Chapter 13: Host Defenses Adaptive Immunity- Part 2

Question 1

Biological function of IgG

Answer 1

Produced by plasma cells in a primary response and by memory cells responding the second time to a given antigenic stimulus

Question 2

What is the most prevalent antibody circulating through the tissue fluids and blood?

Answer 2

IgG (neutralizes toxins, opsonizes, fixes complement

Question 3

IgA function (Dimer and monomer)

Answer 3

Dimer is secretory antibody on mucous membrane, monomer in small quantities in blood (found a lot in GI tract)

Question 4

IgM biological function

Answer 4

Produced at first response to antigen, can serve as B cell receptor

Question 5

IgD biological function

Answer 5

Receptor on B cells; triggering molecule for B cell activation

Question 6

IgE biological function

Answer 6

Antibody of allergy, woes infection, mediates anaphylaxis, asthma, etc

Question 7

Which antibody class crosses placenta?

Answer 7

IgG

Question 8

Fc region of IgG binds to..

Answer 8

Phagocytes

Question 9

Fc region of IgE binds to..

Answer 9

Mast cells and basophils

Question 10

___ and ___ can tell you when someone was exposed to something

Answer 10

IgM

IgG

Question 11

Effects of antibody binding to antigen (6)

Answer 11

1. Neutralization
2. Immobilization and preventing adherence
3. Agglutination and precipitation
4. Opsinization facilitates phagocytosis
5. Complement system activation
6. Antibody-dependednt cell cytotoxicity (ADCC)

Question 12

Neutralization

Answer 12

Blocks the biologically relevant portion of an antigen, rendering it inactive

Question 13

Opsonization

Answer 13

A process that makes microbes more readily recognized by phagocytes

Question 14

Each genetically unique line of lymphocytes arising from extensive recombinations of surface proteins is termed a _______

Answer 14

Clone

Question 15

Immune tolerance

Answer 15

Where any lymphocytes that develop a specificity for self molecules and could be harmful are eliminated from the pool of cells.

Question 16

After a B cell is activated it can go through..

Answer 16

• Class-switching to other classes
• Affinity maturation
• Generation of memory B cells

Question 17

Affinity maturation

Answer 17

Programmed mutations of antibody variable genes

Question 18

Affinity maturation: most mutations result in a _______ or ___ change in affinity of BCR

Answer 18

Decrease

No

Question 19

Affinity maturation: some mutations result in a higher affinity BCR and these ____ _______ B cells with lower affinity

Answer 19

Out compete

Question 20

The three events that follow B cell activation require what?

Answer 20

T cell help

Question 21

Titer

Answer 21

Concentration of antibodies in a serum measured over a time period

Question 22

Can T cells bind to Ag on their own?

Answer 22

No, they must be “shown” antigen by antigen presenting cell

Question 23

Helper T cells respond to…

Answer 23

Extracellular antigen

Question 24

Extracellular antigen is captured and processed by a _______ ______ _______ ____ and shown to the Th cell

Answer 24

Professional antigen presenting cell (PAPC)

Question 25

Professional antigen presenting cells

Answer 25

Dendritic cells
Macrophages
B cells

Question 26

The PAPC places the antigen on ____ __ receptors and presents them on the _____ of the cell

Answer 26

MHC II

Surface

Question 27

After the antigen is placed on the surface of a PAPC, what happens?

Answer 27

The Th cell with a T cell receptor capable of recognizing the antigen will bind and b become activated

Question 28

The PAPC provides a second signal to allow the Th cell to…

Answer 28

Fully activate

Question 29

Cytotoxic T cells respond to…

Answer 29

Intracellular antigens

Question 30

What cells can present antigen to Tc (cytotoxic) cell?

Answer 30

Any cell of the body that is nucleated

Question 31

First step in cytotoxic T cell activation

Answer 31

Intracellular antigen is processed by infected cell and placed on MHC I receptor for presentation to Tc cell

Question 32

After an antigen is placed on the surface, what happens in cytotoxic T cell activation?

Answer 32

The Tc cell with a T cell receptor capable of recognizing the antigen will bind and start to become activated

Question 33

What must Tc cells receive in order to fully activate?

Answer 33

A secondary signal (Th cells secrete cytokines which provide a chemical signal to activate)

Question 34

Two signals needed for full activation of a cytotoxic T cell

Answer 34

1. Recognize Ag that is attached to MHC I using TCR and CD8 receptor
2. Cytokine signal from a helper T cell

Question 35

What do Cytotoxic T cells do when when it recognizes an infected “self” cell?

Answer 35

Delivers preformed cytotoxins to the infected cell and produces cytokines that allows neighboring cells to become more vigilant against intracellular pathogens

Question 36

Two signals needed for Helper T cell activation

Answer 36

1. Recognize Ag that is attached to MHC II using TCR and CD4 coreceptor
2. . Costimulation from receptors on the surface of the PAPC

Question 37

When a macrophage engulfs materials, what happens next? (Helper T cell activation)

Answer 37

Macrophage degrades proteins in phagosome into peptide fragments

Question 38

What happens once a helper T cell is activated?

Answer 38

Activation of the macrophage (targeted delivery of cytotoxins activate the macrophage)