Innate and Adaptive Immunity Flashcards
Fundamental immune system
The type of immunity that everyone has
Innate
“born with it”
Innate
5 components of Innate immunity
- Barriers
- Anti-microbial peptides
- Complement
- Soluble mediators (interferon)
- Phagocytes, Granulocytes
The vast majority of the body’s immune resources are directed towards this interface
Barrier
Where can you find anti-microbial Peptides and Proteins
Often present in secretions (sweat, mucus, tears, saliva)
A type of innate immunity that is rich in positively charged aa residues
Anti-microbial Peptides and Proteins
What can anti-microbial Peptides and Proteins disrupt?
microbial membranes
What can anti-microbial Peptides and Proteins activate?
lytic proteins
What can anti-microbial Peptides and Proteins inhibit?
DNA/RNA/protein synthesis
What are anti-microbial peptides and proteins capable of doing in minutes?
Target lysis
What part of the innate immunity has a cascade effect?
Complement
What is complement a large group of?
What does it do when it recognizes a microbial cell?
Complement is a large group of soluble inactive proteins. When it recognizes a microbial cell it initiates a sequential cascade of proteolytic activation
What can you coat a target cell in so that it waves a flag
Coating of the target cell in complement protein fragments and eventual lysis
What two ways are recognition mediated in complement?
- direct binding of complement to a microbial cell surface
2. binding to antibodies that have coated a target cell
What part of the innate immune system is produced and released?
Soluble mediators
What does modulate physiology do?
Sends help signals
What part of the innate immunity indicates sickness in a blood test?
Soluble mediators
What does interferon do?
Induces a general anti-viral state
induces fevers
Non-clonal
Identical
Which part of the innate activates the adaptive?
Phagocytes and granulocytes
What part of the innate immune system does not require recognition
Barriers - keep everything out!
Does the innate immune system recognize specific pathogens?
Not per se.. they look for patterns
PAMPs
Pathogen associated molecular patterns
What are some PAMPs? (6)
- unmethylated CpG DNA
- Polysaccharides (cell wall)
- Lipids
- Double-stranded RNA
- Flagella
- Formylated peptides
Does the innate immune system need to differentiate b/w pathogens?
No, just needs to know it is not self
Opsonization
Make a foreign cell more susceptible to phagocytosis
Why is there no advantage in keeping innate cells around?
Innate cells aren’t pathogen-specific
One neutrophil is as good as the next
For innate immunity subsequent infections with the same pathogen result in the ——– response
SAME
no better, no faster
What are the 3 soluble components of innate immunity?
- Anti-microbial peptides and proteins
- Interferon
- Complement
What are the 4 cellular components of innate immunity?
- Phagocytes
- Granulocytes
- NK cells
- Dendritic cells
Response time of the innate? SHorter or faster than adaptive?
Can be immeditate
Can be min and hours
Shorter than adaptive
How does innate immunity recognize targets?
PAMPS
Why is the diversity of innate immunity limited?
Because you are born with it. It is germline encoded
Does innate have memory?
Nope. none
Is the immune response of the innate or adaptive better with an inital exposure?
Innate had a greater immune response to a pathogen on the first exposure
Adaptive immunity is only present in …?
Vertebrates only (has a spine)
What are the two main types of adaptive immunity?
- B-Lymphocytes (antibodies)
2. T-Lymphocytes (cell-mediated cytotoxicity, cytokines)
What happens if the adaptive mistakes self for pathogen?
autoimmunity
What happens if the adaptive mistakes pathogen for self?
immunosuppression
Is target recognition in adaptive immunity specific?
YES very
Which type of immunity requires billions of specific receptors? Why?
Adaptive
for specificity, we need immense diversity
If each receptor had its own indv gene this would overwhelm the genome. What mechanism has the adaptive immunity done to combat this?
The immune system has evolved a mechanism for generating repertoire diversity through the rearrangement of small gene fragments
What does rearranging small gene fragments result in?
limitless diversity
How does the immune system learn if <0.01% of lymphocytes recognize any single pathogen?
In the rare event that one cell finds/recognizes, we tell it to replicate. We amplify the good cell BUT this takes time
What are the 4 steps of clonal selection?
- A single progenitor cells give rise to a large # of lymphocytes, each with a diff specificity
- Removal of self-reactive immature lymphocytes by clonal deletion
- Pool of mature naiive lymphocytes
- Proliferation and differentiation of activated specific lymphocytes to form a clone of effector cells
What is the downfall of clonal selection?
Takes time
BUT it is precise
Is there an advantage to keeping adaptive immunity cells around?
YES, during an immune response some lymphocytes diversify into long-lived memory cells
The advantage is that keeping these cells around means that they are able to specifically recognize a pathogen with high efficiency (preprogrammed)
How long can memory cells last?
Lifetime (basis of vaccines)
What are the soluble components of the adaptive?
Antibodies
What are the cellular components of the adaptive?
B and T Lymphocytes
Response time of the adaptive?
Days
Is the self discrimination of the innate or adaptive better?
Innate is better
Adaptive can have occasional failures such as autoimmunity and immunosuppression
How does the diversity compare b/w the innate and adaptive?
Innate - limited (germline encoded)
Adaptive - unlimited (genetic rearrangement)
Does the adaptive or innate immune respond better to secondary infections?
Adaptive
Faster and better b/c persistent memory
2 ways the adaptive modulate the innate immunity?
- B-Lymphocytes produce highly specific antibodies that bind to target cells
- complement activation
- tagging targets for phagocytosis - Activated T-lymphocytes produce Cytokines (soluble mediators) that modulate the ability of phagocytes to internalize and kill pathogens
How does the innate modulate the adaptive? 2 reasons
- T-lymphocytes need to be activated by the phagocytosis and digestions of the pathogen by cells of the innate immune system
- Lymphocytes also need a second signal for full activation from the innate immune system
