What Is Exogenous Antigen

Exogenous antigens are antigens that have entered the body from the outside, for example, by inhalation, ingestion or injection. The immune system’s response to exogenous antigens is often subclinical.

What is the difference between exogenous and endogenous antigen processing?

The key difference between endogenous and exogenous antigens is that the endogenous antigens generate within the cells while the exogenous antigens come from the outside of the body. Hence, endogenous antigens are intracellular while exogenous antigens are extracellular.

What is an example of an exogenous antigen?

Exogenous antigens include particles considered foreign within the organism. For example, allergens (such as pollen), proteins from transplanted tissues and organs, and parts of microorganisms (such as coat, capsule, cell wall, flagella, fimbria, or toxin of bacteria, viruses, etc.)