The Importance Of The Immune System

The Immune System

The immune system is a complex network of specialised proteins, cells, tissues and organs which work together and function as the bodies ‘defence’ mechanism. The immune system works by protecting the host from ‘foreign’ invasions by responding to pathogens which enter the body and cause diseases and/or infections, some of which are life-threatening. Immune response can be either innate or adaptive. The Innate immune system provides non-specific, structural, rapid response, whereas the response from adaptive immunity is highly specific, internal, and can take longer to kick into action. Cells of both the innate and adaptive immune system are important in enabling the body to maintain homeostasis. An immune system functioning

This, as a paradigm, will help to demonstrate the relevance and role of metabolism in the immune system. The immunometabolism in obesity involves a response called metabolically driven inflammation, also known as metaflammation. Metaflammation plays an important role in maintaining tissue homeostasis and preventing pathogenesis of metabolic diseases. This immune response, which occurs in various organs, is implicated in many diseases, not just obesity, however, as obesity is so prevalent (an epidemic in the UK and US), it has warranted the need for research to be carried out in order to discover solutions to tackle the issue itself, and to understand the secondary implications. Therefore, obesity can be found at the centre of many recent research papers on the subject of immunometabolism, so hence the reasoning for it to be the focus of this critical

Macrophages, a type of white blood cell, are immune cells which play a crucial role in the immunometabolism of many disorders, including obesity. Macrophages accumulate and infiltrate into adipose tissues; this occurs as a result of enlistment, proliferation and retention of these cells at the site of these tissues. Macrophages which reside in adipose tissue are polarized towards repair and maintenance functions when in lean adipose tissue. The fact that they have a physiological role in maintaining homeostasis in lean adipose tissue, suggests that during obesity - when under metabolic stress, they are re-configured to give an inflammatory phenotype. In summary, it is the infiltration of macrophages into adipose tissue that leads to the increased, abnormal expression of inflammatory mediators which is seen in obesity. This mechanism of immune cell infiltration was discovered by Weisberg in 2003, during a research study carried out on obese mice (Weisberg, et al., 2003). This study was important as it confirmed the mechanism behind the inflammatory phenotype associated with obesity. The study of macrophage activity has been enlightening in proving their role in immunometabolism. Macrophages secrete many pro-inflammatory cytokines and each cytokine substance has its own role in immunometabolism and