(251e) Targeting IL-10 to Atherosclerotic Plaques Reduces Vascular Inflammation

Introduction: Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of cholesterol on vascular walls and subsequent formation of plaques. Current preventative measures such as statins and dietary changes focus on reducing circulating “bad cholesterol” or low-density lipoprotein (LDL) and often lead to surgical interventions associated with high cost and morbidity. As an orthogonal approach, modulating the immune response to LDL can limit plaque formation. For example, overexpression of the anti-inflammatory cytokine IL-10 results in reduced lesion sizes. However, IL-10 has a poor pharmacokinetic profile and potential to cause systemic immunosuppression, which limit its therapeutic potential.

Methods: To overcome these challenges, we engineered constructs that target atherosclerotic plaques by fusing IL-10 to an antibody fragment (Fab) that binds LDL. We expressed six different Fab-IL-10 constructs: five with Fabs specific for LDL and one control Fab with irrelevant specificity (Fig. 1a).

Results: We validated the binding affinity of the constructs to LDL with surface plasmon resonance (Fig. 1b) and confirmed that IL-10 retains its bioactivity in vitro. We then conducted a screen of these constructs in hypercholesterolemic apolipoprotein E^-/- mice. Our results showed that the total number of immune cells in the aorta was significantly reduced in the group treated with 2D03-IL-10 (Fig. 1c). The number of macrophages which contribute to plaque formation was similarly reduced. Importantly, neither wild type (WT) IL-10 nor IL-10 fused to the irrelevant Fab (IRR) showed any reduction of aortic immune cell infiltration.

Conclusions: We used biomolecular engineering techniques to target the cytokine IL-10 to atherosclerotic plaques. The 2D03-IL-10 fusion protein resulted in reduced vascular inflammation and has the potential to improve atherosclerosis disease outcomes.