Preface

Macrophages are an essential player of the immune system and have been extensively studied and written about. Many aspects of macrophage biology have been discussed in recent works; however, the field is evolving at such a rapid pace that keeping up with the latest information is a challenging task. The current book is therefore intended to provide the reader with an account of the latest knowledge and developments in the field of macrophage biology. Ever since their discovery by lya Ilyich Mechnikov in 1882, these cells have intrigued the scientific community and provided fascinating insights in understanding general immunobiology as well as presented efficient therapeutic targets to translational research scientists. Macrophages represent an efficient homeostatic and protective system that evolved early in the evolution process. As a first line of defence they not only provide protection from pathogens but also play a role in the development and regulation of the immune system. They process and present the antigenic determinants to adaptive immune system to initiate a longlasting memory against the encountered insult. In addition to this, macrophages possess a memory of their own which, though short lived, is included in their genetic makeup.

Macrophages are heterogenous in their function as well as phenotypes. Although they are endowed with a repertoire of receptors and efficient metabolic machinery, in response to environmental cues, macrophages adjust their expression patterns to efficiently clear the pathogenic microbes and dead materials as well as remodel the tissues to initiate the regeneration process. The phenomenon has been termed macrophage plasticity and is discussed in a few chapters in different contexts. Macrophage plasticity has been associated with many pathological conditions and is therefore an attractive target for drug development and therapeutic interventions. Macrophages play a critical role in development and dissemination of cancer. On one hand, they provide a suitable environment for angiogenesis and development of tumours and on the other hand they help in the dissemination of the cancerous cells to healthy parts of the body. Given our current knowledge about the macrophages associated with various pathological conditions like tumours, infectious diseases, autoimmune and metabolic disorders, we can develop efficient therapeutic interventions targeting macrophage activation and polarization. In addition to conventional pharmacological approaches, many traditional approaches like Chinese medicine are being used to modulate the macrophage plasticity for a favourable outcome. Some remarkably promising results have been reported, few of which have been discussed in this book.

This book covers a broad array of topics from reputed biologists from different parts of the World and from varied fields of research. Emphasis has been given to the current developments in the field and an in-depth analysis has been provided for each topic discussed. The scope of the topics covered encompass the basic as well as applied areas of macrophage research.

I am very thankful to all the authors who have done a commendable job in bringing this book to existence. I also thank the staff at IntechOpen without whose cooperation the publication would have been a daunting task.

**Khalid Hussain Bhat, PhD.**

Assistant Professor, Division of Basic Science and Humanities, Faculty of Agriculture, Sher-e-Kashmir University of Agriculture Science and Technology, Jammu and Kashmir, India

## Chapter 1
