An introduction to immunology and immunopathology

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Marshall et al.  

Allergy Asthma Clin Immunol 2018, 14(Suppl 2):49

https://doi.org/10.1186/s13223-018-0278-1

REVIEW

An introduction to immunology 

and immunopathology

Jean S. Marshall

1*

, Richard Warrington

2

, Wade Watson

3

 and Harold L. Kim

4,5

Abstract 

Beyond structural and chemical barriers to pathogens, the immune system has two fundamental lines of defense: 

innate immunity and adaptive immunity. Innate immunity is the first immunological mechanism for fighting against 

an intruding pathogen. It is a rapid immune response, initiated within minutes or hours after aggression, that has 

no immunologic memory. Adaptive immunity, on the other hand, is antigen-dependent and antigen-specific; it 

has the capacity for memory, which enables the host to mount a more rapid and efficient immune response upon 

subsequent exposure to the antigen. There is a great deal of synergy between the adaptive immune system and its 

innate counterpart, and defects in either system can provoke illness or disease, such as inappropriate inflammation, 

autoimmune diseases, immunodeficiency disorders and hypersensitivity reactions. This article provides a practical 

overview of innate and adaptive immunity, and describes how these host defense mechanisms are involved in both 

heath and illness.

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(

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Background

There are continuous advances in our current 

understanding of the immune system and how it 

functions to protect the body from infection. Given the 

complex nature of this subject, it is beyond the scope of 

this article to provide an in-depth review of all aspects 

of immunology. Rather, the purpose of this article is to 

provide medical students, medical residents, primary-

care practitioners and other healthcare professionals 

with a basic introduction to the main components and 

function of the immune system and its role in both health 

and disease. This article will also serve as a backgrounder 

to the immunopathological disorders discussed in the 

remainder of this supplement.