Intro to the Immune System Flashcards
What are the characteristics of innate immunity?
Rapid, no memory, recognises molecular patterns associated with danger
What are the components of innate immunity?
physical barriers, antimicrobial chemicals, complement, epithelial cells, phagocytes, natural killer cells, cytokines
What are the characteristics of acquired immunity?
recognises antigens, slower response, memory
What are the components of acquired immunity?
lymphocytes (T cells and B cells), antibodies, cytokines
What are PAMPs?
PAMPs are pathogen associated molecular patterns - that is conserved molecular patterns found on microorganisms such as unmethylated DNA or polysaccharides
What are PRRs?
PRRs are pattern recognition receptors - these are the receptors present on immune cells to detect PAMPs. Some examples are toll like receptors (TLRs), NOD like receptors (NLRs), RIG like helicases, collections, scavenger receptors
What are DAMPs
DAMPs are danger associated molecular patterns - these are molecular patterns produced in the body during disease or trauma that are recognised by PRRs
What are antigens?
Antigens are unique molecules that can be recognised by the immune system - cells of the adaptive immune system have receptors for antigens
What are some extracellular PRRs?
TLR1,2,4,5,6, Dectin-1, MR
What are some cytoplasmic PRRs?
TLR 3,7,9, RLH, NLRs
What is the structure of antigen receptors?
In both BCR and TCR, there are 2 regions. A constant region and a variable region. The variable region is where the antigen binds.
Where do T cells develop?
The thymus
Where do B cells develop?
The bone marrow
What is a cytokine?
A cytokine is a protein secreted by cells which interacts with nearby cells with the appropriate receptor
What is a chemokine?
A chemokine is a protein which attracts cells with appropriate receptors to a certain area
In the absence of infection where do you find lymphocytes?
Circulating between the blood and secondary lymphoid organs (spleen, lymph nodes, mucosal associated lymphoid tissue)
Where do microbes bind to T and B cells?
In secondary lymphoid tissue - the microbes are carried there via the lymphatics to activate the T and B cells
How to active T and B cells get to the site of infection?
Via the blood
Where do lymph nodes sample antigens from?
The skin and internal tissue
Where does the spleen sample antigens from?
The blood
Where does the mucosal associated lymphoid tissue sample antigens from?
Mucosal tissue
In which part of the lymph nodes are the B cells?
The cortex
In which part of the lymph nodes are the T cells?
The medulla
What is the function of neutrophils?
Engulfs microbes
What is the function of macrophages?
Engulfs microbes and releases cytokines
What is the function of natural killer cells?
Binds and kills infected cells and releases cytokines
What is the function of eosinophils?
Binds and kills parasites
What is the function of basophils?
release inflammatory mediators and cytokines
What is the function of dendritic cells?
presents antigen to T cells and releases cytokines
What is the function of B cells?
To secrete antibodies
What is the function of CD8 T cells?
To bind and kill infected cells
What is the function of CD4 T cells?
To help macrophages, B cells and CD8 T cells
