Imunology

Question 1

Symptoms of inflammation?

Answer 1

Pain
Redness
Heat
Swelling

Question 2

What is dolor?

Answer 2

Pain

Question 3

What is rubor?

Answer 3

Redness

Question 4

What is calor?

Answer 4

Heat

Question 5

What is turgor?

Answer 5

Swelling

Question 6

Process of inflammation?

Answer 6

1) bacteria trigger macrophages to release cytokines and chemokines
2) cytokines cause vascular dilation and permeability
3) leukocytes move to periphery of blood vessel due to increased expression of adhesion molecules by endothelium
4) inflammatory cells extravasate at site of infection and release inflammatory mediators
5) blood clotting occurs at microvessels

Question 7

What causes dilation of blood vessels in inflammation?

Answer 7

Cytokines

Question 8

Why do leukocytes move the the periphery of blood vessels during inflammation?

Answer 8

Increased expression of adhesion molecules by endothelium

Question 9

What causes redness, heat and swelling in inflammation?

Answer 9

Vasodilation and increased vascular permeability

Question 10

What causes pain during inflammation?

Answer 10

Inflammatory cells extravasate into tissue and release inflammatory mediators

Question 11

Common causes of chronic inflammation?

Answer 11

Pathogens
Tumours
Autoimmunity
Atherosclerosis
Heart disease
Obesity

Question 12

Two kinds of IBD?

Answer 12

Ulcerative colitis
Crohn’s disease

Question 13

What immune reaction causes IBD?

Answer 13

Immune reaction to commensal bacteria of the gut

Question 14

What is rheumatoid arthritis?

Answer 14

Chronic inflammation of the joints causes by autoimmunity

Question 15

What do antibodies react to in rheumatoid arthritis?

Answer 15

Fc regions of IgG

Question 16

What type of hypersensitivity reaction is rheumatoid arthritis?

Answer 16

III

Question 17

What is the microbiota?

Answer 17

The symbiotic microbial cells mainly found in the gut

Question 18

How many bacterial species in the gut?

Answer 18

100-1000

Question 19

What is the microbiome?

Answer 19

The collective genes of the microbiota

Question 20

What age does the microbiome become established?

Answer 20

Around 2 years old

Question 21

Can the microbiome change?

Answer 21

Subtle changes can happen depending on life circumstances

Question 22

Examples of bacteria in GI biofilm?

Answer 22

Peptostreptococcus
Clostridium
Bacteroidetes
E. Coli
Lactobacillus
Bifidobacterium
Klebsiella
Proteus
Enterococcus

Question 23

What can influence the microbiota?

Answer 23

Illness
Antibiotics
Chemo
Diet
Mode of delivery

Question 24

How does mode of delivery affect the microbiota?

Answer 24

Faecal microbiota of 72% vaginally delivered babies resembled their mothers
In C-section it was reduced to 41%

Question 25

Benefits of GI microbiota?

Answer 25

Produce enzymes that aid in breakdown of dietary compounds or compounds from the liver and allow reabsorption
Lactic acid bacteria produce vitamin B12
Produce bacteriocins that kill other bacteria
Bacterial competition to inhibit growth of pathogenic bacteria

Question 26

Two modes of bacterial competition?

Answer 26

Interference competition
Exploitative competition

Question 27

What is interference competition?

Answer 27

Invokes antagonistic factors produced to impede competitors
E.g. bacteriocins

Question 28

What is exploitative competition?

Answer 28

An organism depletes its surrounding of nutrients preventing competitors from accessing resources

Question 29

What can destruction of the microbiota lead to?

Answer 29

Higher risk of infection
Increased allergy risk
IBD

Question 30

What is an antagonistic bacterial relationship?

Answer 30

Harms the other organism

Question 31

What is a symbiotic bacterial relationship?

Answer 31

Organisms and interdependent and rarely live outside the relationship

Question 32

What is a synergistic bacterial relationship?

Answer 32

Organisms cooperate to gain equal advantages

Question 33

What is a biofilm bacterial relationship?

Answer 33

Complex relationships among numerous microorganisms, often different species

Question 34

Definition of a biofilm?

Answer 34

A slimy community of microbes growing on a surface

Question 35

Examples of biofilms?

Answer 35

Plaque on teeth
Soap scum on baths
Slime on rocks in streams
Mucous membranes of digestive system

Question 36

How do biofilms develop?

Answer 36

-free living microbes settle and attach to a surface
- cells produce extracellular matrix
-matrix aids in adherence to other cells
-quorum sensing molecules secreted
-triggers change in biochemistry and shape
-new cells arrive to join and others leave

Question 37

What does an extracellular matrix of a biofilm contain?

Answer 37

DNA
Proteins
Polysaccharides from glycocalyx

Question 38

How does quorum sensing work for biofilms?

Answer 38

-chemicals produced by bacteria
-Bacterial cells have receptors for these chemicals
-as cell numbers increase so do concentrations of quorum sensing molecules
-once these bind and a certain limit exceeded the expression of certain genes are triggered
-enzymes produced, cell shape changes, maintenance of biofilm

Question 39

How do pseudomonas auruginosa use quorum sensing?

Answer 39

Use quorum sensing molecules to determine density
Will only release toxin once dense enough
Otherwise they will be detected too early

Question 40

How could drugs target quorum sensing to treat infection?

Answer 40

Disruption of quorum sensing can inhibit biofilm formation by decreasing cell communication
Amplifying quorum sensing before biofilm formation can inhibit infection by revealing the bacteria to the host before infection can take hold

Question 41

How can biofilms effect antibiotic resistance?

Answer 41

-Layer on top of film may block antibiotic activity
-increased mutational activity in biofilms
-dormant cells in nutrient poor sections of film have decreased metabolic activity but increased doubling time