lect 11.2 Flashcards
what do DC recognizing PAMPs lead to
activation of phagocytosis
DC migrate of lumph noes carrying intact or degraded pathogens and bind them to MHC to be recognized by T cells so they can be activated
phagocytosis
engulfment and internalization of materials such as microbes for their clearance and destruction
what are the steps for phagoxytosis
- bact binds on PRRs on membrane invaginatinoss called pseudopodia
- bact ingester and forms a phagosome
- phagosome fuses with lysosome
- bact is killled and digested by low PH actiavted lysossomal enzymes
- digestion products released from ecll
what cells do phagocytosis
macrophages
neutrophils
immature dendritic cells
macrophages examples
kuppfer cells- liver
microglial cells- CNS
alveolar macrophages- lung
perioneal macrophages- peritoneal fluid
what are langerhan celsl
immature dc capable of doing phagocytosis in the skin and mucosa
how are microbes recognized
directly via the PRR: PAMP interaction
phagocytes recognize soluble proteins bound to microbes thorugh opsonin receptors in a process called opsonization
what are the types of soluble factors
interferons
cytokines
complement
what are interferons
protiens (cytokines) produced by virus infected cells that induce antiviral response in neighbouring
what produces interferons cytokines
virus infected cells
what do interferons induce
antiviral response in neighbouring cells
what are cytokine exampes
ILs 1 + 6, TNF a
what do cytokines do
induce and support inflamatory responses
what is complement
a group of proteins that are produced in the liver and are found in the blood and lymph
what does complement do
recognizes PAMPs and kils pathogens by lysis or opsonization
where are complenet protiens synth
in the liver
what is the IFN system
phase 1 and 2
phase 1 detectino leads to production of IFN a/B promoter
phase 2- activation of IFN regulated anti viral genes
what causes induced cellular innate responses
type I interferons which have potent antiviral effects
how are dead/ dying cells cleared
macrophages clear apoptotic or necrotic cells via recognition of DAMPs
what inhibits phagocytosis by macrophages
cd47- healthy cells express this
what are DAMPs
eat me signals - PS, LPC
what does tissue damage and bacteria cause
resident sentinel cells to release chemoatttractants and vasocative factors to inc blood flow and permeablity
this lead to influx of fluid and cells
neutrophils and macrohpages migrate to site of infection due to chemotaxis
phacocytes and antibacterial substanes destroy bacteria
characteristics of inlamation
Characteristics of
Inflammation
* Heat
* Redness
* Swelling
* Pain
* Loss of function`
what acts as a bridge between innate and adaptive systems
dendritic cells
bring Ag from site of infection for T cell presentation and activation in lymph nodes so they can differentiate into pathogen specfiic subsets for Ag clearance
