Antibody, Lymphocytes & Generation of Diversity (#3)

Question 1

What happens in the secondary immune response?

Answer 1

• booster immunisation
• shorter lag period
• total antibody, IgM + IgG inc greater after
• after 10 days, IgM declines
• IgG inc quicker + higher as pre-cursor freq + affinity of cells higher
• IgG + total antibody decline after 15 days

Question 2

What are monoclonal antibodies?

Answer 2

• powerful reagents + biological therapeutics used to treat diseases from autoimmune diseases e.g. RA, inflammatory disease, cancer

Question 3

How do normal B cell pops differ to monoclonal antibodies?

Answer 3

• are polyclonal even when some cells have formed memory clones
• also indiv cells comprising memory clones most likely be diff due to somatic hypermutation
• when activated - polyclonal response = mix of all specialities to diff components of immunising antigen
• but monoclonal antibodies v. specific to particular antigen + targets it on large scale

Question 4

How are monoclonal antibodies gen?

Answer 4

• expansion as clones of single B cell

- can mature into plasma cells that all secrete same antibody

Question 5

Why are mouse monoclonal antibodies not good therapeutics?

Answer 5

• mouse protein can be seen as foreign antigen + immune responses against antibody gen

Question 6

What is chimeric antibody?

Answer 6

mouse monoclonal engineered so mouse variable region of heavy + light chains ass with human constant regions

Question 7

What do chimeric antibodies end in and give an e.g.?

Answer 7

• ximab
• e.g. rituximab is antibody to CD20 expressed by B cells
• targets B cells for killing + removes them from circ + lymphoid tissues
• effective against B cell lymphomas + some autoimmune diseases e.g. RA

Question 8

What are humanised monoclonal antibodies?

Answer 8

• only the parts of the variable region that contact antigen are from the mouse
• bits that don’t contact antibody are human

Question 9

What do humanised antibodies end in + give an e.g.?

Answer 9

• zumab

- e.g. omalizumab - specific for IgE + can be used to treat moderate to severe asthma

Question 10

What do fully human monoclonal antibodies end in + give an e.g?

Answer 10

• umab

- adalimumab - specific for TNF alpha + used to treat inflammatory diseases e.g. arthritis + IBD

Question 11

How are genes encoding ABO antigens inherited + expressed?

Answer 11

• inherited from parents

- expressed co-dom

Question 12

List the 4 types of red cell antigen

Answer 12

1. O
2. A
3. B
4. AB

Question 13

What does having an O red cell antigen mean?

Answer 13

have no gene expressing A/B determinants inherited from either parent

Question 14

What does having an A red cell antigen mean?

Answer 14

expresses A inherited from each parent or A from 1 + O from other

Question 15

What does having an B red cell antigen mean?

Answer 15

expresses B inherited from each parent or B from 1 + O from other

Question 16

What does having an AB red cell antigen mean?

Answer 16

inherits gene encoding A + B from both parents

Question 17

How do antibodies exist in circ to antigens?

Answer 17

exist in circ to antigens not expressed by RBCs

Question 18

What antibodies do those with O red cell antigens have?

Answer 18

circ antibodies to A + B (Anti-A,B)

Question 19

What antibodies do those with A red cell antigens have?

Answer 19

circ antibodies to B (Anti-B)

Question 20

What antibodies do those with B red cell antigens have?

Answer 20

circ antibodies to A (Anti-A)

Question 21

What antibodies do those with AB red cell antigens have?

Answer 21

no circ antibodies to A/B

Question 22

Which antibodies do those with O red cell antigens react with?

Answer 22

None

Question 23

Which antibodies do those with A red cell antigens react with?

Answer 23

Anti-A in serum

Question 24

Which antibodies do those with B red cell antigens react with?

Answer 24

Anti-B in serum

Question 25

Which antibodies do those with AB red cell antigens react with?

Answer 25

Anti- A+ B in serum

Question 26

Why are those with O red cell antigens universal donors and not recipients?

Answer 26

• can only receive RBCs with O bc serum has circ Anti-A + B which will react with any RBCs that express A, B/AB antigen
• but is unviersal donor as has circ Anti A + B

Question 27

Who can those with A red cell antigen donate to?

Answer 27

• blood group A/AB bc don’t have circ Anti-A in serum

Question 28

Who can those with B red cell antigen donate to?

Answer 28

• blood group B/AB bc don’t have circ Anti-B in serum

Question 29

Who can those with AB red cell antigen universal recipients + not donors?

Answer 29

• can’t donate to any groups bc they have circ Anti-A, B + AB in serum
• is universal recipient bc have no circ Anti-A, B

Question 30

What does Rhesus +ve mean?

Answer 30

expresses antigen on RBC

Question 31

What does Rhesus -ve mean?

Answer 31

doesn’t expresse antigen on RBC

Question 32

What happens when a mother who is Rh- gives birth to a baby who is Rh+?

Answer 32

mother exposed to Rh antigen on baby’s RBCs + makes IgG antibodies to Rh antigen

Question 33

What causes haemolytic disease?

Answer 33

• if 2nd baby also Rh+, IgG can cross placenta + enter baby’s circ
• IgG targets Rh antigen + causes RBC lysis in foetus + haemolytic disease in newborn

Question 34

How is haemolytic disease cured?

Answer 34

• plasmaphresis = IgG antibodies removed from baby’s system + baby can create own RBCs