Macrophage development and polarization in chronic inflammation

Overview

An inflammatory response is a localized, nonspecific immune reaction that occurs when a tissue is injured. It is characterized by redness, swelling, heat, and pain, which are commonly called the cardinal signs and symptoms of inflammation. Inflammation can sometimes result in a loss of function.
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...

Immune surveillance is an integral part of the innate immune system, involving the continuous monitoring of peripheral tissues to detect and respond to pathogens, infected cells, or cancerous cells. This surveillance is conducted primarily by natural killer (NK) cells and phagocytes, which employ distinct but complementary mechanisms to identify and eliminate threats.
Natural Killer Cells: The Fast Responders
NK cells are large granular lymphocytes found in the blood and lymphatic system. These...

Common myeloid progenitors (CMPs) are oligopotent cells that can differentiate into granulocytes and macrophages. Granulocytes and macrophages are essential for protecting the body against bacterial, viral, or fungal infections. They migrate from the bone marrow into the circulating blood to reach specific tissue sites where they differentiate and help in immune surveillance. However, they survive only for a few days and must be continuously made available to the organism to maintain a robust...