Lecture 11

Question 1

Types of specific Immunity.

Answer 1

1. naturally acquired active: host develops after foreign substance exposure
2. naturally acquired passive: transfer of Ab
3. artificially acquired active: vaccination
4. Artificially acquired passive: Ab formed by another host transferred to another.

Question 2

Affinity

Answer 2

strength of which the antibody binds to the antigen at the proper site

Question 3

Avidity

Answer 3

overall strength of the Ag-Ab binding. based on affinity and number of sites that are bound

Question 4

Hapten

Answer 4

Ag that is super small, and combined with carrier molecules to act as an Ag

Question 5

What cells are lacking MHC I?

Answer 5

RBC, cancer, virally infected cells

Question 6

Endogenous Ag processing

Answer 6

consists of MHC I binding and presenting to CD8+ T cells

Question 7

Exogenous Ag processing

Answer 7

consists of MHC II binding and presenting Ag fragments from the outside of the cell to CD4+ T cells

Question 8

Antigen Presenting Cells (APC)

Answer 8

B cell, Dendritic cells, Activated macrophages

Question 9

Natural killer cells have what function?

Answer 9

kill virus infected cells and tumor cells, attack parasites

Question 10

What is a Th0 cell?

Answer 10

undifferentiated T cell

Question 11

What is a Th1 cell?

Answer 11

helper cell that activates macrophages

Question 12

What is a Th2 cell?

Answer 12

helps B cells to produce antibodies

Question 13

What is a Th17 cell?

Answer 13

aid with microbial response; inflammation response

Question 14

What is a Treg cell?

Answer 14

This cell aids with controlling the immune response; prevents a cytokine storm, or overactivation which would be deleterious to the self.

Question 15

What do Th1 cells do?

Answer 15

promote Tc and activate macrophages.

- secrete IFN-gamma, IL-2, TNF-beta

Question 16

What do Th2 cells do and secrete?

Answer 16

1. stimulate antibody resposne; defend against helminths
2. promote allergic reaction
3. secrete IL-5,-6,-10,-13

Question 17

When does a CD8+ T cell kill the target cell?

Answer 17

binds to target then activates perforin and CD95 pathway to cause lysis to the target cell.

Question 18

What are the two signals that are required for T cell activation?

Answer 18

1. TCR/MHC initiates the signaling cascade of membrane and intracellular molecules
2. second signal activates proliferation, differentiation, gene expression of genes unique to the required response

Question 19

What is teh function of Treg cells?

Answer 19

1. suppress function of IL-9, TGF-beta
2. IL-10 inhibits Th cell function
3. Foxp3 upregulates CD25/CTLA-4 which are inhibitory signal receptors

Question 20

What can be a superantigen?

Answer 20

bacterial or viral proteins

Question 21

What are the effects of superantigen binding?

Answer 21

1. nonspecific T cell activation
2. massive, rapid release of cytokines
3. cytokine storm, do not bind at the CDR3 domain like other Ag.

Question 22

What two ways can B cells be activated?

Answer 22

1. T cell dependent

2. T cell independent

Question 23

What two signals are required for T cell dependent antigen activation?

Answer 23

1. Ag-BCR complex binding
2. Th2 cell binds with B cells’ Ag to secrete cytokines
   - similar to T cells binding (2 signals at minimum)

Question 24

What are the effects of B cells being activated by T cell?

Answer 24

1. differentiation in to plasma cells or memory cells

Question 25

What are the effects of T independent antigen activation?

Answer 25

1. less effective than T cell dependent 2. low affinity for Ag 3. no memory B cells form 4. bind to large number of epitopes

Question 26

Features of IgG

Answer 26

1. monomer 2. fix complement 3. blood, lymph, intestine 4. enhance phagocytosis, neutralize toxins, protects fetus/newborn

Question 27

Features of IgM

Answer 27

1. fix complement 2. blood, lymph, B cells 3. agglutinate microbe, 1st Ag produced in infection.

Question 28

Features of IgA

Answer 28

1. dimer. secretory is slgA 2. in secretions 3. mucosal protection

Question 29

Features of IgD

Answer 29

1. monomer 2. blood, lymph, B cells 3. initiate immune response

Question 30

Features of IgE

Answer 30

1. on mast cells, basophils, blood 2. provide opsonization 3. allergic reactions, lyse helminths (parasitic worm)

Question 31

What is generally secreted before and after activation of B cells?

Answer 31

before: monomeric IgM after: pentameric IgM

Question 32

What is an antibody titer?

Answer 32

1. measure of serum antibody concentration | 2. represents the lowest amount of antiserum that can be measured

Question 33

What is unique about a second immune response, which utilizes memory cell?

Answer 33

1. shorter lag phase 2. more rapid log phase 3. longer persistence 4. higher IgG titer and Ab have higher affinity for Ag

Question 34

What contributes to Ab diversity?

Answer 34

1. combinatorial joining; junctional joining 2. alternate splicing of mRNA 3. somatic mutation

Question 35

What is unique about combinatorial joining?

Answer 35

1. segments are clustered separately on same chromosomes 2. RAG-1,-2 enzymes are required 3. heavy and light chain specific

Question 36

What can somatic mutation cause, and where will they most likely happen?

Answer 36

1. produce Ab with different epitopes 2. therefore will occur on V regions * high rate of somatic mutation with Ag challenge

Question 37

What is a hybridoma?

Answer 37

monoclonal antibody

Question 38

What are monoclonal antibodies, such as hybridomas, potentially going to be used for?

Answer 38

1. overcome limitations of antisera | 2. used to produce monoclonal Ab that recognize one epitope

Question 39

What are the effects of Ab-Ag binding?

Answer 39

1. agglutination 2. opsonization 3. complement activation 4. neutralization 5. antibody dependent cell-mediated cytotoxicity

Question 40

What is agglutination?

Answer 40

1. Ag-Ab binding effect | 2. grouping of bacteria to localized areas

Question 41

What is opsonization?

Answer 41

1. Ag-Ab binding effect | 2. coating of Ag with Ab to enhance phagocytosis