What is the Difference Between Endogenous and Exogenous Antigens?
🆚 Go to Comparative Table 🆚The main difference between endogenous and exogenous antigens lies in their origin and location within the body.
- Endogenous antigens are found within the cytosol of human cells, such as viral proteins, proteins from intracellular bacteria, and tumor antigens. These antigens are generated due to cell metabolism or viral or intracellular bacterial infection.
- Exogenous antigens enter the body from the outside, such as bacteria, fungi, protozoa, and free viruses. These antigens can enter the body through inhalation, ingestion, or injection and are typically found in foreign substances.
Both endogenous and exogenous antigens can stimulate an immune response, but the manner in which they are presented to the immune system differs. Endogenous antigens need to be presented to the immune system via specialized cells called antigen-presenting cells (APCs), which include dendritic cells, macrophages, and B cells. In contrast, exogenous antigens can be recognized by the immune system directly upon entering the body.
Comparative Table: Endogenous vs Exogenous Antigens
The main difference between endogenous and exogenous antigens lies in their origin. Here is a table comparing the two types of antigens:
Feature | Endogenous Antigens | Exogenous Antigens |
---|---|---|
Origin | Generated within the cells | Enter from outside the body |
Examples | Self-antigens, tumor antigens, alloantigens, some viral antigens | Bacteria, fungi, protozoa, viruses, and other infectious agents |
Processing | Processed within the cell's cytosol | Processed in endocytic compartments |
Presentation | Presented on MHC class I molecules by antigen-presenting cells (APCs) | Presented on MHC class I molecules by APCs, such as dendritic cells |
Endogenous antigens are generated within the cells due to cell metabolism, viral infections, or intracellular bacterial infections. On the other hand, exogenous antigens enter the body via inhalation, ingestion, or injection from outside sources, such as bacteria, viruses, fungi, protozoa, and helminths. Both types of antigens can induce an immune response, leading to the production of antibodies and activation of T cells.
- Endotoxin vs Exotoxin
- Self vs Non Self Antigens
- Exogenous vs Endogenous Budding
- Antigen vs Pathogen
- Allergen vs Antigen
- Hapten vs Antigen
- Antigen vs Immunogen
- A vs B Antigens
- Antigen vs Antibody
- O vs H Antigen
- Endotoxin vs Enterotoxin
- T Cell Dependent vs Independent Antigens
- Exoenzyme vs Endoenzyme
- Endosymbiont vs Endophyte
- Endotoxin vs Pyrogen
- Antigen vs Antibody Test
- Major vs Minor Histocompatibility Antigens
- Endocytosis vs Phagocytosis
- Innate vs Adaptive Immunity