The interplay between lymphatic vessels and macrophages in inflammation response

Abstract

Both lymphatic vessels and macrophages are key factors influencing the inflammatory response. During the inflammatory response, lymphatic vessels undergo dilation and growth, playing a beneficial role in alleviating inflammation by facilitating the drainage of exudate, inflammatory mediators, and leukocytes. Consequently, the promotion of lymphangiogenesis has emerged as a novel therapeutic approach to treating inflammation. Macrophages play a crucial role in promoting lymphangiogenesis by secreting several pro-lymphatic growth factors, including vascular endothelial growth factor (VEGF)-C, and undergoing transdifferentiation into lymphatic endothelial cell progenitors (LECP), which integrate into newly formed lymphatic vessels. Macrophages exhibit heterogeneity and perform diverse functions based on their phenotypes. The regulation of macrophage polarization is crucial in inflammatory responses. Notably, macrophages promote lymphangiogenesis, while lymphatic vessels, in turn, serve as a conduit for macrophages to drain out inflamed tissue and also affect macrophage polarization. Thus, there is an interactive relationship between them. In this review, we discuss current work on the effects of macrophages on lymphangiogenesis as well as lymphatic vessel recruitment of macrophages and regulation of macrophage polarization. Furthermore, we explore the roles of lymphatic vessels and macrophages in various inflammation-related diseases, emphasizing potential therapeutic targets within the context of lymphatic-macrophage interactions.

Keywords: inflammation; lymphangiogenesis; lymphatic vessels; macrophages; vascular endothelial growth factor.