ch 6

Question 1

how does an ag travel in the to LN or spleen

Answer 1

by subcapsular sinus macrophage or as soluble ag

Question 2

how do B cells get ag

Answer 2

actively extract it from apc which isnt requirement but makes it more efficient

Question 3

cSMAC

Answer 3

ag: bCR

Question 4

pSMAC

Answer 4

integrins/ adhesion

Question 5

dSMAC

Answer 5

actin

Question 6

what signal is on ITAMS

Answer 6

YxxL/Ix(6-8)YxxL/I

Question 7

what does the phosphorylation on ITAMS do

Answer 7

acts as a docking point for adapter molecules

Question 8

do B cells need T cell help

Answer 8

yes w some antigens - protein antigen

mice needed bone marrow and thymus grafts for SOME antigens

Question 9

B cells and antigen vs w t cell help

Answer 9

by themselves induce activation and proliferation

w t cells induces memoryand differentiatino

Question 10

what does recognition of ag on B cell lead to

Answer 10

upregulation of MHC II and B7 that then binds to CD28 to upregulate CD40

Question 11

what is CD40 on

Answer 11

the b cell

Question 12

linked recognition

Answer 12

both b and T cell recognize the same protein

may be different epitopes

Question 13

what is the purpose fo the GC

Answer 13

b cell activation

Question 14

how do b cells move in the GC

Answer 14

due to cytokine receptors expression changes

Question 15

what is a characteristic of GCs

Answer 15

they are heterogenous, sometimes one clone will take over ther ties it will be a micture of clones

Question 16

where does SHM occur

Answer 16

in GC

Question 17

what is SHM

Answer 17

individual point mutatinos in heavy and light chains that are followed by selection of the one w best affinity for the ag

Question 18

AID

Answer 18

activation induced cytidine deaminase that prduces opportunity for mutatinos by altering deoxycytidine bases
occurs after SHM

Question 19

what happesn in the light zone of GC

Answer 19

B cells activated
apoptosis for b cells wo T fh help and interaction w FDC or ones that react w self antigen

Question 20

what happnes in the dark zone of GC

Answer 20

SHM and proliferation

Question 21

IgG and IgM and affinity maturation

Answer 21

affinity of igG higher

undergoes affinity maturation while IgM doesnt bc its a pentamer

Question 22

affinity of waht antibody changes after infection

Answer 22

igG

Question 23

differences in antibodies

Answer 23

there are 5 different CH gene sementa nd 5 different heavy chains

Question 24

what antibodies have a J chain

Answer 24

igA and igM

Question 25

what antibodies have a hinge region

Answer 25

igG
igD
igA

Question 26

what regulates class switch recombination

Answer 26

T cells and causes change in isotype

BUT THE ANTIGEN BINDING SPECIFICITY DOESNT CHANGE

Question 27

differences within isotypes of antibodies

Answer 27

some isotypes have subclasses and all igH can pair with lambda or kappa light chain