Lektion 9 - Defence systems

Question 1

What is immunity? (three functions)

Answer 1

• Defence agains invading pathogens
• Removal of “worn-out” cells and tissue debris (red blood cells, wound healing)
• Elimination of abnormal cells (cancer)

Question 2

What is a pathogen?

Answer 2

Any organism with the potential to cause disease (bacteria, viruses, parasites and fungi)

Question 3

What are the functions of the immune system? (broadly)

Answer 3

Snese pathogen

Activate effectors

Shut off immunesystem

Question 4

How does the cell recognize danger?

Answer 4

By a ligand-receptor interaction

Question 5

What is a possitive feeback loop in the immune response?

Answer 5

• enhanced the response
• eliminate the threat

Question 6

What is the negative feedback loops in the immune response?

Answer 6

• shut off the response
• Wound healing

Question 7

What are the two types of immunity?

Answer 7

Innate immunity and acquried/adaptive immunity

Question 8

What are the properties of innate immunity? (3st)

Answer 8

1) Rapid (hours)
2) Limited specificity and diverse (traits shared among pathogens)
3) trained immunity, short term

Question 9

What type of organisms have innate immunity?

Answer 9

• invertabrate
  -vertabrate

Question 10

What are th eproperties of acuired/adaptive immunity? (3st)

Answer 10

1) slow (days)
2) highly specific and diverse (specific pathogen traits)
3) memory: secondary response is faster and stronger

Question 11

What are the two types of effectors?

Answer 11

Cellular components and soluble effectors

Question 12

What are the functions of cellular components?

Answer 12

• Effector function: eat and/or kill
• Regulatory function: activate other cell types

Question 13

What are the properties of soluble effectors?

Answer 13

• Alert and coordination (cytokines)
• Recruitment (chemokines)
• Killing (toxic molecules, pore forming effectors and antibodies)

Question 14

what are the primary lymphoid organs?

Answer 14

Bone marrow and thymus

Question 15

What happens in the bone marrow?

Answer 15

Hematopoiesis and B cell maturation

Question 16

What happens in the thymus?

Answer 16

T cell maturation

Question 17

Why are there so many cell types?

Answer 17

Because every pathogen needs to be detected (oklart om detta stämmer)

Question 18

What are the sentinels and what do they do?

Answer 18

Detect intruder (receptors) and alert the body (cytokines)

Question 19

Innate immunity:
What are the mechanical defenses? (4st)

Answer 19

• Skin (thick multilayer barrier)
• Respitory trackt (mucociliary epithelium and cough reflex)
  -Alimentary tract: gastric acid, digestive enzymes, and bile etc
• Genetal tract (urine flow, acid urine, acid enviroment (vaginal lactobacili)

Question 20

Innate immunity:
What is the microbiological barrier?

Answer 20

Microbiota competition for niche and nutriens ex on the skin.

Question 21

Innate immunity:
How does bacteria on or skin work with other infectous bacteria?

Answer 21

It can prevent the “bad” bacteria from spreading by competing.

Question 22

Innate immunity:
How does the immune system sense danger?

Answer 22

By receptor binding (triggers cascade)

Question 23

What is a PRR?

Answer 23

Pathogen recognition receptors - Detection of intruders

Question 24

Innate immunity:
What is phagocytosis?

Answer 24

When a phagocyte removes a pathogen by “eating it”

Question 25

What is acquired immunity?

Answer 25

A part of the immune system that uses specialized cells to fight off pathogens

Question 26

What is an antigen?

Answer 26

A molecule which is recognised specifically by B cells (Ab) or T cells (TCR)

Question 27

What is an epitope?

Answer 27

A specific part of an antigen which is recognised by B/T cells

Question 28

How are there many more Abs and TCRs than there are genes?

Answer 28

By multiple genes and random gene rearengement.

V, D and J
There are several parts of the gene that forms loops and cuts of unecessary genes that are not needed for a specific Abs or TCR

Question 29

What are the two different subsets of T cells?

Answer 29

T Killer (CTL) - kill virus infected cells

T Helper (Th) - Help activation B cells (cytokines)

Question 30

What odes T-cells require to be activated?

Answer 30

A dual signal:
1) Specificity (antigen)
2) danger recognition (costimulatory molecules)

Question 31

The CH region on an antibody comes in different classes, why?

Answer 31

Because they have different functions

Question 32

What are the four functions of antigens?

Answer 32

1) ADCC
2) opsonization (eat better)
3) Neutralization
4) Complement activation (classical pathway)

Question 33

What does B cells need to be activated?

Answer 33

An interaction with a T helper cell (the T helper cell needs two signals to itself be activated)

Question 34

What is the full picture of the Acquired immune system? (3 steps)

Answer 34

1) T killer: goes to peripherym kill
2) T helper: secondary lymphoid organs, activate B cells
3) T helper: goes to the periphery, activate macrophage