What is the Difference Between Antigenicity and Immunogenicity

The immune system is a complete network of organs, cells, and proteins. It defends the human body against infections. The immune system keeps a record of every infectious microbe it has been ever recognized previously and defeated. Antigenicity and immunogenicity are two phenomena associated with the immune system.

What is the difference between antigenicity and immunogenicity? Antigenicity is the ability of chemical structures to specifically combine with the final products of the immune response, such as secreted antibodies or surface receptors on T cells, while immunogenicity is the ability of foreign substances to induce a humoral or cell-mediated immune response by the immune system.

CONTENTS

1. Overview and Key Difference
2. What is Antigenicity  
3. What is Immunogenicity
4. Similarities – Antigenicity and Immunogenicity
5. Antigenicity vs Immunogenicity in Tabular Form
6. Summary – Antigenicity vs Immunogenicity
7. FAQ: Antigenicity and Immunogenicity

What is Antigenicity?

The immune system typically reacts and responds to pathogens such as bacteria and viruses. It clears these foreign invaders from the human body, preventing the diseases they may cause. There are two main mechanisms for this purpose: the innate immune system (mounts a nonspecific and rapid attack) and the adaptive immune system (slower but more specific and efficient).

Antigenicity is a property of antigens. It is the ability of antigens to specifically combine with the final products of the immune response. Therefore, antigens with antigenicity effectively bind to components of the adaptive immune system. However, antigenicity generally does not characterize how well antigens stimulate an immune response. Antigenicity only describes how well antigens bind to adaptive immune system components.

What is Immunogenicity?

Immunogenicity is the ability of an antigen to provoke an immune response (humoral or cell-mediated) in the body of a human or other animals. It can be wanted or unwanted. Wanted immunogenicity normally relates to vaccines, whereas unwanted immunogenicity is an immune response by an organism against a therapeutic antigen. Immunogenicity is a critical aspect of vaccine development. Immunogenicity characterizes how well antigens stimulate an immune response.

Immunogenicity should be investigated in a target population. This is because animal testing and in-vitro models cannot precisely predict an immune response in humans. Moreover, immunogenicity data from high-income countries are not always transferable to low-income and middle-income countries.

What are the Similarities Between Antigenicity and Immunogenicity?

1. Antigenicity and immunogenicity are two phenomena associated with the immune system.
2. Both phenomena describe how well the immune system works.
3. They are reactions against antigens and immunogens, respectively.
4. Both phenomena can be seen in humans as well as in other animals.

Comparing the Difference Between Antigenicity and Immunogenicity

Definition

1. Antigenicity is the capability of an antigen or hapten to bind specifically with a group of certain products that have adaptive immunity, like T cell receptors or antibodies.
2. Immunogenicity is the ability of a complete antigen to induce an immune response in the human body or other animals’ bodies.

Stimulating An Immune Response

1. Antigenicity does not characterize how well antigens stimulate an immune response.
2. Immunogenicity characterizes how well antigens stimulate an immune response.

Substance

1. Antigens produce antigenicity.
2. Immunogens produce immunogenicity.

Examples

1. 1. Lipids, polysaccharides, nucleic acids, and proteins induce antigenicity.
   2. Large polysaccharides and proteins induce immunogenicity.

The following table summarizes the difference between antigenicity and immunogenicity.

Summary – Antigenicity vs Immunogenicity

Antigenicity and immunogenicity are two phenomena associated with the immune system. Both phenomena describe how well the immune system works. However, antigenicity is the ability of antigens to specifically combine with the final products of the immune response, such as secreted antibodies or surface receptors on T cells. Immunogenicity is the ability of foreign substances, such as complete antigens, to induce a humoral or cell-mediated immune response by the immune system. Thus, this is the summary of the difference between antigenicity and immunogenicity.

FAQ: Antigenicity and Immunogenicity

1. What are the two attributes of antigenicity?

1. • Immunogenicity and allergenicity are the two attributes of antigenicity.  Immunogenicity refers to the ability to trigger an immune response, while allergenicity relates to the potential to induce allergic reactions.

2. What are antigenic determinants?

1. • Antigenic determinants are regions of proteins that can trigger a cellular immune response mediated by T or B cells. These regions play a crucial role in the recognition and interaction between antigens and the cells of the immune system.

3. What is an example of antigenicity?

1. • An example of antigenicity is the body’s immune response to a flu virus. When the flu virus enters the body, it stimulates the immune system to produce antibodies specific to that virus, helping to fight off the infection.

4. What is the difference between immune response and immunogenicity?

1. • The immune response is the body’s reaction to foreign substances, such as pathogens. On the other hand, immunogenicity refers to the ability of a substance to induce an immune response.

5. What are antigenic but not immunogenic?

1. • Haptens are antigenic molecules that can bind to antibodies but are not immunogenic on their own. They become immunogenic only when they are attached to a carrier protein or larger molecule.

Reference:

1. “Immunogenicity – An Overview.” ScienceDirect Topics.
2. Baker, Matthew P, et al. “Immunogenicity of Protein Therapeutics: The Key Causes, Consequences and Challenges.” Self/Nonself, U.S. National Library of Medicine.

Image Courtesy:

1. “Antibody” By Fvasconcellos 19:03, 6 May 2007 (UTC) – Color version of Image:Antibody.png, originally a Work of the United States Government (Public Domain) via Commons Wikimedia
2. “Factors affecting Immunogenicity of Monoclonal Antibodies” By Immcarle106 – Own work (CC BY-SA 4.0) via Commons Wikimedia