Types of Immune System


Immunity is the ability of the body to defend itself against disease-causing organisms. Everyday our body comes in contact with several pathogens, but only a few results into diseases. The reason is, our body has the ability to release antibodies against these pathogens and protects the body against diseases. This defence mechanism is called immunity.

Immune System consists of different types of cells and organs which protect our body against pathogens. Pathogens are defined as everything that does not belong to our body, from parasites to fungi, bacteria, viruses, and haptens. Haptens are molecules that may cause an immune response when comes in contact with a protein. All these cells and molecules are distributed in all the tissues of the body as well as lymphoid organs which eliminate or prevent microbial infectious diseases, decrease the growth of tumours and starts the repairing process of damaged tissues.


Sometimes the immune system attacks its own tissues and organs instead of the foreign agents. This is called autoimmunity. Type I diabetes is an example of autoimmune disease.

Types of Immune System

We, humans, have two types of Immune System and are classified based on its resistance power against the infectious agents.

  • Innate Immune System.
  • Adaptive Immune System.

Innate and Adaptive Immune System

Immune System fights against microbes. Innate Immune System is composed of cells and proteins that are always present and are ready to fight against microbes in the infection area. Innate Immune System is present from the time of our birth Main elements of the innate immune system are –

  • Dendritic cells.
  • Phagocytic leukocytes.
  • Natural killer (NK) cell.
  • Physical epithelial barriers.
  • Circulating plasma proteins.

Adaptive Immune System

The Adaptive Immune System is required to fight against pathogens that cannot be controlled by innate immune defences. It is also referred to as the Acquired Immune System because it is acquired during the course of life. All the components of the adaptive immune system are generally inactive however when activated; these components adjust to the presence of all the infectious agents by proliferating and developing a potent mechanism for eliminating the microbes. Two Types of adaptive responses are – humoral immunity moderated by antibodies which are developed by B lymphocytes and cell-mediated immunity, moderated by T Lymphocytes.

Symptoms of Immune Dysfunction

  • Bowel disorders.
  • Parasite infections.
  • Candida overgrowth.
  • Allergies and Asthma.
  • Frequent colds and flu.
  • Autoimmune disorders.
  • Painful joints and muscles.
  • Herpes (cold sore) outbreak.
  • HPV and abnormal PAP smears.
  • Rhinitis or a constant runny nose.
  • Psoriasis, eczema, hives or rashes.

Immunology Techniques

This is an experimental method used for studying the structure and functions of the immune system. There are different techniques, which includes:

  • ELISA.
  • Immune cell isolation.
  • Immuno-histo-chemistry.
  • Generation of Antibodies.
  • Immuno-blotting and precipitation.
  • Isolation and Purification of Antibodies.

Applications Of Immunology

Immunology is widely used in numerous disciplines, including medicine, in the fields of organ transplantation, bacteriology, oncology, virology, parasitology, rheumatic diseases, psychiatric disorders, and dermatology. The Immunology of transplantation mainly deals with the process of transplantation from a donor to the recipient, so that the recipient’s body does not reject the organ.