Lecture 6: Innate vs Adaptive immunity Flashcards
What does the immune response via time plot look like for innate immunity
Big hump than slows, doesn’t clear the infection
List 5 components of innate immunity (overview)
- barriers
- anti-microbial peptides
- complement
- soluble mediators
- phagocytes, granulocytes
Where and what are anti-microbial peptides and proteins and what do they do
- often present in secretions (sweat, mucus tears)
- positive charged amino acids
- target lysis
Describe complement
- proteins that you attach to a target cell
- activate proteolytic cascade
What cells are soluble mediators
- interferon’s
- cytokines and chemokines
What does interferon do
- induce general anti-viral state
- induce fever
What do cytokines and chemokines do
- increase production of white blood cells
- recruit cells to a site of infection
What are phagocytes and granulocytes
- found throughout the body
- identical
- often directly kill target
- play a role in the activation of the adaptive immune response
Do barriers do target recognition
No they keep everything out
What systems of the innate immune system do target recognition
-antimicrobial peptides
-complement
-soluble mediators
-phagocytes and granulocytes
They differentiate between self and non self
What is target recognition
When molecules recognize molecular patterns associated with various classes of pathogens
What are PAMPs
Pathogen associated molecular patterns they are what our bodies molecules recognize on pathogens
What else can the innate immune system recognize besides PAMPs
Targets tagged with soluble components of the innate immune system
What is opsonization
A pathogen is tagged by antibodys and ingested by a macrophage
Do innate cells generally maintain memory of certain pathogens
No, they usually die following the immune response
Does the innate immune system form memory cells
No
Why is there no advantage of keep innate cells around
Identical one does not have more protectively than others
What does the inmates lack of memory mean for its response
No faster or better, doesn’t adapt
What organisms have adaptive immune systems
Vertebrates only
What does adaptive immunity do during the course of an infection
Evolves
What two types of lymphocytes are in adaptive immunity
B-lymphocytes and T-lymphocytes
What is a B-lymphocyte
Antibodies
What are T lymphocytes
-cell mediated cytotoxicity
-cytokines
(Being toxic to cells)
What is cell mediated immunity
Immunity not involving antibodies
What happens if the adaptive immunity mistakes self for pathogen
Autoimmunity
What happens if adaptive immunity mistakes pathogen for self
Immunosuppression
What is lymphocyte specificity
- recognizes individual pathogens
- able to differentiate between two similar pathogens
- recognize specific protein/lipid/sugar residues on targets
- able to target specific cells without damaging neighbouring cells
Because lymphocytes are able to specifically recognize billions of different molecules they need billions of receptors how is this combatted?
The rearrangement of small gene fragments results in limitless diversity
Due to nearly limitless random receptor generation what sometimes happens
Cells can express receptors that recognize “self” these must be eliminated to prevent autoimmunity
How do you get lymphocytes recognizing pathogens
Select a cells that recognizes the pathogen and start cell proliferation
According to the clonal selection theory how many receptors does each lymphocytes have
Each lymphocyte has a single type of receptor with unique specificity
What action causes lymphocyte activation
Interaction between a pathogen and a lymphocyte receptor capable of binding that molecule with high affinity
The differentiated effector cells derived from an activated lymphocyte are what to the parental cell
They will bear receptors of identical specificity
What happens to lymphocytes bearing receptors specific for self molecules
They are deleted at an early stage of lymphoid cell development
How do memory cells arise
During an immune response some lymphocytes diversify into memory cells
What do these memory cells help with in regards to the adaptive immune system
Subsequent responses to the same pathogen are more rapid and of a greater magnitude
