Immuno Lecture 4 Antigen Recognition

Front 1

Signaling functions of antibody immune response are mediated by

Back 1

Ig-alpha and Ig-beta associated with membrane bound Ig

Front 2

Signaling functions of TCR immune response are mediated by

Back 2

CD3 and ζ-chain (zeta chain)

Front 3

At the _____________ end of each IgH and IgL chain is a region that differs in sequence in different antibody molecules called the ___________

Back 3

At the amino terminal end of each IgH and IgL chain is a region that differs in sequence in different antibody molecules called the variable region

Front 4

Hinge Region?

Back 4

region where each heavy chain is covalently linked

Front 5

Effector functions:
IgA =
IgD =
IgE =
IgG =
IgM =

Back 5

IgA = Mucosal immunity

IgD = Naive b-cell antigen receptor

IgE = Mast cell activation (allergy), defense against helminthic parasites (worms)

IgG = Compliment activation, neonatal immunity, opsonization, ADCC

IgM = Expressed on naive B cells, first antibody made during immune response, complement activation

Front 6

hypervariable regions are responsible for ___________ and are known as ?

Back 6

hypervariable regions are responsible for antigen recognition and are known as complementarity-determining regions (CDRs): CDR1, CDR2 & CDR3

Front 7

_________ are primarily responsible for interacting with MHC molecules, whereas ______ is responsible for interacting with peptide antigen.

Back 7

CDR1 & CDR2 are primarily responsible for interacting with MHC molecules, whereas CDR3 is responsible for interacting with peptide antigen.

Front 8

Only _____ contacts antigen in TCR. What about B-cell?

Back 8

Only CDR3 contacts antigen in TCR

all 3 contact antigen in Bcell

Front 9

The lymphocyte specific proteins that control recombination are known as ?

Back 9

recombinase activating gene 1(RAG1) and recombinase activating gene 2 (RAG2)

Front 10

Can you survive with just one of the RAGs?

Back 10

no

Front 11

Rearrangement of B-cell heavy chain?

Back 11

D to a J = DJ

followed by

V to a DJ = VDJ

Front 12

AFTER V and DJ rearrangements what happens?

Back 12

mRNA is produced and constant region is spliced to VDJ

Front 13

In terms of VDJ segments on heavy chain, where are the CDR locations?

Back 13

CDR 1 and CDR 2 = V

CDR 3 = VD and J (all 3)

Front 14

In terms of VJ segments on light chain, where are the CDR locations?

Back 14

CDCDR 1 and CDR 2 = V

CDR 3 = V and J (both)

Front 15

What is the biggest source of B and T cell diversity?

Back 15

junctional diversity - the regions connecting the D to J and V to DJ

Front 16

Two types of junctional diversity? which one contributes most to junctional diversity?

Back 16

P nucleotides and N-nucleotides

N-nucleotides contribute most to diversity

Front 17

P-nucleotides?

Back 17

DNA polymerase extension of short ends

Front 18

N-nucleotides?

Back 18

terminal deoxynucleotidyl-transferase (TdT) addition of nucleotides

Front 19

Allelic exclusion?

Back 19

inhibition of other rearrangements once a successful heavy and/or light chain rearrangement has occured

Front 20

Positive selection?

Back 20

Only Double Positive thymocytes which express a TCR which can recognize peptide in the context of self-MHC are allowed to proceed in development.

Lack of positive selection = apoptotic death

Front 21

Negative Selection?

Back 21

DP thymocytes which express a TCR which can recognize peptide in the context of self-MHC with high affinity die by apoptosis.