Abstract
Macrophages play an important role in tissue homeostasis and initiation and regulation of inflammation. These cells sample and react to their environment in a tissue-dependent manner, exploit their arsenal of degrading enzymes to effectively eliminate endocytic and phagocytic cargo, and secrete a wide range of mediators. Dendritic cells enjoy the central stage in autoimmunity research aiming to understand how self-antigens are presented in an immunogenic fashion. Dendritic cells and macrophages are both mononuclear myeloid cells and share numerous characteristics including a highly developed endocytic compartment, expression of a wide range of sensing receptors termed pattern recognition receptors, and ability to migrate and respond to their environment. Both cells are professional antigen presenting cells but, from a functional point of view, dendritic cells are endowed with the capacity to activate naïve T cells. Macrophages, in contrast, interact with activated T cells during inflammation and, as such, act as effector and regulatory cells during T cell-mediated inflammatory responses. It is also plausible that dysregulated antigen presentation takes place in the context of genetic abnormalities in intracellular sensing pathways of macrophages linked to autoinflammatory diseases. In this context, the lower threshold of macrophage activation and associated inflammation could provide the setting for the release and modification of self-antigens that can then be internalized and presented by activated dendritic cells. This chapter will first provide a general overview of macrophage biology focusing on macrophage heterogeneity, receptors used by macrophages to survey their environment, and the phagocytic process. Because of the importance of self-recognition in the induction of autoimmune diseases, special mention will be made of endogenous activators and inhibitors of macrophage receptors and the process of apoptotic cell clearance.
Original language | English |
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Title of host publication | The Autoimmune Diseases |
Publisher | Elsevier |
Pages | 191-212 |
Number of pages | 22 |
ISBN (Electronic) | 9780128121023 |
ISBN (Print) | 9780128122426 |
DOIs | |
State | Published - 01 01 2019 |
Bibliographical note
Publisher Copyright:© 2020 Elsevier Inc. All rights reserved.
Keywords
- Apoptosis recognition
- Endocytosis
- Inflammation
- Lectin receptor
- Pattern recognition receptors
- Phagocytosis