Module 5

Question 1

Immunity

Answer 1

ability to resist infectious diseases

Question 2

2 Mechanisms mediating resistance

Answer 2

Innate defenses and adaptive defenses

Question 3

2 innate defenses types

Answer 3

surface barriers and internal defenses

Question 4

2 adaptive defenses

Answer 4

humoral and cellular immunity

Question 5

3 barriers of entry of pathogens and eg.

Answer 5

physical - skin, mucus
chemical - acid Ph, enzymes `
biological competition - commensals in gut and skin compete with pathogens

Question 6

properties of innate immunity

Answer 6

rapid acting
similar response each time
initiates inflammation

Question 7

Phagocytes

Answer 7

neutrophils, monoctyes and macrophages and dendrite cells

Question 8

neutrophils

Answer 8

70% of WBC, first cell to migrate to infection site

Question 9

macrophages

Answer 9

phagocytes resident in tissues. blood precursors are monocytes

Question 10

Other innate immune cells

Answer 10

Mast cells, basophils, eosinophils and natural killer cells

Question 11

initiation of inflammation

Answer 11

• leukocytosis
• margination
• diapedesis - cells squeezing out
• chemotaxis

Question 12

how to innate immune cells recognize pathogens

Answer 12

PAMP’s, which are recognized by PRR

Question 13

4 responses to PAMP’‘S

Answer 13

• Secretion of cytokines
• recognition of organisms for phagocytosis
• enhanced killing
• maturation of dendritic cells

Question 14

TLR’s and 2 examples

Answer 14

key pattern recognition receptors (PRR) for PAMP’s expressed by innate immune cells.
eg. LPS and flagellin

Question 15

where do immune cells develop

Answer 15

bone marrow

Question 16

where do T cells mature

Answer 16

thymus

Question 17

Steps in lymphatic system

Answer 17

• blood leaves capillaries and enters tissues
• fluid drains out of tissues into capillaries and vessels
• lymph fluid returns to blood stream via thoracic duct
• lymph nodes are filled with immune cells and act as filters

Question 18

Acquired immunity cells

Answer 18

Lymphocytes- T and B cells

Question 19

Function of T and B cells

Answer 19

T - provide cell mediated immunity through Cytotoxic T Lymphocytes (CTL) and Helper T cells

B - Secrete antibody proteins which give humoral immunity

Question 20

Key feature of acquired immunity

Answer 20

has a specific memory

Question 21

5 antibody classes

Answer 21

1. IgM
2. IgG
3. IgA
4. IgE
5. IgD

Question 22

4 ways antibodies act

Answer 22

1. neutralisation - antibody binding to virus can block its entry
2. opsonisation to promote phagocytosis
3. activation of complement system
4. triggering if mast cells to release histamine

Question 23

B and T cell recognition

Answer 23

B cells recognise small region of whole antigen (epitope)

T cells recognise short peptides of antigen, bound on surface of antigen presenting cell (APC) on an MHC molecule.

Question 24

2 Consequences of antigen recognition

Answer 24

• Proliferation - colonial expansion

- Differentiation - cells mature effector cell

Question 25

Different approaches to vaccination

Answer 25

- live attenuated - inactivated pathogens - subunit - toxoid - live vectored - mNRA - DNA

Question 26

PAMPS vs Antigens

Answer 26

PAMPS -stimulates innate immune response which alerts DC to infection Antigen- recognised by t cell receptor (signal 1)

Question 27

Heard Immunity + equation

Answer 27

when enough people are immune, infection runs out of hosts qc=1-R0

Question 28

dendritic cells

Answer 28

major APC CELLS Mature and migrate to lymph nodes

Question 29

MHC cell

Answer 29

display antigen to T cell. highly variable

Question 30

Activation of T cell requires

Answer 30

1. signal 1 - t cell receptor binding MHC to Ag | 2. Signal 2 - costimulatory signal

Question 31

Phases of vaccine development

Answer 31

1. pre - clinical 2. phase 1 human 3. phase 2 human 4. phase 3 human 5. regulatory review

Question 32

Public education to anti vax

Answer 32

- accurate information - vaccine safety explained - rick benefit analysis

Question 33

what is both signals needed in any vaccine

Answer 33

PAMPS and Antigens

Question 34

adjuvant

Answer 34

what vaccines use with purified protein to provide innate immune stimulus formally given by PAMPS .

Question 35

what does a vaccination do

Answer 35

aims to prime the adaptive immune system to the antigens of a particular microbe so the first infection includes a secondary response.

Question 36

Critical immunisation threshold

Answer 36

fraction of people who need to be vaccinated to stop a disease circulating

Question 37

R 0- basic reproductive number

Answer 37

average number of people who will be infected by one infectious persons

Question 38

Causes of immunodeficiency diseases

Answer 38

Genetic or due to exposure

Question 39

Examples of immunodeficiency disorders

Answer 39

SCID, AIDS, HIV

Question 40

Auto Immunity

Answer 40

- failure of tolerance | - system or organ specific

Question 41

Examples of autoimmune diseases

Answer 41

- Type 1 diabetes - narcolepsy - multiple sclerosis - allergies

Question 42

Requirement for allergies

Answer 42

1. prior sensitisation to allergen - results in production of IgE 2. allergen binding to IgE mast cells 3. severe response leads to anaphylactic shock

Question 43

Hygiene hypothesis

Answer 43

birth order and expose to kids affects allergy likelihood

Question 44

What alters our microbiome

Answer 44

- bottle feeding and caesarian - antibiotics - household cleanliness - indoor / urban lifestyle - diet and obesity