Molecular immunology is a subfield of immunology that aims to examine immune processes at a molecular level. The immune system is the bodily system that responds to foreign entities, such as bacteria or other infectious agents in the body. The immune response that such a foreign entity triggers tends to be highly specific. The body produces antibodies that are specifically designed to target a particular antigen, or foreign body that triggers an immune response, just as a single lock tends to be matched to a single key. The field of molecular immunology exists to examine this and other aspects of immune response that are controlled at a molecular level.
The goals of molecular immunology are varied, and various techniques in the field are used in both laboratory and clinical settings. Greater understanding of the molecular basis of immune function has allowed for more targeted and effective diagnostic and treatment methods for some illnesses. It has also provided many new experimental methods to be used in molecular biology and molecular immunology laboratories. The high degree of specificity of antibodies is particularly important, as antibodies can be produced to target almost any biological component of interest. They can, therefore, be used to "tag" certain cellular components or to determine if a particular substance is present in a sample because they will bind specifically to the antigen of interest.
The interactions between antibodies and antigens are central to molecular immunology and to immunology as a whole. Various immune system cells have receptors that bind to antigens in the body and trigger an immune response. Antibodies are produced with molecular binding regions tailored specifically to the antigen of interest; they tend not to bind non-specifically to anything aside from the antigen they were made to target. Components of the immune system are also able to identify and attack cells that have been compromised, as in the case of viruses.
In addition to diseases that the immune system fights, the field of molecular immunology is also interested in diseases and disorders that affect the immune system itself. In the case of autoimmune diseases, for instance, the immune system targets "self" cells instead of antigens. In certain other disorders and diseases, the effectiveness of the immune system is reduced, thereby causing a state of immunodeficiency. Antigen recognition is driven by specific molecular mechanisms and even slight changes in the conformations of the structures of antigens can have significant effects on immune response. Scientists working in molecular immunology hope that greater understanding of the molecular basis of immunology will help them to better fight these and other diseases and disorders.