Preclinical Evaluation of Synthetic Biology-Driven Engineered Escherichia coli Nissle 1917 as a Living Therapeutic for Sustained L-DOPA Delivery.

Dopamine deficiency resulting from nigrostriatal dopaminergic neuronal damage manifests as extrapyramidal motor symptoms of Parkinson's disease (PD). Oral tablet dosing of levodopa, administered 3-4 times a day, remains the standard of care due to its tolerability and effectiveness; however, it is prone to deleterious side effects, including off-periods and levodopa-induced dyskinesia after long-term use. Herein, using synthetic biology approaches, we developed and systematically evaluated the feasibility of a probiotic-based live-biotherapeutic system to continuously deliver L-DOPA stably, thereby relieving motor symptoms. Our data demonstrate that our engineered plasmid-based L-DOPA-expressing Escherichia coli Nissle 1917 probiotic strain (EcN2LDOPA-P3) efficiently produced up to 12,000 ng/mL L-DOPA in vitro. In mouse model systems, EcN2LDOPA-P3 readily colonized for up to 48 h, achieved steady-state plasma L-DOPA concentrations, and increased brain L-DOPA and dopamine levels by 1- to 2-fold. Lastly, EcN2LDOPA-P3 significantly diminished motor and nonmotor behavioral deficits in a mouse model of PD compared to traditional chemical L-DOPA therapy. These findings support the therapeutic feasibility of a noninvasive, orally administered bioengineered bacterial therapy for the chronic delivery of L-DOPA, which may address limitations associated with current treatment alternatives.