B-cells

Question 1

Describe IgG

Answer 1

Most abundent in the blood
Activate neutrilization + opsonisation
Crosses the placenta - passive immunity
Targets - bacteria + virus

Question 2

Describe IgA

Answer 2

dimer - monomer in blood
present in secreations
protects the mucousal membranes
in brest milk for passive immunity
targets bacteria and virus

Question 3

Describe IgD

Answer 3

monomer
acts as a BCR
in conjunction with IgM

Question 4

Describe IgM

Answer 4

pentramer
present on naive cells
activates complement well
acts as a BCR

Question 5

Describe IgE

Answer 5

Monomer
attacks multicellular paracits
causes allergic reactions (pollen + penacillin)
Strong immune response, degranulates mast cells

Question 6

Describe a primary reponse

Answer 6

take 7-14 days
will have a low concentration of antibody
primarly IgM

Question 7

describe a secondary repsonse

Answer 7

takes 2-3 days
high concentration of antigen
primary IgG - also IgE and IgA

Question 8

What are memory B-cells

Answer 8

During plasma cell division some become memory B-cells
Contain parent B-cell BCR
Memory BC rapidly becomes plasma cell and activates secondary reponse
Stimulates helper T-cells with antigen

Question 9

What are the functions which Antibody can cuase

Answer 9

Neutrilisation - binds to receptors to neutrilise a virus binding sites
Opsomisation - Binds to native antigen to act as a binding site for phagocytes
Complement - classical complement pathway binds to antibody causes MAC kill pathogen

Binds to epitots

Question 10

What antigen do antibodys bind to

Answer 10

Epidotes which are binding sites for antigen
Native antigen = antigen which is unprocessed

Question 11

Descibe a B-cell receptor

Answer 11

Made from 2 identical heavy chains
2 ideantical light chains
Tranmembrane region binding to the B-cell
has variable regions on the ends of the chains

Question 12

How are B-cells activated

Answer 12

BCR binds to antigen
And T-cell releases cytokines
Cells surface contains 100,000 identical BCR

Question 13

Describe the lifetime of a B-cell

Answer 13

Development in the bone marrow
Scrambling of the BCR varible genes
Moves to lymph node + spleen
When activated becomes a plasma cell - secreating antibody
divides lots producing some memory B-cells

Question 14

What is the development of B-cells

Answer 14

In the bone marrow developes
Self tollerance
Immunocompitance