Objective: Atherosclerosis is a condition that is increasingly contributing to worldwide mortality through complications such as stroke and myocardial infarction. IL-1β plays multiple direct, local roles in the formation and stability of the atheroma by eliciting the production of additional cytokines and proteolytic enzymes from macrophages, endothelial cells (EC) and smooth muscle cells (SMC). We therefore tested whether an anti-IL-1β antibody, XOMA 052, might inhibit the secretion of pro-atherogenic cytokines from macrophages in vitro and affect a positive outcome in the Apolipoprotein E-deficient mouse (ApoE(-/-)) model of atherosclerosis in vivo.
Methods and results: In an in vitro co-culture model, XOMA 052 inhibited macrophage-induced secretion of key atherogenic cytokines from EC and SMC, including IL-6, IL-8, MCP-1 and TNFα. The release of degradative enzymes, such as the matrix metalloproteinases MMP-3 and MMP-9, was also decreased by XOMA 052. In addition, XOMA 052 inhibited the secretion of IL-7 from EC and IL-4 from SMC, cytokines not previously reported to be driven by IL-1β in this context. In vivo, XMA052 MG1K, a chimeric murine version of XOMA 052, inhibited the formation of atherosclerotic lesions in the ApoE(-/-) model at all three doses tested. This effect was comparable to that reported for complete genetic ablation of IL-1β or IL-1R1 on an ApoE(-/-) background and was associated with decreases in plasma non-HDL/HDL cholesterol ratio and plaque lipid content and macrophage infiltration.
Conclusions: These results demonstrate for the first time that an antibody targeting IL-1β can inhibit the progression of atherosclerosis in vivo, highlighting the importance of this key cytokine in cardiovascular disease.
Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.