Innate Immunity - Hunter Flashcards
Describe colonization vs. infection:
Colonization is like having bacteria in your nose but not causing any problems; infection is when bacteria have broken your immune defenses and cause symptoms
Describe infection vs. disease:
Infection is when bacteria have made it into your body, while disease in when your cells have been damaged AS A RESULT of the infection.
What are opportunistic pathogens?
Pathogens that are on your body but only cause disease when you are immunosuppresed
What are the intrinsic epithelial barriers to infection?
Mechanical, chemical, and microbiological
Describe the mechanical intrinsic defenses of the skin?
epi cells joined by tight junctions
longitudinal flow of air or fluid
Describe the chemical defenses of the skin?
- fatty acids
- B-defensins (anti-microbial peptide)
- Lamellar bodies (seals the skin)
- cathelicidin (anti-microbial in lysosomes)
Describe the mechanical barriers of the gut?
- epi cells joined by tight junctions
2. longitudinal flow of liquid
Describe the chemical barriers of the gut?
- low pH
- enzymes (pepsin)
- alpha-defensins (cryptdins)
- RegIII (lecticidins)
- Cathelicidin
Describe the mechanical defenses of the lungs?
- epi tight junctions
2. Movement of mucus by cilia
Describe the chemical defenses of the lung?
- Pulmonary surfactant
- Alpha-defensins
- cathelicidin
Describe the mechanical defenses of the ENT cavities?
- epi tight junctions
- tears (physically wash away shit)
- nasal cilia
Describe the chemical defenses of the ENT cavities?
- enzymes in tears and saliva (lysozyme)
- Histatins (antimicrobial/antifungal)
- B-defensins
What are the three mechanisms of direct tissue damage by pathogens?
- Exotoxin
- Endotoxin
- direct cytopathic effects
Microbial pathogenesis involves (direct/indirect) damage of tissues
direct
Immunopathology involves (direct/indirect) damage to tissues
indirect
What are the three methods of tissue damage via immunopathology?
- Immune complexes
- Anti-host anitbody
- Cell-mediated immunity
What are the three antimicrobial ENZYMES?
- Lysozyme (tears)
- Pepsin (gut)
- Secretory phospholipase A2
How do defensins function?
Embeds itself in the bacterial membrane, dimerizes, and opens a pore
Defensins, cathelicidins, and histatins can all function because they have what kind of charge?
amphipathic
t/F: anti-microbial peptides are normally produced as pro-peptides
T
What cell type initiates inflammation once pathogens breach the epithelium?
macrophages
what two classes of chemicals do macrophages release to initiate the inflammation cascade?
chemokines and cytokines
(blanks) like TNF-a, cause vasodilation, increased vascular permeability, and upregulate expression of adhesion molecules to epithelium
cytokines
Chemokines attract what types of cells?
neutrophils (via CXCL8) and monocytes
Phagocytic cells, plasma cells, and the complement system engage and eliminate pathogens (before/during) the adaptive response is generated
BEFORE
Activation of what two systems during inflammation causes pain and blood clotting?
Kinin and coagulation
If the innate system works, is there a need for inflammation?
Nope
Macrophages recognize pathogens by (blank) encoded receptors
genome
What are the first two lines of defense if bacteria overrun tissue?
macrophages and complement system
T/F: neutrophils are more phagocytic than macrophages
true
What is on top of the PM in gram positive bacteria?
PDG layer with lipteichoic anchors and surface proteins
what is on top of the Pm in gram negative bacteria?
small PDG layer, then lipoprotein layer, then LPS layer
Do we want macrophages to recognize specific pathogens or patterns?
patterns
What are the four PAMPs for bacteria?
- f-Met-Leu-Phe receptor
- Mannose receptor
- Scavenger receptor
- LPS binding protein, TLR-4, and CD14
what are the two PAMPs for fungi?
Mannose recetpros and Dectin-1-glucan receptor. (if you leave sugary stuff out you will get mold)
What is the PAMP for viruses
Mannose
What is the scavenger receptor?
acetylated lipoproteins
LPS binding protein, TLR-4 and CD14 receptors are for gram (blank) bacteria
negative
How many human TLR genes are there?
10
TLR proteins are (blank) receptors
PAMP
T/F: TLR can be on the cell surface or endosomal
True
TLR activation engages transcription factor (blank) and induces production of inflammatory mediators
NF-Kb
Nucleoside Oligomerization Domain (NOD)-like proteins are similar to (blank) proteins
TLR
What do NODs do?
detect cytoplasmic bacteria and signal inflammation
What do retinoic acid inducible Gene (RIG) like proteins do?
detect viral RNA in the cytoplasm and signal inflammation
Are TLRs highly conserved?
yes
What is another name for LPS?
endotoxin
If pathogens invade the cytoplasm, (blanks) kick in and take over the job of TLRs
NODs
Where are RIGs located?
in the cytoplasm
What is the general cascade of PAMP producing danger signals?
- PAMP recognition
- TLR dimerization
- Intracellular signaling
- Gene expression
What protein is recruited by dimerized TLRs?
IRAK4 and IRAK1
How is NF-Kb produced?
IRAK4 mediated scaffolding releases TAK1 which leads to degradation of IkB and release of NF-Kb
IRAK-1 deficiency is a rare autosomal (blank) disease
recessive
How do you diagnose IRAK1 deficiency?
clinical suspicion and demonstation of poor response of monocytes to TLR agonists
What happens if you have no IRAK4?
No immune response via no inflammatory response via no cytokine release
A functioning inflammatory resposne is critical in host defense against (blank) bacterial infections, as evidenced in IRAK1 deficiency
pyogenic
What are the two major categories of defects in neutrophil function?
Defects in intracellular killing and adhesion defects
CGD, Chediak Higashi, and Type I integrin deficiency are all (blank)
defects in neutrophil function
CGD and G6PD deficiency are types of (blank)
abnormal respiratory burst
MPO deficiency, specific granule deficiency, and Chediak-Higashi are types of (blank)
granule abnormalities