Lecture 4 Flashcards
What is innate immunity?
the initial host defense response to pathogens that prevents, controls, or eliminates infection
Neutrophil function
early phagocytosis and killing of microbes
macrophage function
efficient phagocytosis and killing of microbes, secretion of cytokines that stimulate inflammation
NK cells function
lysis of infected cells, activation of macrophages
Function of complement
killing of microbes, opsonization of microbes, activation of leukocytes
mannose-binding lectin (collectin) function
opsonization of microbes, activation of complement (lectin pathway)
C-reactive protein (pentraxin) function
opsonization of microbes, activation of complement
THF, IL-1, chemokines function
inflammation
IFN-a, B function
resistance to viral infection
IFN-y function
macrophage activation
IL-12 function
IFN-y production by NK cells and T cells
IL-15 function
proliferation of NK cells
IL-10, TGF-B function
control of inflammation
what is a PAMP?
pathogen-associated molecular pattern
Cell receptors that recognize PAMPs are called what?
pattern recognition receptors (PRRs)
Why do phagocytes use PRRs?
to distinguish self from non self
What do toll like receptors (TLRs) do?
recognize pathogens and activate inflammation
where are TLRs expressed?
on immune cells, including monocytes, neutrophils, macrophages, and dendritic cells
What are nucleotide oligomerization domain (NOD) like receptors (NLRs)
a specialized group of intracellular proteins that play a critical role in the regulation of the los innate immune response
What is the function of NLRs?
act as a scaffolding protein that assemble signaling platforms that trigger NF-KB and mitogen activated protein kinase (MAPK) signaling pathways
NLRs contort the activation of inflammatory _____
caspases
What is necrosis?
passive, catabolic cell death in response to external toxic factors
Inflammation is an innate reaction caused by what?
- increased blood supply to area–redness and heat
- increased capillary permeability– leak from blood vessels–swelling and pain
- massive influx of neutrophils
- arrival of monocytes/macrophages
- distortion of the homeostasis and loss of function
What are defensins?
small cationic peptides that contain both cationic and hydrophobic regions
What produces defensins?
epithelial cells of mucosal surfaces and granule containing leukocytes including neutrophils, NK cells and CTLs
What are cathelicidins?
direct toxicity to microorganisms and the activation of leukocytes
What are the functions of NK (natural killer) cells?
- recognize ligands on infected cells or cells undergoing other types of stress
- kill those infected or stressed cells
- eliminate reservoirs of infection and thus release intracellular pathogens for phagocytosis
