Introduction to immunology Flashcards
Define immunity
A state of protection from pathogens
What is the main way immunity happens?
Immune system
What are the roles of the immune system?
Provide immunity to the host
Recognise self
Growth and repair
Protection from tumours
What are the two branches of the immune system?
Innate
Adaptive
Distinguish between the innate and the adaptive immune system
The innate immune system is the first line of defense and is inherited.
The adaptive immune system is not the same throughout life
What are some contributors of the innate immune system?
Outer defences
Macrophages and neutrophils
NK cells
Complement
Intrinsic immunity
What are some of the contributors of the adaptive immune system?
T cells
B cells
How is the adaptive response different to the innate response?
The adaptive immune response is specific and confers immunological memory
How do NK cells destroy their targets?
Contact dependent mechanism of tumour cells and virally infected cells
What is intrinsic immunity?
Any process in the cell
Since they all prevent viral infection
What is immunological memory?
Allows a quicker response upon reinfection
How are the innate and adaptive immune system related?
Through communication mechanisms like cytokines
When is the immune system turned on?
The immune system is constantly active
This is part of the normal physiology of humans
We are constantly exposed to many environmental factors
What are the 3 Rs of the immune system?
Recognition
Response
Regulation
Describe how the immune system recognises pathogens
Innate system through PAMPs and DAMPs
Adaptive system through BCR and TCR
What are PAMPs?
Sugars and proteins released by pathogens which are shared across different families
What are DAMPs?
Normal molecules found in the wrong place in the system
How are the TCR and BCR so diverse?
Due to the rearrangement of genes that encode them
How do macrophages/neutrophils destroy pathogens?
Phagocytosis
How do lymphocytes destroy pathogens?
Contact-dependent killing
What are examples of non cellular immune responses?
Antibodies
Complement
How do antibodies destroy pathogens?
Block pathogen function
Binds to pathogens and recruits cells or complement
How do complement destroy pathogens?
Lyses target cells and activates other immune cells
Forms MAC that causes the damage of membranes and leads to cell death
What are ways in which the immune system is regulated?
Multi-step activation
Professional regulatory T cells
Checkpoint proteins
What are examples of Checkpoint inhibitors?
PD1
CTLA-4
What are allergies?
Immune reactions triggered upon exposure to non-dangerous molecules
What is autoimmunity?
The immune system recognises self as foreign, leads to an inappropriate immune response
What is cancer?
T cells recognise cancer cells but don’t react through their manipulation of checkpoint proteins
What is immunodeficiency?
Genetic mutations to genes involved in the immune system can often lead to a decrease in immune function
