Immunology – an overview
Immunity: the general ability of a host to resist infections or diseases.
Immune system is composed of cells, tissues, molecules and tissues
Immune system
·Prevent access of pathogens to the body
·Ties to neutralize or eradicate infections
Immune response
·The coordinated reaction of the host’s immune system to foreign agent or pathogen.
·It involves recognition and defending strategies against the invader.
Immunology: the science within studies all the aspects of the immune system
·Its structure and function
·Immune responses to infections or diseases
·Disorders of immune system
Types of immunity
·Innate immunity
·Adaptive immunity
Innate immunity (First & second line of defense)
·Present at birth
·Determined by Genetic factors
·Also known as Native or Natural Immunity
·It provides an early defense against infections
·It recognizes and provide defense against a wide variety of infectious agents
·Recognizes structural features shared by microbes. e.g. LPS of Gram-negative bacteria
·The strategy or mechanism of defense of innate immunity is same regardless of pathogen type
·Also known as Non-specific immune response or resistance
·Responds quickly i.e. within minutes or hours
·It has no memory of encounter or immunological memory
The routes of entry for pathogens are:
1)Skin
2)Mucous membranes of respiratory tract, gastrointestinal tract, urinary tract, reproductive tract. 粘膜
First line of defense
·Components are: skin, mucous membranes and their secretions
·Prevent access of microbes into the body
Second line of defense
·Components are: phagocytes, antimicrobial substances, natural killer cells, inflammation, fever
·Destruction or elimination of microbes which penetrates the body
Adaptive immunity (Third line of defense)
·The immunity which an individual acquires during life
·Acquired after birth
·Also known as acquired immunity
·It adapts or changes accordingly
·It is highly specific in action
·Also known as specific immunity
·Immunological memory is present in acquired immunity
·It is a slower response (takes days to develop) but long-lasting immune response
Main components are:
·B lymphocytes
·T lymphocytes
·Antigen presenting cells (APCs)
Antigen
·Antigens are molecules or substances which are recognized by the immune system
·They are usually proteins, on the surface of microbes and their by-products i.e. toxins, chemicals etc.
What happens if immune system fails?
·Allergies (Immune system overreacts)
·Autoimmune diseases (Immune system attacks self)
·Immunodeficiency diseases (immune system fails to respond appropriately to a disease causing agent)
学习内容
Janeway's Immunobiology 10th Edition
Immunology - Frank Lectures
