Humoral Immunity B Cells

Question 1

Are B cells APCs?

Answer 1

yes! they can ingest protein antigens degrade them into peptides and display with MHC II for cd4 cells

Question 2

stimulators of IgM synthesis

Answer 2

polysaccharides and lipids stimulate the production of IgM

Question 3

Where is IgM found on B cells?

Answer 3

on the surface, it is the antibody that resided on surface to attach lipids and polysaccharide

Question 4

stimulators of IgG IgA and IgE antibodies

Answer 4

peptide antigens noticed by CD4 cells lead to induction of production of these

Question 5

B cell maturation cell lineage

Answer 5

stem cell
Pro-B
Pre-B
Immature B
Mature B

Question 6

Ig expression in Pre-B lymphocyte cells

Answer 6

is in the cytoplasm

Question 7

Ig expression in immature B lymphocyte cells

Answer 7

membrane now has IgM

Question 8

Ig expression in mature B lymphocyte cells

Answer 8

have IgM and IgD on membrane

Question 9

Where does clonal expansion of B cells occur?

Answer 9

in the lymph nodes or spleen!

Question 10

Fc and Fab regions of antibodies

Answer 10

Fab regions are antigen binding

Fc regions are not antigen binding

Question 11

What cells bind at Fc region of antibody?

Answer 11

macrophages, neutrophils NK cells, mast, basophils eosinophils

Question 12

IgA locations and function

Answer 12

on body surfaces to protect from outside foreign pathogens

Question 13

IgG locations and function

Answer 13

found in all body fluids

most common antibody
fight bacterial and viral infections

only antibody that can cross into placenta

Question 14

IgM locations and function

Answer 14

found in the lymph and blood

first antibody made in response to an infection

pentamer, large,

Question 15

IgE locations and function

Answer 15

found in lungs skin and mucous membranes

involved in allergic reactions

Question 16

IgD location and function

Answer 16

found on the cell surface of newly synthesized B cells

just a cell surface receptor

Question 17

Antibodies for neutralization?

Answer 17

IgG and IgA

Question 18

Antibody for opsonization?

Answer 18

IgG

Question 19

Antibodies for complement activation?

Answer 19

IgM is best and some IgG

Question 20

Antibody for transport across epithelium?

Answer 20

IgA

Question 21

Antibody for diffusion into extravascular sites?

Answer 21

IgG is best

Question 22

Antibody with highest serum level?

Answer 22

IgG

Question 23

3 types of mature B cells?

Answer 23

follicular B cells
marginal zone B cells
B-1 lymphocytes

Question 24

follicular B cells location and function

Answer 24

in the follicles of spleen and in lymph nodes

can isotype switch, high affinity antibodies produced, long lived plasma cells

Question 25

Marginal zone B cells location and function

Answer 25

in the marginal zone of splenic follicles make IgM and have short loved plasma cells

Question 26

B-1 cells location and function

Answer 26

peritoneal cavity and lymphoid organs and mucosal tissue makes IgM and short lived plasma cells

Question 27

antibody isotype in first compared to second exposure?

Answer 27

in first there will be a lot of IgM and then in second there will be more IgG

Question 28

What is C3d and what is its role in B cell activation?

Answer 28

c3d is the breakdown product of c3b from complement it will bind the Cr2/cd21 receptor on B cells and help activate them when an antigen is attached to its membrane antibody

Question 29

Do B cells have TLRs? What is function?

Answer 29

yes they have them so they can recognize microbial products...it is a linkage between the innate and adaptive immunity

Question 30

How do CD4 cell interacts with B cells

Answer 30

they bind the MHC class II peptides on the B cell

Question 31

What is made by CD4 cells to help B cells proliferate?

Answer 31

cytokines and CD40

Question 32

germinal center of a lymph node function

Answer 32

activated B and cd4 T cells come back to a follicle in the lymph node and cause proliferation of the B cells,..which is the germinal center in the germinal center there is a lot of class switching anf somatic mutations for the antibodies

Question 33

steps of B cell activation and proliferation in a lymph node....

Answer 33

1. CD4 T cell is activated and B cell is activated and goes to the extrafollicular space 2. The effector CD4 cell interacts with a B cell and stimulates it in an extrafollicular space 3. B cell starts to make short lived plasma cells 4. short lived plasma cells and the CD4 T cell go back into a follicle 5. the plasma cells and T cells stimulate the follicle B cells to start proliferating and maturing

Question 34

cytokine inducing switch to IgG antibodies? What T Cell?

Answer 34

Interferon gamma Th1

Question 35

cytokine inducing switch to IgE antibodies? What T cell?

Answer 35

IL-4 Th2

Question 36

cytokine inducing switch to IgA antibodies? What T cell?

Answer 36

cytokines in mucosal tissues like TGF-beta and BAFF Th17