Immunology-Definition, Types, and Importance

Immunology is the study of how our immune system works. It is a branch of Biology that focuses on the body’s defense mechanisms against foreign invaders. It examines how the immune system functions in health and disease, and how the immune system malfunctions in disorders like allergies, autoimmune diseases, and transplants.

Immune System-Innate And Adaptive Immunity

A system that works to protect our body against germs or foreign particles that can harm our body is called the immune system.

Innate Immunity

The defense against foreign invaders is called the innate immune system. Innate means “built-in” or “natural.” The innate immune system includes physical barriers (skin, mucous membranes), chemical barriers (saliva, tears, urine), cellular components (white blood cells), and humoral factors (complement). The innate immune system is designed to protect us from bacteria, viruses, fungi, parasites, and toxins.

The innate immune system consists of two parts: the nonspecific and specific systems. The nonspecific system is composed of phagocytic white blood cells (neutrophils, monocytes, macrophages) and complement. The specific system involves antibodies and antigen receptors. Antibodies are produced by B lymphocytes, while antigen receptors are expressed on T lymphocytes.

Antigen receptors recognize antigens that have been introduced into the body. When an antigen receptor recognizes its corresponding antigen, it triggers a cascade of events that results in the production of antibodies. Antibody molecules bind to antigens and mark them for destruction by phagocytic cells.

The innate immune response is triggered by the recognition of pathogen-associated molecular patterns (PAMPs). PAMPs are molecules that are unique to pathogens and not present in humans. Examples of PAMPs include lipopolysaccharide (LPS) from gram-negative bacteria, flagellin from bacterial flagella, peptidoglycan from gram-positive bacteria, double-stranded RNA from viral infections, and unmethylated CpG DNA from bacteria. Recognition of these PAMPs activates the innate immune system.

Innate immunity provides protection against many types of microorganisms. However, the innate immune system does not provide long-term protection against infection.

Adaptive Immunity

To prevent reinfection, the adaptive immune system must develop. Adaptive immunity develops after exposure to an infectious agent. The adaptive immune system uses acquired immunity. Acquired immunity requires prior exposure to an organism. After exposure, memory cells are created that allow for faster and stronger responses upon re-exposure to the same organism.

The adaptive immune system consists of three branches: humoral immunity, cellular immunity, and mucosal immunity. Humoral immunity produces antibodies that neutralize microbes and activate complement. Cellular immunity destroys infected cells via cytotoxic T cells and natural killer cells. Mucosal immunity prevents the entry of organisms at mucosal surfaces.

Humoral Immunity

Humoral immunity is mediated by B lymphocytes. B lymphocytes produce antibodies that bind to antigens. Antibodies are secreted into the bloodstream where they circulate until they encounter their target. Antibodies attach to antigens and signal the phagocytic cells to destroy the antigen.

Antibodies are classified according to their specificity. Monoclonal antibodies are highly specific and are derived from hybridoma cells. Polyclonal antibodies are less specific and are derived from serum. Both monoclonal and polyclonal antibodies are used therapeutically.

Cellular Immunity

T lymphocytes play an important role in cellular immunity. There are two types of T cells, the helpers T cells, and the cytotoxic T cells. T cells can increase the production of B lymphocytes. T cells kill cells that are in contact with them.

Mucosal Immunity

Mucosal immunity is mediated by IgA-producing plasma cells. IgA binds to antigens and blocks their passage across mucosal epithelia.

Who Is The Father Of Immunology?

Louis Pasteur is known as the father of immunology. Pasteur’s research in the late 19th century popularized the germ theory of disease and the hope that all infectious diseases could be prevented by prophylactic vaccination made him the pioneer of modern immunology.

What Is An Immunologist?

An immunologist is someone who studies how the immune system works.

Clinicians who work with Immunology and hematology also work as researchers, educators, and consultants in both clinical and laboratory settings. Immunologists look at the diagnosis and management of immune diseases, such as autoimmune diseases and immunodeficiency disorders.

He is a physician who specializes in the diagnosis, treatment, and management of allergies and asthma. The doctor is also trained to diagnose, treat, and manage immunologic disorders.

Types Of Immunology

Immunology is categorized into following types based:

Diagnostic Immunology

Diagnostic immunology involves the study of the relationship between antigens and antibodies for the diagnosis of diseases. Immune methods are used as tools in the treatment and prevention of infectious diseases and immune-mediated diseases.

Clinical Immunology

clinical Immunology is the study of diseases that occur when the immune system fails or grows abnormal. There are diseases of other systems where the immune system plays a role in causing or modifying the disease.

Eco immunology

Ecoimmunology explores the relationship between the immune system of organisms and their environment.

Cancer Immunology

Cancer immunology is The study of the interaction between the immune system and cancer cells. It can lead to diagnostic tests and treatments to find and fight cancer. Cancer immunology is the branch of immunology that focuses on the immune system’s reactions to cancer and the interactions between cancers and the body’s immunity.

Reproductive Immunology

Referring to the study of immunological aspects of the reproductive process is called reproductive immunology. In reproductive immunology, Fetus acceptance is also studied.

Developmental Immunology

There are a lot of factors that affect the development of the human immune system. These factors are being studied in the field of developmental immunology. Immune cells are established and interact with foreign cells.

Famous Immunologist

• Shizuo Akira
• Elias Metchnikff’s
• Robert Royston Amos
• Deborah Doniach
• John H. Humphrey
• Sir Peter Medawar
• Dame Bridget Ogilvie
• Delphine Parrott
• Rodney Robert Porter

Latest Research About Immunology

• Scientists have studied Host Defense Peptides (HDPs) and their role in the immune system. HDPs have diverse functions and can be regulated by nutrients and disease. This review explores the regulation of HDP expression and its potential for protecting host health in nutrition and disease. [1]
• Scientists have created ImmCluster, a resource for clustering and annotating immune cells in normal and cancerous tissues. It offers marker gene sets, computational methods for clustering, and analytic modules for exploring immune cell annotations. [2]
• Scientists acknowledge the progress made in COVID-19 research and therapies, including unprecedented advancements in vaccine technologies and decoding human immunology. However, they caution against complacency and recognize the challenges ahead. [3]