Potential use of dendritic cells for anti-atherosclerotic therapy

The chronic inflammatory nature of atherosclerosis is nowadays widely accepted. Dendritic cells (DCs) are likely to play a crucial role in directing innate and adaptive immunity against altered (self-)antigens, such as oxidized low density lipoproteins (oxLDL). DCs are found in early lesions and their numbers become even higher when the lesion progresses. DCs are most abundant in areas of neovascularization where they are often found near T cells. All stages from precursors to fully mature DCs are present in human plaques. Treatment of atherosclerosis is currently based on reducing risk factors, e.g. by use of statins and beta-blockers. Some of these pharmacological agents also show anti-inflammatory properties and consequently can affect DC function. Yet, many patients remain at risk for acute coronary events, and new therapies to treat atherosclerosis are needed. One therapeutic strategy is based on isolation of patient's DCs that are then pulsed with appropriate antigen(s) ex vivo, e.g. (immunogenic components of) oxLDL or total extract of atherosclerotic plaque tissue, and returned to the blood stream. Other approaches to ensure immune protection include generation of tolerogenic DCs, or using DCs to deplete detrimental Th1 or Th17 cells. However, the future lies in direct targeting of DCs by manipulating functions of different DC subsets. Therefore, it would be useful to isolate plaque-resident DCs to be able to identify unique antigen(s) on their surface. The challenge is to selectively identify regulatory molecules and novel therapies to inhibit DC migration and function during atherogenesis, without affecting normal DC function under physiological conditions.