Lecture 7: Innate immunity Flashcards
1
Q
First line of defence:
A
Behavioural, societal, cultural
2
Q
First lines of INDIVIDUALS defence?
A
skin and membranes
3
Q
some epithelia are good barriers:
A
- hairy skin
- tight junctions
4
Q
chemical individual defences
A
- Sweat, lactic acid, sebum, lysozymes
- Stomach pH
5
Q
Defensins
A
- +ve peptides (15-20 residues)
- Broad spectrum
- -Microbes, viruses and parasites
- Target membrane
6
Q
some epithelia are risky
A
-moist membranes: eye respiratory system GI system GU system (conjunctivitis, TB, syphilis)
7
Q
Key players in immunity:
A
- The lymphatic and cardiovascular systems / cells (and others)
- Effector and signaling molecules
8
Q
innate immunity:
A
- Physical barriers
- Phagocytes
- Immunological surveillance
- -Natural killer cells
- Interferons
- Complement
- Inflammation
9
Q
pathogen recognition: no ‘recognition’
A
e.g. stomach acids, defensins
10
Q
pathogen recognition: General recognition
A
pathogen-associated immunostimluants
- F-met- prokaryote proteins
- Lipopolyscaccharid (LPS)
- Foreing nucleic acids
11
Q
pathogen recognition: Pattern-recognition receptors (PRRs)
A
- soluble (e.g. compliment system)
- Membrane-bound (e.g. toll-like receptors)
12
Q
collectins:
A
- Soluble plasma components (+ surfactant)
- Bind to specific carbohydrates
- Bind to phagocytes
- Or (mannan-binding lectin) interact with complement
13
Q
complement system
A
- 20+ soluble proteins, some are enzymes, PRR’s
- bring lysis, phagocytosis, inflammation
14
Q
toll-like receptors:
A
- Macrophages, neutrophils, epithelia
- Bind range of pathogen proteins, inc. LPS
- Promote inflammation
15
Q
interferons secreted by:
A
- Lymphocytes, macrophages etc
- Virus - infected cells
Secretion evoked by e.g. 2x stranded RNA
