Immunology

Question 1

There exists an evolutionary arms race between pathogen and host. What does this mean?

Answer 1

Pathogen exploits flaws in the defensive barriers of its host
The host evolves to correct those flaws
Pathogen replicates and evolves to evade corrections to exploit other flaws
Pathogen has ability to replicate much faster than the host; host relies on flexible and rapid immune response to combat

Question 2

Some features of skin that contribute to barring infection include…

Answer 2

Tightly packed keratinised cells undergo renewal constantly; limits colonisation
Low pH kills pathogens
Sebaceous glands secrete oils and enzymes to destroy bacterial cell walls

Question 3

The innate immune system has a ___ response and is ____ to micro-organisms

Answer 3

Fast, non-specific

Question 4

The adaptive immune system has a ___ response and is ____ to micro-organisms

Answer 4

Slow, specific

Question 5

The 5 types of leukocytes (WBCs)?

Answer 5

Neutrophils, Monocytes, Lymphocytes, Eosinophils, Basophils + Mast cells

Question 6

Primary lymphoid tissue?

Answer 6

Bone marrow, thymus

Question 7

Secondary lymphoid tissue?

Answer 7

Spleen, tonsils (any sites of AIS activation)

Question 8

List the leukocyte components of the innate immune system

Answer 8

Macrophages, neutrophils, dendritic cells, basophils, mast cells, eosinophils, NK cells

Question 9

List the protein components of the innate immune system

Answer 9

Complement, acute phase, cytokines

Question 10

Basophils and mast cells mature in bone marrow. True/false?

Answer 10

False

Basophils mature in bone marrow; mast cells mature once in tissue

Question 11

Basophils and mast cells are mainly involved in ____. They secrete ____, leading to _____…

Answer 11

Allergic reactions

Secrete histamine and inflammatory mediators, leading to increased vascular permeability and smooth muscle contraction

Question 12

The main function of phagocytes is?

Answer 12

“Eat” cells by ingesting them and mopping up debris

Neutrophils, macrophages and dendritic cells mainly involved in phagocytosis

Question 13

PRRs recognise what on bacteria/viruses?

Answer 13

PAMPs

Not expressed by human cells

Question 14

Opsonins enhance…

Answer 14

Phagocytosis

Act as a bridge between pathogen and phagocyte receptors

Question 15

Major opsonins include…

Answer 15

C3b, CRP, IgG/IgM

Question 16

Acute phase proteins are produced by…

Answer 16

The liver

Question 17

The function of cytokines is to…

Answer 17

Respond to infection. Modulate the behaviour of cells, locally and systemically

Question 18

Interferons are important in…

Answer 18

Limiting viral infections

Question 19

Interleukins are important in…

Answer 19

Directing cells to divide/differentiate

Mainly produced by T cells (IL-2 important for T cell activation)

Question 20

Chemokines are important in…

Answer 20

Control and direct cell migration

Question 21

Complement involves enzymatically activating proteins in a…

Answer 21

Biological cascade, resulting in a rapid response

Question 22

Functions of C3a and C5a

Answer 22

Inflammatory mediators - recruit phagocytes

Question 23

List the leukocyte components of the adaptive immune system

Answer 23

B lymphocytes, T lymphocytes

Question 24

List the protein components of the adaptive immune system

Answer 24

Antibodies, cytokines

Question 25

Antibodies act as opsonins. True/False?

Answer 25

True

Question 26

Antibodies are Y shaped glycoproteins made up of...

Answer 26

Two heavy chains and two light chains | Heavy chains have variable regions; light chains have constant regions

Question 27

List the immunoglobulins found in the blood, from most to least abundant

Answer 27

IgG, IgA, IgM, IgD, IgE

Question 28

Main function of IgG

Answer 28

Provides antibody-mediated immunity to developing foetus and neonates

Question 29

Main function of IgA

Answer 29

Secretory; found in breast milk, saliva, tears | Defence at mucosal surfaces

Question 30

Main function of IgM

Answer 30

Found in blood; first Ig produced during infection

Question 31

Main function of IgD

Answer 31

Unknown; protection against URT infections

Question 32

Main function of IgE

Answer 32

Activates mast cells (causes degranulation)

Question 33

T cell antigen receptors can recognise free antigens. True/False?

Answer 33

False | Need to be presented as a complex with MHC molecules

Question 34

MHC I presents to?

Answer 34

CD8+ T cells | Expressed on all nucleated cells

Question 35

MHC II presents to?

Answer 35

CD4+ T cells | Expressed only on antigen presenting cells (dendritic cells, B cells, macrophages)

Question 36

T cell activation requires...

Answer 36

MHC binding to T-cell receptor | B7 binding to CD28

Question 37

B cell activation requires...

Answer 37

Antigen binding to B-cell receptor PRRs recognising PAMPs Optional co-stimulation by CD4+ cells through CD40L

Question 38

Function of IL-2

Answer 38

Activates CD8+ cells

Question 39

Function of IL-4, IL-5 and IFNy

Answer 39

Activate B cells; increase killing

Question 40

3 different types of memory cells

Answer 40

Helper T-cells B-cells Cytotoxic T-cells

Question 41

Name some pro-inflammatory cytokines

Answer 41

IL-1 IL-6 TNF

Question 42

What effect do pro-inflammatory cytokines such as IL-6 have on the liver?

Answer 42

Stimulate release of acute phase proteins (CRP, C3...)