3. Innate Immune System Flashcards
What sort of pathogen is poorly affected by inflammation?
Intracellular pathogens
What is the downside to inflammation?
It can lead to substantial tissue damage and disease
What is a function of the innate immune system that has nothing to do with bacteria?
Initiation of the process of tissue repair
What might cause pain at the site of inflammation?
Inflammatory mediators released by immune cells stimulate the nerves.
What is the function of type 1 (non-immune) interferon?
Blocks viral replication within host cels
What do cells of the innate immune system chiefly recognize?
Pathogen associated molecular patterns
What are pathogen associated molecular patterns (PAMPs) unique to?
A given class of microbes
Innate immune cells recognize pathogens, so why is it we say they’re less specific than adaptive cells?
Since innate cells recognize PAMPs rather than unique antigens, so they are said to be less specific.
What are the four criteria for a pathogen associated molecular pattern to be recognized by our innate immune system?
- Effective indicator of pathogen
- Unique to a class of pathogen
- PAMP cannot be easily supressed or hidden by the pathogen (vital to life)
- No structural similarity to self antigens
What are the primary PAMPs for:
Gram Negative Bacteria
Lipopolysaccaride
Porin
Lipoproteins
What are the primary PAMPs for:
Gram Positive bacteria
Peptidoglycan
Lipoteichoic acid
Teichoic acid
What is the primary PAMP for:
Mycobacteria
Lipoarabinomannan
What is the primary PAMP for:
Fungi
Manno-proteins
What are two important locations for toll like receptors in the cell?
On the cell surface and on the inside of endosomes
What do endosomal TLRs respond to?
Nucleic acids only
Which four TLRs recognize intracellular pathogens?
TLR 3,
TLR 7,
TLR 8,
TLR 9
Why do mannose PRRs not respond to the mannose in our bodies?
Because they respond to glycans with terminal mannose only, which does not occur in humans.
For the TLR1:TLR2 heterodimer:
What ligands are recognized?
What cells carry the receptor?
Lipopeptides and GPI
Monocytes, dendritic cells, eosinophils, basophils, mast cells
For the TLR2:TLR6 heterodimer:
What ligands are recognized?
What cells carry the receptor?
Lipoteichoic acid and Zymosan
Monocytes, dendritic cells, eosinophils, basophils, mast cells
For TLR3
What ligands are recognized?
What cells carry the receptor?
Double stranded viral RNA
NK Cells
For the TLR4:TLR4 homodimer:
What ligands are recognized?
What cells carry the receptor?
Lipopolysaccaride
Macrophages, dendritic cells, mast cells, eosinophils
(not basophils)
For TLR5
What ligands are recognized?
What cells carry the receptor?
Flagellin
Intestinal epithelial cells
For TLR7
What ligands are recognized?
What cells carry the receptor?
Single stranded viral RNAs
Plasmacytoid dendritic cells, NK cells, eosinophils, B Cells
For TLR8
What ligands are recognized?
What cells carry the receptor?
Single stranded viral RNA
NK cells