Innate Immunity Flashcards
What are the external barriers?
- epithelial barriers
- antimicrobial proteins/peptides
What are the types of antimicrobial proteins/peptides?
- lysozyme
- defensins
- surfactants
Where are lysozymes found?
saliva
What do lysozymes do?
kills microbes
What are defensins secreted by?
epithelial cells
What do defensins do?
- kill bacteria
- alter lipoprotein envelope around viruses
What are surfactants secreted in?
respiratory tract
What do surfactants do?
bind to microbial surfaces and alter surface proteins
Where are PRRs found?
on all cells of immune system
What do PRRs do?
bind to PAMPs on pathogen
What are some PRRs expressed on?
cell membranes or within cell
What does PRRs expressing on cell membrane allow for?
recognition of extracellular pathogens
What does PRRs expressing within cells allow for?
recognition of intracellular pathogens
What does PRR signaling induce (aka PRR binding to PAMPs)?
induces expression of different proteins
What proteins are induced by PRR signalling?
- antimicrobial proteins
- Type I interferons
- proinflammatory cytokines
- chemokines
- enzymes
What antimicrobial proteins are expressed by induction of PRR signaling?
- defensins
- cathelicidin
What do defensins do?
kill microbes
What do cathelicidins do?
work similarly to defensins, kill microbes
What are the Type I interferons are expressed by induction of PRR signaling?
IFN alpha and IFN beta
What do IFN alpha and IFN beta do?
- increase expression of MHC - 1 on cells
- inhibition of viral replication within cells
What proinflammatory cytokines are expressed by induction of PRR signaling?
IL - 1, IL - 2, TNF - alpha
What do IL- 1, IL-6, and TNF alpha do?
increase vascular permeability
What do chemokines do?
recruit cells to certain tissues
What chemokines are expressed by induction of PRR signaling?
IL-8
What does IL- 8?
recruits neutrophils to site of infection
- what causes visible inflammation
What enzymes are express by induction of PRR signaling?
- inducible nitric oxide synthase (iNOS)
- cyclooxygenase 2 (COX 2)
What do enzymes do?
generate antimicrobial/proinflammatory mediators
What does inducible nitric oxide synthase do?
produces nitric oxide (NO) which damages pathogen membranes
What does cyclooxygenase 2 do?
produces prostaglandins which mediate inflammatory response
