imm 1 Flashcards
What are some vital things pathogens need to be able to survive in our body?
Lots of nutrients Correct temperature and PH Water
What does our immune system provide protection from?
Pathogens and parasites
Give some examples of pathogens
- Bacteria
- Viruses
- Fungi
Give some oral diseases that are caused by bacteria
Congenital syphallis
Periodontal disease
Hutchinsons incisors
Give some oral diseases that are caused by viruses
Primary herpetic gingiostomatitis| Kaposi’s sarcoma (HIV)
Give some oral diseases that are caused by fungi
Oral thrush= fungal candida
Vertebrate immune defences has how many immune layers
3 layers:1. Physical and biochemical barriers 2. Innate immune system 3. Adaptive immune system
Describe the physical barriers we have to disease
They are provided by our epithelial layers like skin and mucosal layers
What initiated the adaptive immune system?
The innate system
What are the 2 types of physical defences
Strong external barriers| More vulnerable mucosal membranes
Give examples of strong external barriers
- Skin2. Nails 3. Hair
Give examples of more vulnerable mucosal membranes
- Oral mucosa 2. Sinuses 3. Respiratory tract 4. Kidneys 5. Bladder6. Intenstines7. Eyes and oral cavity 8. Gastrointestinal tract
What type of barriers do surface epithelia provide to infection?
Provides
1. mechanical
2. chemical
3. microbiological barriers to infection
What type of mechanical barrier does the skin provide in response to infection?
- Have epithelial cells joined by tight junctions| 2. Longitudinal flow of air or fluid
What type of chemical barrier does the skin provide in response to infection?
- The epithelial cells produce fatty acid| 2. They also produce beta defensives lamellar bodies and cathelicidin
What type of mechanical barrier does the gut provide in response to infection?
- Have epithelial cells joined by tight junctions| 2. Longitudinal flow of air or fluid
What type of chemical barrier does the gut provide in response to infection?
- Has a low pH2. Produces enzymes like pepsin 3. Produce alpha defensins (cryptdins), reg III and cathelicidin
What type of mechanical barrier do the lungs provide in response to infection?
- Have epithelial cells joined by tight junctions| 2. Have cilia that move mucosa
What type of chemical barrier do the lungs provide in response to infection?
- Pulmonary surfactant| 2. Produce alpha defensins and cathelicidin
What type of mechanical barrier do the eyes nose and oral cavity provide in response to infection?
- Have epithelial cells joined by tight junctions 2. They eyes produce tears3. Nasal cilia
What type of chemical barrier do the eyes nose and oral cavity provide in response to infection?
- Enzymes in tears and saliva- lysozyme| 2. Produce histatins and beta defensins
What type of enzyme is lysozyme?
glycosidase enzymes
What is lysozyme most active against?
Gram positive bacteria
Give examples of some gram positive bacteria
Streptococcus mutans (cariogenic).
Why is lysozyme more active against gram positive bacteria?
As it is easier to get to heir peptidoglycan layer
What does lysozyme cleave?
The bonds between different types of sugars| It digest peptidoglycan
What does the activity of lysozyme end up exposing?
A portion of the lipid bilayer in the bacterial cell membrane
What is the exposed portion of bacterial lipid bilayer vulnerable to?
Invasion from other molecules like antimicrobial peptides
What are antimicrobial peptides synthesised as?
As inactive proform
What is a zymogen?
An inactive form of an enzyme usually needs proteolytic cut to become active
What are the 3 types of antimicrobial peptides present in humans?
- Defensins2. Cathelicidins3. Histatins
Describe defensins
- They are amphipathic| 2. They are insertion in membranes that generate pores causing membranes to become leaky killing the bacterial cell
What are the different types of defensins we may have?
Alpha defensins produces by specialised innate immune cells| Beta defensins produced by epithelial cells
Describe Cathelicidins
- It’s amphipathic2. It causes membrane disruption3. Has immuno-regulatory properties
What type of cathelicidins do humans possess?
LL-37 ONLY
What are Histatins produced by?
The parotid, sublingual and submandibular glands