Methods to Study Monocyte and Macrophage Trafficking in Atherosclerosis Progression and Resolution.

Monocytes are circulating cells imperative to the response against pathogens. Upon infection, they are quickly recruited to the affected tissue where they can differentiate into specialized phagocytes and antigen-presenting cells. Additionally, monocytes play a vital role in chronic inflammation, where they can promote and enhance inflammation or induce its resolution. There are two major subsets of monocytes, "inflammatory" and "nonclassical," which are believed to have distinct functions. In atherosclerosis, both types of monocytes are constantly recruited to lesions, where they contribute to plaque formation and atherosclerosis progression. Surprisingly, these cells can also be recruited to lesions and promote resolution of atherosclerosis. Tracking these cells in various disease stages may inform about the dynamic changes occurring in the inflamed and resolving tissues. In this chapter we will discuss methods for differential labeling of the two monocyte subsets in order to examine their dynamics in inflammation.