Preface

Infections are immune-mediated illnesses that can range from mild to serious. In recent years, new pathogens have appeared, such as the COVID-19 virus, which caused a worldwide pandemic. Due to the appearance of new and serious pathogens, the human immune response is continually being tested.

Phagocytosis is one of the main mechanisms in innate immune defense and the first process to respond to pathogens. It is also one of the initiating branches of an adaptive immune response. In the immune system, the cells that are capable of phagocytosis are called "professional phagocytes." These include neutrophils, macrophages, monocytes, dendritic cells, and eosinophils. In these cells, the phagosome is the organelle formed by phagocytosis of material. It then moves toward the centrosome of the phagocyte and is fused with lysosomes, forming a phagolysosome and leading to degradation. Progressively, the phagolysosome is acidified, activating degradative enzymes and killing all pathogens.

This book discusses the main aspects of phagocytosis and related cells in the human immune response. It also examines the molecular mechanisms involved in infections and related pathogens, providing a comprehensive review of infectious diseases and their pathophysiology, diagnosis, management, and treatment.

As educators, we are frequently faced with probing questions from students who are confused by the paradoxical functions of the immune system. We think this book can help students to understand the molecular pathways of phagocytosis. Thus, it is a useful resource not only for undergraduate and graduate students but also for immunology specialists and clinicians.
