B cell activation and antibody production part 2 Flashcards Preview

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Flashcards in B cell activation and antibody production part 2 Deck (30):
0

activation of B cells is initiated by?

specific antigens by surface BCR's

1

Progeny of the clone may differentiate into plasma cells that produce___ or isotype switch

IgM...

2

B cell differentiation results in an increasing fraction of the ___ protein produced as the secreted form

U (meu)

3

in T dependent response, some the progeny activated IgM and IgD expressing B cells undergo ? and produce abs with heavy chains of different classes. delta, alpha, and epsilon

Heavy Chain Isotype switching

4

Where does Isotype switching occur?

germinal centers driven by Follicular T helper cells

5

class switching occurs in response to?

changing the constant regions of heavy chains

6

Activated B cells can secrete IFN-gamma and isotype switch to a plasma cell that secretes?

IgG to activate complement system.

7

helminth infections likely influence Follicular T helper cell differentiation to these cells, which produce Th-2 type cytokines during the germinal center reaction.

IL-4+ Follicular T helper cells

8

B cells in mucosal tissue switch to?

IgA secreting plasma cells

9

Switching to IgA involves?

TGF-beta

10

in Immunodeficiencies related to the CD40-CD40L axis the antibody response to protein antigens is dominated by

IgM antibodies

11

The mature B cells first produce IgM Ig's. the rearranged VDJ sequences are positioned directly adjacent to other C genes. Every C gene is preceded by ___that controls the rearrangement process

Switching the S sequence

12

what is the key enzyme required for isotype switching and affinity maturation?

Activation Induced Cytosine Deaminase (AID)

13

AID expression is activated by?

CD40 signals from follicular T cells

14

AID deaminates cytosines in ss-DNA converting Cytosine residues to?

Uracil residues

15

During the actual binding of B cells to the T helper cell surface, which is not involved?

Ig

16

if you could analyze at the molecular level a plasma cell making IgA ab, you wouldnt find?

mRNA specific for U (meu) heavy chains

17

Affinity maturation is observed ONLY in antibody response to?

T-dependent protein antigens

18

somatic hypermutation of Ig V genes and selection of B cells with high affinity Ag recep

.....

19

what happens in the dark zone of germinal centers?

proliferation and point mutation in V-region of H/L chains

20

Mutated Ig with higher affinity binds antigen presenting FDC and survives in the?

light zone of germinal centers

21

mutations in which genes, increase with time after immunization and with repeated injections?

V genes

22

Multiple myeloma is a cancer which has arisen from a

plasma cell

23

many non protein antigens, such has polysaccharides and lipids, stimulate ab production in the absence of Th cells

.....

24

T-independent responses involve which type of antigens?

non-protein: polysaccharides and lipids

25

T-dependent responses involve which type of antigens?

protein

26

these cells respond readily to the T-independent antigens mainly in the peritoneum and in mucosal sites

B-1 cells

27

CD4+ helper T cells cannot recognize which type of Antigens?

T-independent antigens: polysaccharides, glycolipids, and nucleic acids

28

what is the function of the complementarily determining region of an Ig?

determine antibody specificity and are found on both the heavy and the light chains

29

if you wanted to check for the presence of memory B cells from your vaccine subjects by taking some of their B cells and re-stimulating them in vitro with antigen, the best place to get some memory cells would be from?

Blood