Innate immune system part B
Pathogen recognition
Innate IS
Adaptive IS
Molecular patterns
Learns 'self'
Everything else is target
Pathogen-associated microbial patterns
Targets recognised on pathogens
Avoid damage to self
Discriminate between self and non-self
Pathogen recognition receptors
Used by pathogens
Detect PAMPs
Receptor
Opsonisation intermediate
Toll-like receptor
Soluble factors
C-reactive protein
"Red flag" saying its foreign
Detect foreign
Toll-like receptors
Location
Lymphocytes
Neutrophils
Basophils
Macrophages
Dendritic cells
TLR-PAMP
Secretion of cytokines
Messengers
Activate innate and adaptive IS
Identify foreignness
Complement system
C1-C9
Enhances antibodies/phagocytes
Directly kill too
Different pathways
Classical
Antibody-antigen
Alternative
Bacterial cell wall
Acute phase proteins/Lectin
Components
Activation of C3
C3b
Phagocytosis (opsinisation)
C3a/C5a
Mast cell degranulation
Cytokines
C5b
Site of C3b/C5b attachment
Channels across membrane
Lysis
Alarm mediators
Recognise PAMPs
C-reactive protein and mannose binding lectin
Recruit complement
Cytokines
Secreted by:
Lymphocytes
Antigen presenting cells
Fibroblasts
Endothelial cells
Monocytes
Hepatocytes
Kidney cells
Interleukins
Functions
Cell growth/differentiation
Progenitor blood cells
Regulates immune cell activity
Hypersensitivity and inflammation
Interferons
Interfere with viral replication
Alpha, beta, gamma
Protect uninfected cells
Induced by tumours
Early defence
Phagocytosis killing mechanisms
Oxidative
Non-oxidative
Reactive oxygen intermediates
Lysosomes
Cathepsin G
Damages microbial surface
Defensins
Produces channel in membrane
Cationic proteins
Bactericidal
Lactoferrin
Binds iron
Lysozyme
Digests cell wall
Nitric oxide