Shared Flashcard Set

Details

Lecture 3
Lecture 3 - Innate Immunity
23
Medical
Professional
08/18/2009

Additional Medical Flashcards

 


 

Cards

Term
PAMPs (pathogen-associated molecular patterns)
Definition
part of innate immunity
located on pathogens
recognized by PRRs (pattern recognition receptors)
combos of sugras, proteins, lipid-bearing molecules and some nucleic acid motifs
Term
what can activate the complement system?
Definition
molecules that recognize PAMPs (innate)
antibodies binding to foreign antigens (adaptive)
Term
activated macrophages secrete?
Definition
IL-1, IL-6 and TNF-alpha; which induce and support inflammatory responses.
Term
What are the steps to neutrophil extravasation?
Definition
1) rolling
2) activation by chemoattractant stimulus
3) arrest and adhesion
4) transendothelial migration
Term
What are human defensins?
Definition
cationic peptides
29-35 aa residues in length
six invariant cysteins that form 2-3 disulfide bonds
kill a wide variety of bacteria:
Stpah aureus
strep pneumoniae
E cloi
Pseudomonas aeruginosa
hemophilus influenzae
Term
what secretes defensins?
Definition
neutrophils
paneth cells (intestines)
epithelial cells (pancrease and kidney)
Term
Name 7 receptors of the innate immune system.
Definition
1)Complement (bloodstream, tissue fluids)
2)Mannose-binding lectin (MBL - bloodstream, tissue fluids)
3) CRP - (bloodstream, tissue fluids)
4) LPS receptor; LPS-binding protein
5) Toll-like receptors (cell surface or internal compartments)
6) NOD family receptors (intracellular)
7) Scavenger receptors (SRs)
Term
What is the target and effect of Complement?
Definition
Target: Microbial cell wall components
Effect: complement activation, opsonization, lysis
Term
What is the target and effect of Mannose-binding lectin (MBL)?
Definition
Target: Mannose-containing microbial CHOs, (cell walls)
Effect: Comoplement activation, opsonization
Term
What is the target and effect of CRP?
Definition
Target: Phosphatidylcholine, pneumococcal polysaccharide (microbial membrane)
Effect: Complement activation, opsonization
Term
What is the target and effect of LPS receptor?
Definition
Target: Bacterial lipopolysaccharide (gram- bacterial cell walls)
effect: delivery to cell membrane
Term
What is the target and effect of Toll-like receptors?
Definition
Target: microbial componenets not found in hosts
Effect: Induces innate responses
Term
What is the target and effect of NOD receptors?
Definition
Target: bacterial cell wall componenets
Effect: induces innate responses
Term
What is the target and effect of Scavenger receptors (SRs)?
Definition
Target: many targets; gram+ and gram- bacteria, apoptotic host cells
effect: induces phagocytosis or endocytosis
Term
What are Toll-like Receptors? (TLRs)
Definition
membrane spanning proteins that share a common structural element in their extracellular region
repeating segments of 24-29aa containing Leucine-Rich Repeats (LRRs)
contain several LRRs, and a subset of LRRs make up the extracellular ligand binding region of the receptor.
Term
What is the intracellular domain of the TLR called?
Definition
TIR - Toll/IL-1 receptor
have 3 regions
Term
What is the ligand for TLR4?
Definition
LPS and F-protein
Term
What is the target microbe for TLR4?
Definition
Gram- bacteria and respiratory syncytial virus (RSV)
Term
What is the function of a neutrophil?
Definition
1) phagocytosis
2) reactive oxygen and nitrogen species
3) antimicrobial peptidese
Term
What is the function of macrophages?
Definition
1) phagocytosis
2) inflammatory mediators
3) antigen presentation
4) reactive oxygen and nitrogen species
5) cytokines
6) complement proteins
Term
What is the function of dendritic cells?
Definition
1) antigen presentation
2) costimulatory signals
3) reactive oxygen species
4) Interferon
5) Cytokines
Term
What is the function of natural killer cells?
Definition
1) lysis of viral-infected cells
2) interferon
3) macrophage activation
Term
What 2 immunoregulatory cytokines do NK cells produce?
Definition
Interferon-gamma
TNF-alpha
these 2 cytokines can stimulate maturation of DCs and coordinate innate and adaptive immunity
Supporting users have an ad free experience!