I.

Introduction

Monoclonal Antibody (MAb), laboratory-produced protein molecule used in medicine to detect pregnancy; diagnose disease, including acquired immunodeficiency syndrome (AIDS), hepatitis, and various kinds of cancer; and treat conditions caused by toxins, or poisonous substances, such as snake venom. When MAbs were first discovered in the 1970s, scientists expected them to revolutionize the way diseases like cancer are treated. Over 20 years later, MAbs best serve medicine as diagnostic tools and treatment aids—that is, in combination with more conventional therapies. They are also used in laboratories to track proteins in experiments.

An antibody is a Y-shaped protein produced by a type of white blood cell known as a B cell. B cells are made in the bone marrow of the body and then travel to such organs as the spleen and the lymph nodes. Mature B cells respond to foreign substances called antigens. They then differentiate into plasma cells, which secrete antibodies. Antibodies neutralize or mark antigens for destruction with the help of other cells of the immune system—the system of organs, tissues, cells, and cell products, including antibodies, responsible for ridding the body of disease-causing organisms or substances. Antibodies perform their work by attaching, or binding, to specific parts of antigens. Only antibodies created for a specific antigen can attach to that antigen. Once an antibody is produced, it circulates in the blood, ready to attack its targeted antigen the next time the antigen invades the body. As a result, the blood contains thousands of different types of antibodies.