Proteins

Question 1

B7

Answer 1

(CD80, CD86)

expressed on: activated APCs

Binds to: CD28 T cell
CTLA-4 inhib receptor

Fxn:
Co-stim (signal 2) for all naive T cell activation
Prevents excessive T-cell effector activity

Question 2

CD19, CD20

Answer 2

Surface marker for B cells (naive and active), plasma cells (CD19 only)

Question 3

CD28

Answer 3

expressed on naive T cell

initiates costimulation survival an anti-anergy “signal 2” when bound to its B7 ligand

Question 4

CD40

Answer 4

Expressed on immature/naive + activated/mature B cells, DC, macs

Initiates costim signal by CD4+ THI CD40L

Deficiency causes Hyper IgM syndroe

Question 5

Fc-gamma receptor

Answer 5

Acts as receptor for Fc stem of Ab expressed on phagocytes, NK cells (CD16)

enables phagocytosis/killing of IgG coated target

Fetal - transports maternal IgG into fetal circulation

Question 6

KIR

Answer 6

NK inhibition
non peptide surfaces of p-MHC I & HLA-G

Dec probability of killing target –> provides missing self recognition paradigm

Question 7

MHC I expressed on ____

Answer 7

all cells

Question 8

MHC II expressed on

Answer 8

Macs
DC
B cells
naive and mature

Question 9

IgM

Answer 9

naive BCR

Major antibody secreted in a primary response

Question 10

Expression of which Ig’s requires class switch recombo?

Answer 10

IgG
IgE
IgA

Occurs in germinal centers

Question 11

Which Ig’s do memory B-cells as their BCRs

Answer 11

IgG
IgA
IgE

Question 12

Normal serum antibody percentages

Answer 12

75% IgG
20% IgA
5% IgM

Question 13

Normal mucosal tissue antibody percentages

Answer 13

80% dimeric IgA
18% IgM
2% IgE

Question 14

HLA-A, B, C

Answer 14

MHC-I

Genes coding for alpha (HC) of MHC )
Will express all alleles of isotypes of MHC-I

Question 15

HLA-DP, DQ, DR

Answer 15

MHC II
Alpha/beta dimers
express all alleles of MHC II
TF needed for expression of all MHC II genes

Question 16

What does deficiency of HLA-DP, DQ, DR cause?

Answer 16

Deficiency prevents CD4 development
—>
SCID

Question 17

CTLA-4

Answer 17

Expressed on activated T-cells
(-) feedback to prevent excessive T cell effector fxn

B7 binds to it to ensure activation occurs w/o excess

Question 18

Which protein class presents endocytosed/phagocytosed proteins?

Answer 18

aka exogenous

MHC Class II

Question 19

Which protein class presents peptides that were synthesized inside the cell?

Answer 19

MHC Class I

Endogenous

Question 20

The primary barrier to allogeneic transplanation is ____

Answer 20

MHC

Question 21

Which complement proteins are important for triggering inflammation?

Answer 21

C3a

C5a

Question 22

Which complement protein triggers the membrane attack complex (MAC)?

Answer 22

C5b
Then C6-C9 join in

Pore leads to death by lysis

Question 23

Which complement protein helps with opsonization?

Answer 23

C3b

Question 24

Which proteins are necessary for the classical pathway to obtain C3 convertase?

Answer 24

C1 binds to
IgG or IgM on cell

C1 then attracts
C2 and C4

Question 25

How do you obtain C3 convertase via the alt pathway

Answer 25

Spont cleavage of C3 | C3b binds to pathogen, then recruits B and D

Question 26

Lectin pathway for C3 convertase

Answer 26

MBL (mannose binding lectin) binds to mannose and then recruits C2 & C4