H 47 Immunologie
The specific binding of immune receptors to foreign molecules is a type of molecular recognition.
Two types of immune defence:
- Innate immunity: in all animals,
- Adaptive immunity: only in vertebrates, activated after immune-response, develops slowly.
47.1 In innate immunity, recognition and response rely on traits common to groups of pathogens
Innate immunity invertebrates
Exoskeleton first line of defence. Chitin also lines the insects intestine, where it blocks infections by
many pathogens ingested with food. Lysozyme: an enzyme that breaks down bacterial cell walls also
protect the digestive system. Immune cells called hemocytes travel through the hemolymph(insects
circularly fluid). Some digest and break down bacteria: phagocytosis. They produce antimicrobial
peptides (short amino acid chains) out of them-> particles travel through body -> changes membrane
structure of fungi and bacteria -> dies. The special macromolecules in the cell membrane work as
identity tags. Innate immune responses are distinct for different classes of pathogens. Toll receptors
recognise lichaamsvreemde delen.
Innitate immunity of vertebrates
Barrier defences
Block entry of many pathogens: skin, mucous membranes lining the digestive, respiratory, urinary
and reproductive tract. Mucous membrane produce mucus. Lysozyme is in mucus and tears and stuff
so it breaks down cell walls. Wallowed -> acidic environment of the stomach -> killed. Skin pH
between 3 and 5.
Cellular innate defences
Toll-like receptor(TLR): binds to particle who is lichaamsvreemd. TLR3: recognise double stranded
RNA, TLR4: recognise lipopolysaccharide(found surface bacteria). TLR5: recognise flagella. Phagocytic
cells:
- Neutrophils: in blood, attracted by signals damage tissue, engulf and destroy
- Macrophages: large, the whole body, clean up group
2 other types of phagocytic cells:
- Dendritic cells: populate tissue with environmental contact, stimulate adaptive immunity,
- Eosinophils: ?
Natural killer cells: through body, detect abnormal surface proteins, release chemicals for cell death.
Antimicrobial Peptides and proteins
Interferons: proteins that provide innate defence by interfering with viral infections. Limit spread,
help control the virus.
Complement system consist of 30 proteins in blood plasma-> inactive -> activates by touching
pathogen -> lysis of cell.
The specific binding of immune receptors to foreign molecules is a type of molecular recognition.
Two types of immune defence:
- Innate immunity: in all animals,
- Adaptive immunity: only in vertebrates, activated after immune-response, develops slowly.
47.1 In innate immunity, recognition and response rely on traits common to groups of pathogens
Innate immunity invertebrates
Exoskeleton first line of defence. Chitin also lines the insects intestine, where it blocks infections by
many pathogens ingested with food. Lysozyme: an enzyme that breaks down bacterial cell walls also
protect the digestive system. Immune cells called hemocytes travel through the hemolymph(insects
circularly fluid). Some digest and break down bacteria: phagocytosis. They produce antimicrobial
peptides (short amino acid chains) out of them-> particles travel through body -> changes membrane
structure of fungi and bacteria -> dies. The special macromolecules in the cell membrane work as
identity tags. Innate immune responses are distinct for different classes of pathogens. Toll receptors
recognise lichaamsvreemde delen.
Innitate immunity of vertebrates
Barrier defences
Block entry of many pathogens: skin, mucous membranes lining the digestive, respiratory, urinary
and reproductive tract. Mucous membrane produce mucus. Lysozyme is in mucus and tears and stuff
so it breaks down cell walls. Wallowed -> acidic environment of the stomach -> killed. Skin pH
between 3 and 5.
Cellular innate defences
Toll-like receptor(TLR): binds to particle who is lichaamsvreemd. TLR3: recognise double stranded
RNA, TLR4: recognise lipopolysaccharide(found surface bacteria). TLR5: recognise flagella. Phagocytic
cells:
- Neutrophils: in blood, attracted by signals damage tissue, engulf and destroy
- Macrophages: large, the whole body, clean up group
2 other types of phagocytic cells:
- Dendritic cells: populate tissue with environmental contact, stimulate adaptive immunity,
- Eosinophils: ?
Natural killer cells: through body, detect abnormal surface proteins, release chemicals for cell death.
Antimicrobial Peptides and proteins
Interferons: proteins that provide innate defence by interfering with viral infections. Limit spread,
help control the virus.
Complement system consist of 30 proteins in blood plasma-> inactive -> activates by touching
pathogen -> lysis of cell.
