Macrophage memory: Types, mechanisms, and its role in health and disease

• Published in: Immunology Vol. 171; no. 1; pp. 18 - 30
• Main Authors: Fang, Xu‐Hui, Li, Zhi‐Jing, Liu, Chun‐Yan, Mor, Gil, Liao, Ai‐Hua
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.01.2024
• Subjects: Adaptive immunity; endowed immunity; epigenetic reprogramming; Immune system; Immunity; Immunological memory; Immunology; Immunotherapy; Innate immunity; macrophage memory; Macrophages; Phenotypes; trained immunity; Vaccines
• ISSN: 0019-2805; 1365-2567
• DOI: 10.1111/imm.13697

On the basis of the mechanisms of action and characteristics of immune effects, immunity is commonly categorized into innate and adaptive immunity. Adaptive immunity is associated with the response to non‐self‐entities and is characterized by high specificity and memory properties. In contrast, innate immunity has traditionally been considered devoid of memory characteristics. However, an increasing number of studies have sought to challenge this conventional immunological dogma and shown that innate immune cells exhibit a more robust and rapid response to secondary stimulation, thus providing evidence of the immunological memory in innate immunity. Macrophages, which are among the most important innate immune cells, can also acquire memory phenotype that facilitates the mediation of recall responses. Macrophage memory is a relatively new concept that is revolutionizing our understanding of macrophage biology and immunological memory and could lead to a new class of vaccines and immunotherapies. In this review, we describe the characteristics and mechanisms of macrophage memory, as well as its essential roles in various diseases. It is believed that the memory properties are associated exclusively with adaptive immunity. However, recent studies have sought to challenge this conventional immunological dogma and shown that innate immune cells exhibit a more robust and rapid response to secondary stimulation. There are two kinds of macrophage memory: trained immunity and endowed immunity. Macrophage memory is a relatively new concept that is revolutionizing our understanding of macrophage biology and could lead to a new class of vaccines and immunotherapies. In this review, we describe the characteristics and mechanisms of macrophage memory, as well as its essential roles in various diseases.