Antibodies

Question 1

what produces antibodies?

Answer 1

B lymphocytes

Question 2

what are the central lymphoid organs, and what process occurs there?

Answer 2

• bone marrow
• thymus

lymphocytes differentiate there (B cells, bone marrow) (T cells, thymus)

Question 3

what are the peripheral secondary lymphoid organs?

Answer 3

• lymph nodes
• spleen
• GALT (gut-associated lymphoid tissue)
• peyers patches
• tonsils
• appendix

Question 4

what are naive B cells?

Answer 4

B cells that have not met antigens, and circulate from blood into peripheral lymphoid tissues

Question 5

where is the main site of antigen encounter?

Answer 5

peripheral lymphoid tissues

Question 6

describe organisation of lymph node?

Answer 6

cortex and inner medula

cortex:
- outer section of B cells follicles
- paracortical area of T cells and dendritic cells

medulla:

• macrophages
• antibody secreting B cells (plasma cells)

Question 7

what is the pathway of blood carrying lymphocytes and antigen through the spleen?

Answer 7

• enter from a trabecular artery into a central arteriole
• pass into a marginal sinus
• exit through a trabecular vein

Question 8

what are features of the memory antibody response?

Answer 8

1. faster
2. can produce more antibody
3. does not prevent you from making a response to another antigen

Question 9

what are the two separate functions of antibodies?

Answer 9

1. to bind the pathogen that elicited its production

2. to recruit other cells and molecules that will lead to clearance or destruction of pathogen

Question 10

what determines antigen specificity?

Answer 10

three hypervariable loops that form a surface complimentary to antigen

Question 11

how is Ab diversity created?

Answer 11

1. rearranging multiple gene segments
2. junctional diversity
3. different combinations of H and L chains
4. somatic hypermutation

Question 12

what are the 5 classes of Ab?

Answer 12

• IgA
• IgD
• IgE
• IgG
• IgM

Question 13

which antibodies predominate in plasma?

Answer 13

IgG and IgM

Question 14

what are the main isotypes of antibody in extracellular fluid?

Answer 14

IgG and monomeric IgA

Question 15

where does dimeric IgA predominate?

Answer 15

• secretions across epithelia, including breast milk

Question 16

what antibody does a foetus receive by transplacental transfer?

Answer 16

IgG

Question 17

where is IgE found?

Answer 17

mostly near to epithelial surfaces, especially gut, lungs and skin

Question 18

where is free of Ab?

Answer 18

the brain

Question 19

what is infliximab for?

Answer 19

• anti-tumour necrosis factor (inflammatory mediator)

- used in rheumatoid arthritis, ankylosing spondylitis, psoriasis, inflammatory bowel diseases

Question 20

what are examples of monoclonal antibodies?

Answer 20

• infliximab
• herceptin
• gleevac

Question 21

what is herceptin for?

Answer 21

• anti HER2 (human epidermal growth factor receptor 2)

- can block growth and lead to destruction of breast tumour cells that express high levels of HER2

Question 22

what is gleevac for?

Answer 22

• anti-typrosine kinase

- effective against chronic myeloid leukaemia