Immune Response to Infection

Question 1

What are the key mediators of immunity?

Answer 1

Phagocytes and lymphocytes are key mediators of immunity

Question 2

What is the role of phagocytes?

Answer 2

internalize pathogens and degrade them

Question 3

What do B cells do?

Answer 3

Make antibodies - that are also effective against extracellular pathogens

Question 4

What do T helper cells do?

Answer 4

Coordinate the immune response by direct cell-cell interactions and the release of cytokines

Question 5

What are the two essential features of the adaptive immune syste?

Answer 5

Specificity and memory

Question 6

Which immune response is able to mount a more effective response on second and subsequent encounter with a particular antigen?

Answer 6

The adaptive immune response

Question 7

Which immune response does not alter on repeated exposure to an infectious agent?

Answer 7

Innate immune response

Question 8

What are antigens?

Answer 8

Molecules that are recognised by receptors on lymphocytes

Question 9

How do B and T cells differ in their interactions with antigen molecules?

Answer 9

B cells usually recognise intact antigen molecules, whereas T cells generally recognise antigen fragments that are displayed on the surface of the bodys own cells - in MHC

Question 10

what are the two phases of the immune response?

Answer 10

Antigen recognition & antigen eradication

Question 11

Which T Helper cells release IFN-Gamma?

Answer 11

Th1

Question 12

Which interleukins are released by Th2?

Answer 12

IL-4/IL-5/IL-13

Question 13

Which interleukins are released by Th17?

Answer 13

IL-17/IL-22

Question 14

What is the principal function of the immune system?

Answer 14

To distinguish self from non-self

Question 15

How does an immune response end?

Answer 15

1. Clears pathogen
2. Stops inflammatory cytokine production
3. Repair tissue damage

Question 16

What are PAMPs?

Answer 16

Pathogen Associated Molecular Patterns - These are features shared by classes of microbes that are recognised by identical toll like receptors

Question 17

What is a major pattern recognition molecule in E.Coli?

Answer 17

Lipopolysaccharide - LPS

Question 18

What are four types of anti-viral genes which Interferons stimulate the synthesis of?

Answer 18

1. Nucleases
2. Inhibitors of viral entry/exit
3. Inhibitors of viral uncoating and replication
4. Inhibitors of protein translation

Question 19

What are the three immunomodulatory roles of interferon?

Answer 19

Enhance T cell responses
Anti-inflammatory actions
Tissue Repair

Question 20

How does an NK cell recognise a virus-infected cell?

Answer 20

Through the down regulation of MHC on the surface

Question 21

Which of the three types of interferon promote antiviral responses?

Answer 21

Type I and III

Question 22

Which type of interferon promotes antibacterial immunity?

Answer 22

Type II

Question 23

Why are dendritic cells better at responding to viral infections than macrophages?

Answer 23

Dendritic cells can produce a lot of type 1 interferon during infection

Question 24

How do dendritic cells present antigens to T cells?

Answer 24

Through MHC molecules

Question 25

What happens when a naive t cell binds MHC with antigen from a dendritic cell?

Answer 25

This coupled with the release of cytokines causes the T cell to release more cytokines which act in an autocrine manner and help the T cel differentiate into specific T cells to fight that particular pathogen

Question 26

Which cytokines convert the naive T cell into one that fights fungi and extracellular bacteria?

Answer 26

Th17 - needs IL-17 and IL22

Question 27

Which cytokines convert the naive T cell into one that fights intracellular pathogens?

Answer 27

IFN-Gamma

Question 28

Which cytokines convert the naive T cell into one that fights helminths?

Answer 28

IL-4 IL-5 IL-13

Question 29

How do T cells help B cells produce Antibodies?

Answer 29

1. APC's are activated by infection and cytokines 2. They present antigen to T cells - T cells activated by cognate MHC and foreign peptide recognition 3. B cells become licensed for antibody production against the antigen being present on the BCR 4. Antibodies are produced

Question 30

What are the two components of an antibody-mediated enhanced anti-microbial response?

Answer 30

1. Phagocytosis (opsonisation) | 2. Complement activation

Question 31

what are the four broad roles of T cells?

Answer 31

1. Phagocyte activation 2. Direct killing of infected cells 3. B cells activation 4. Innate lymphoid cells

Question 32

Which cytokines do eosinophils produce? And what T cell do these result in?

Answer 32

IL-4, IL-5 and IL-13 | makes Th2

Question 33

What is the timing of the innate immune response?

Answer 33

0-12 hours post infection

Question 34

Which immune cells are present in the first 12 hours following infection?

Answer 34

Mast cells, Dendritic cells, NK Cells, Phagocytes, Epithelial barriers, complement

Question 35

What results in the production of B and T cells after a few days following infection?

Answer 35

Antgen presentation to T Lymphocytes

Question 36

How many weeks after exposure to antigen X does the peak of the primary anti-X response occur?

Answer 36

1 weeK

Question 37

Describe the secondary immune response in relation to the primary immune response?

Answer 37

It is much faster and greater in effect

Question 38

At what age does thymic declines?

Answer 38

halts at a low level at about 30

Question 39

What happens to the percentage of T cells in the blood that are Naive T cells as you age?

Answer 39

Decreases

Question 40

What happens to the percentage of T cells in the blood that are Memory T cells as you age?

Answer 40

INcreases