Structure and Function of the Immune System
All defense reactions of the body develop on the basis of the lymphatic system, which serves as the morphological foundation of immunity. The effector elements of the system are divided into two categories:
- Cellular factors: specialized T and B lymphocytes, as well as phagocytes.
- Humoral factors: antibodies, complement system proteins, interferons, and other soluble substances.
The main principle of immune function is the close cooperative interaction of all these elements. The primary mechanism of action always consists of two stages:
- Fine discrimination: flawless recognition of "self" and "non-self".
- Physical destruction, neutralization, or elimination of the identified foreign agent.
Classification of Defense Targets (Antigens)
The immune system reacts to any substances carrying signs of genetic foreignness. In immunology, they are called antigens (from Greek anti — against, genes — birth/origin). All antigens are divided into two large groups depending on their origin within the body.
Exogenous antigens (introduced from outside):
- Various microorganisms (bacteria, viruses, and other pathogens).
- Antigens of plant and animal origin.
- Chemically synthesized substances.
Endogenous antigens (generated inside the body):
- Autoantigens (the body's own tissues that have become targets).
- Specific tumor antigens.
- Products of cellular and molecular mutations that the immune system must timely recognize and destroy.
Clinical Significance and Current Directions
Modern immunology has long gone beyond fighting microbes alone. Today, its achievements are critical for a wide range of medical disciplines. It addresses infectious diseases, allergology, and plays a key role in transplantology (organ and tissue transplantation) and oncology (tumor diagnosis and treatment).
Among the most relevant and complex areas of clinical immunology are:
- Immunological conflicts: study and prevention of incompatibility between the maternal organism and the fetus during pregnancy.
- Immunodeficiencies: development of prevention and therapy methods for both congenital and acquired forms of immune insufficiency.
- Genetic technologies: implementation of gene therapy and gene prevention methods for severe diseases associated with immune system disorders.