, much like an autoimmune disease.

Proteins throughout the body undergo molecular changes as people age, Sulker explained.

“If they become unrecognizable, the immune system may start going after them, thinking they may be dangerous invaders,” Sulzer said.

Sette noted these findings indicate a “potential biomarker for PD” that could eventually help in disease diagnosis or treatment evaluation.

Codrin Lungu, MD, program director of the NINDS division of clinical research, said that although the study’s overall results were already known “to some extent” in neurological research, it highlights very specific issues in the duality of Parkinson’s disease — its immune and inflammatory components.

“It certainly finds a couple of important steps for moving forward,” Lungu said.

The research particularly feeds to the ongoing effort by neurologists to find a disease-modifying therapy (DMT) for PD, of which there are still missing gaps of information. Lungu said it is still not entirely clear what causes, or even what the body’s reaction to the disease’s cause is.

Parkinson’s disease is now officially a 200-year-old known disease, Lungu noted. As much as is known on its effects of the entire body, it’s still a complicated condition that will take a multimodal approach to adequately treat.

“Little by little we’re finding targets for disease modification,” Lungu said. “But the bottom line is we still do not have a disease-modifying therapy.”

The study, “T cells from patients with Parkinson’s disease recognize α-synuclein peptides,” was published online in the journal Nature last month.

A press release regarding the study was made available.

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