Immunology

Question 1

neutrophils intracellular granules?

Answer 1

• primary lysosomes that combine with phagosomes containing microbes to digest
• secondary granules that have Fc and complement receptors

Question 2

eosinophil granules contain?

Answer 2

MBP - major basic protein

Question 3

mast cells v basophils?

Answer 3

• mast cells are fixed in tissue whereas basophils circulate in blood around body

Question 4

types of T cells?

Answer 4

• TH1 -> CD4 for intracellular pathogens
• TH2 -> CD4 for extracellular pathogens
• Tc cells -> CD8
• Tr - regulate immune system and found in blood, lymph nodes and spleen

Question 5

what do NK cells express?

Answer 5

CD56

Question 6

what is the complement?

Answer 6

A complex series of interacting plasma proteins which form a major
effector system for antibody-mediated immune reactions

Question 7

what do ‘a’ in complement do?

Answer 7

these are minor cleavage fragments and have important biological properties in the fluid eg, C3a and C5a which increase chemotaxis

Question 8

what do ‘b’ in complement do?

Answer 8

major fragments and can bind to cell membranes or trigger complex for the next complement component eg, C4b induces opsonisation (MAC)

Question 9

what routes can cause cleavage of C3?

Answer 9

• classical (antibody mediated)
• alternative (spontaneous and doesn’t need antibody)
• lectin (independent of antibodies)

Question 10

IgG?

Answer 10

• majority

- only immunoglobulin to cross placenta

Question 11

IgA

Answer 11

• predominant in mucous secretion

Question 12

IgM?

Answer 12

• primary response
• large and so mainly found in the blood
• has multiple complement binding sites

Question 13

IgE?

Answer 13

• basophils and mast cells have high affinity

- associated with allergic reactions

Question 14

IgD?

Answer 14

• expressed on naive B cells and act as B cell antigen receptors

Question 15

IFN?

Answer 15

• Alpha & beta -> virus

- gamma -> activated by Th1 cells

Question 16

pro inflammatory and anti-inflammatory IL eg?

Answer 16

pro- IL1

anti - IL10

Question 17

PAMPS?

Answer 17

Pathogen Associated Molecular Patterns eg lipopolysaccharide

Question 18

PRR?

Answer 18

Pattern Recognition Receptors eg Toll like receptors (cell damage) and Nod like receptors (detect intracellular microbial pathogens)

Question 19

MHC 1?

Answer 19

• intracellular eg, Virus
• found on surface of all cells except RBC
• CD8

Question 20

MHC II?

Answer 20

• extracellular
• found on APC
• CD4

Question 21

atopy?

Answer 21

Atopy - Inherited tendency for overproduction of IgE antibodies to common
environmental antigens

Question 22

type 1 hypersensitivity reaction?

Answer 22

• IgE mediated
• immediate
  eg, hay fever or anaphylaxis

Question 23

type 2 hypersensitivity reaction

Answer 23

IgE/IgM is bound to cell surface antigens

eg, transfusion reactions

Question 24

type 3 hypersensitivity reactions?

Answer 24

immune complexes, activation of complement/IgG

eg, Systemic lupus erythematosus

Question 25

type 4 hypersensitivity reaction

Answer 25

cell mediated delayed

eg, TB and contact dermatitis

Question 26

live attenuated vaccines pros and cons?

Answer 26

pros; stimulates memory T and B cells

cons; risk of infection in the immunocompromised

Question 27

inactive pathogen vaccines pros and cons?

Answer 27

pros; no risk of infection

cons; lack of T cell involvement

Question 28

recombinant vaccines pros and cons

Answer 28

pros; no risk of infection and safer handling

con; weaker immune response and repeat vaccination & adjuvants required

Question 29

DNA vaccines pros and cons?

Answer 29

pros; do not require complex storage

cons; need boosting