Module: Infection and Immunity BIOS5050
Date: Friday 19th January
Time: 1pm-2pm
Immunology: Innate Immunity
Innate immunity is a defence system were born with, this encompasses macrophages, and
dendritic cells. It is found in all animals, including plants. Any eukaryotic cell has innate
immunity. It encompasses exterior defences, including chemicals, physical barriers, and cells.
Learning Objectives:
To understand the exterior defences.
The microbiome in protecting the GI tract from pathogen attack.
Defensins (evolutionary chemical that help fight pathogens)
3 phases of the immune response
How is inflammation defined?
Phagocytosis, how we engulf and digest bacteria using macrophages and dendritic
cells.
Which pathogenic bacteria have strategies to escape bacteria?
Key terms:
PAMPs – pathogen associated molecular patterns.
PRR’s – pathogen recognition receptors
Commensals – embryotic bacteria, we have up to 10-11 individual commensals living in our
gut.
Continual evolution, finding new strategies for bacteria to avoid the immune system.
Exterior and physical defence systems:
1. Enzymes (lysozyme) in our tears - These chew through the layer of the peptidoglycan
chain to create a path and expose the lipid bilayer.
2. Fatty acids in our skin protecting us from infection.
3. Low PH in vagina
4. PH2 in the gut
5. Rapid air movement in the respiratory tract.
6. Flushing of the urinary tract – this is important to remove toxins from the bladder.
7. Air movement to stop bacteria build up in the airways. Unless you are a smoker, as
the cilia become paralysed by the smoke.
Gram positive bacteria – have a thicker cell wall and take up the dye during tests in
microbiology labs.
Gram negative bacteria – have a smaller cell wall and do not retain the dye.
Table showing the barriers that prevent pathogens getting in.
Skin – fatty acids, beta defences, proteins, microbiome (control uptake of pathogens).
Gut – low PH in stomach, pepsin breaks down the proteins.
1
Date: Friday 19th January
Time: 1pm-2pm
Immunology: Innate Immunity
Innate immunity is a defence system were born with, this encompasses macrophages, and
dendritic cells. It is found in all animals, including plants. Any eukaryotic cell has innate
immunity. It encompasses exterior defences, including chemicals, physical barriers, and cells.
Learning Objectives:
To understand the exterior defences.
The microbiome in protecting the GI tract from pathogen attack.
Defensins (evolutionary chemical that help fight pathogens)
3 phases of the immune response
How is inflammation defined?
Phagocytosis, how we engulf and digest bacteria using macrophages and dendritic
cells.
Which pathogenic bacteria have strategies to escape bacteria?
Key terms:
PAMPs – pathogen associated molecular patterns.
PRR’s – pathogen recognition receptors
Commensals – embryotic bacteria, we have up to 10-11 individual commensals living in our
gut.
Continual evolution, finding new strategies for bacteria to avoid the immune system.
Exterior and physical defence systems:
1. Enzymes (lysozyme) in our tears - These chew through the layer of the peptidoglycan
chain to create a path and expose the lipid bilayer.
2. Fatty acids in our skin protecting us from infection.
3. Low PH in vagina
4. PH2 in the gut
5. Rapid air movement in the respiratory tract.
6. Flushing of the urinary tract – this is important to remove toxins from the bladder.
7. Air movement to stop bacteria build up in the airways. Unless you are a smoker, as
the cilia become paralysed by the smoke.
Gram positive bacteria – have a thicker cell wall and take up the dye during tests in
microbiology labs.
Gram negative bacteria – have a smaller cell wall and do not retain the dye.
Table showing the barriers that prevent pathogens getting in.
Skin – fatty acids, beta defences, proteins, microbiome (control uptake of pathogens).
Gut – low PH in stomach, pepsin breaks down the proteins.
1
