Review of Innate System Flashcards
Why do we need an innate immune response when a adaptive immune response is present?
Adaptive response is too slow to protect against new pathogens (new microbe replication fast and peaks quickly and adaptive immune system only comes after this peak) - for survival until adaptive immune response comes in
How specific is adaptive immunity?
Very specific recognition of infectious agent through protein/antigen
How specific is innate immunuty?
No specific antigen recognition
What part of pathogens are recognised by innate immunity
- recognises broadly conserved feautures on pathogens - PAMPs (pathogen associated molecular patterns)
What are PAMPs? + what is their purpose
Molecules present only on pathogens not on host cells so recognised as non self - found on all pathogens (diff types) - needed for pathogen survival
What type of bacteria are PAMPs found on?
gram positive and negative
What is the PAMP on gram negative bacteria?
lipopolysaccharides found in outer membrane
What is the PAMP on gram positive bacteria?
TETICHOIC ACID, peptidoglycan, lipoteichoic acid in outer membrane
Give examples of general PAMPs? in diff types of pathogen
Bacterial flagella
Abnormal protein glycosylation
Abnormal nucleic acids - viruses
What part of host recongises PAMPs?
PRR (pattern recognition receptor)
Why are viruses PAMPs nucleic acid?
Dont have cell wall to recongise things on surface of the pathogen
What does germ line encoded mean? + example of something that is germ line encoded
receptors that Cannot be rearranged somatically - PRRs
What are the classes of PRRs? and what does each do
Intracellular - (cytoplasmic) recognise PAMPs inside a cell - pathogen has already entered cell
Extracellular - recognise PAMPs outside cell - before pathogen enters cell
Secreted - tag circulating pathogens for elimination
How can you experiment mice reaction to see what would happen if they dont have innate response
Get rid of PRRs so no receptors to recognise PAMPs (general recongition in innate immunirt)
What are all the component of innate immunity?
Inflammatory response Phagocytes Complement Cytokines, chemokines, and anti-microbial peptides (AMPs) Natural killer cells
Name a few phagocytes?
Monocytes, NEUTROPHILS, dendritic cells
What is the purpose of an inflammatory response?
Generic defense mechanism to localise and eliminate injurious agents/damaged tissue components + prevent pathogen from leaving site of infection
What triggers inflammatory responses?
Pro-inflammatory cytokines and chemokines at the site of infeciton
What are the other effects of an inflammatory response?
Enhanced permeability and extravasation
Neutrophil recruitment
Enhanced cell adhesion
Enhance clotting
What is extravasation?
Cells can pass from blood to tissues
Why is it good to enhance cell adhesion in inflammatory response?
Neutrophils and macrophages stick to tissue at site of infection
Why is increased clotting important in inflammatory response?
Identifying restriction and restrict - cut off blood supply
Which components of innate immunity is linked to eachother?
Phagocytes, complement and cytokines, chemokines + AMPs
What is important about cell recongition in phagocytosis?
Need to know which cells are infected to produce correct cytokines and chemokines and not destroy healthy cells