Micro 2 Lecture 15

Front 1

Immune system specificity:

Back 1

The ability to recognize a pathogen and fight it individually.

Front 2

What are the two different branches of the specific immune system?

Back 2

-The Humoral Immune System (Antibody-Mediated)
-The Cell-Mediated Immune System

Front 3

The Humoral Immune System responses deal with:

Back 3

B-Cells and their eventual production of antibodies.

Front 4

The Cell-Mediated Immune System responses deal with:

Back 4

T-Cells

Front 5

Is there some crossover between the branches?

Back 5

Yes, they are not completely distinct from one another.

Front 6

Define Immunity:

Back 6

The bodies defense against a particular pathogen.

Front 7

Define Cell-Mediated Immunity:

Back 7

Deals with T-Cells

Front 8

Define Humoral Immunity:

Back 8

Deals with B-Cells and their production of antibodies.

Front 9

Define Antigens (Ag):

Back 9

Something that triggers an immune response; whatever is causing the immune system to respond.

Front 10

Define Antibodies (Ab):

Back 10

Proteins made by B-Cells to attack the Antigens.

Front 11

Define Antigenic Determinant (Epitope):

Back 11

The precise part of the Antigen that the Antibody binds to.

Front 12

If the Immune System is responding to a bacterial cell, the entire bacterial cell is the _____________, and the parts on its surface where the antibodies will bind are called _____________.

Back 12

ANTIGEN; ANTIGENIC DETERMINANTS / EPITOPES

Front 13

Where the Antibody attaches to the Antigen is called:

Back 13

The Antigenic Determinant/Epitope.

Front 14

What kind of things can serve as Antigens?

Back 14

Anything; anything that triggers immune response.
-Bacteria
-Viruses
-Foreign human or animal cells
-Pollen or Dust

Front 15

What sorts of structures make good Antigens, ie. stimulate a large immune response?

Back 15

Generally, the LARGER, more COMPLEX the molecule, the stronger the immune response.

Front 16

What sorts of structures make bad Antigens, ie. don't stimulate a large immune response?

Back 16

Smaller molecules or molecules with a repetitive structure.

Front 17

Why do smaller molecules or molecules with a repetitive structure stimulate a smaller immune response?

Back 17

Because there is only one Antigenic Determinant over and over.

Front 18

The importance of having a good Antigen is seen in:

Back 18

Vaccine technology, where it is important to choose a large, complex molecule with lots of Antigenic Determinants on it to stimulate a large immune response and get lots of memory cells from it.

Front 19

Describe the Antibody Structure:

Back 19

The Antibody is made of 4 protein chains:
-2 are identical HEAVY chains (having the same amino acid sequence)
-2 are identical LIGHT chains
The heavy chains are attached together, and the Light chains are attached to the heavy chains.

Front 20

Describe the regions of the Antibody:

Back 20

There are two regions on both the heavy and light chains:
-the Constant region
-the Variable region

Front 21

Describe the Constant region of Antibodies:

Back 21

The constant regions have the exact same amino acid sequence. All Antibodies of the same class have an IDENTICAL constant region.

Front 22

The area at the tip of both the heavy and light chains of the antibody:

Back 22

the Variable region.

Front 23

What does the Variable region determine?

Back 23

The Variable regions controls what the antibody binds to; ie. it's specificity.
-one antibody binds to E. coli and nothing else, another antibody has a different variable region and binds to Salmonella and nothing else.

Front 24

What controls the specificity of antibodies? ie, what the antibody can bind to?

Back 24

The variable regions

Front 25

On the Antibody:
-The top of the Y structure is called:
-The bottom of the Y structure is called:

Back 25

-The top of the Y structure is called: the Antigen Binding Fragment (Fab).
-The bottom of the Y structure is called: the Crystallizable Fragment (Fc).

Front 26

On Antibodies, the binding site for cells is on the:

Back 26

Crystalizable Fragment

Front 27

What are the 5 classes of Antibodies?

Back 27

-IgG
-IgA
-IgM
-IgE
-IgD

Front 28

Antibodies are also called:

Back 28

Immunoglobulins

Front 29

Describe IgG:

Back 29

Exist as Monomers; known for being the Memory Antibody

Front 30

Describe IgA:

Back 30

Exist as Dimers; "the secreted antibody." Found in all body secretions:
-Saliva
-Mucus
-Cervical secretions

Front 31

IgA Dimers are composed of:

Back 31

2 monomers attached together through a protein called the J-chain.

Front 32

What is unique about IgA?

Back 32

It has the Secretory Component; a molecule added in that allows IgA to be secreted in body fluids.

Front 33

Describe IgM:

Back 33

Exist as a Pentamer; five monomers held together via J-chain. The first antibody made during immune response; can serve as B-Cell receptor.

Front 34

Describe IgD:

Back 34

Exists as a monomer; Is the receptor on B-Cells.

Front 35

Which Antibodies are monomers?

Back 35

IgG, IgE, & IgD

Front 36

Which Antibody is the first one made during immune response?

Back 36

IgM

Front 37

Describe the B-Cell receptor:

Back 37

The B-Cell receptor is simply an IgD antibody stuck on its surface.

Front 38

Describe IgE:

Back 38

Exists as monomer; specifically involved in allergy responses.

Front 39

Which antibodies bind to phagocytes?

Back 39

IgA & IgG

Front 40

Which antibodies bind to B-cells?

Back 40

IgM & IgD

Front 41

Which antibodies bind to Mast cells & Basophils?

Back 41

IgE

Front 42

What makes the classes of Antibodies?

Back 42

The Identical amino acid sequences of their Constant regions.

Front 43

Do antibodies of the same class have the same Variable regions?

Back 43

No. ie, one will have Variable regions that will bind to e. coli, while another has Variable regions to bind to Strep pneumoneae. This is what gives them their specificity.

Front 44

What are the antibodies functions?

Back 44

-Compliment Fixation(Classical pathway of triggering complement)
-Agglutination
-Neutralization
-Opsonization

Front 45

Describe Opsonization:

Back 45

The enhancement of phagocytosis by coating the microbe with Compliment proteins or antibodies.

Front 46

Describe Agglutination:

Back 46

The binding of antigens together to deactivate them.

Front 47

Describe compliment fixation:

Back 47

The classical mechanism of triggering Compliment:
-The antibody binds to its antigen triggering the first Compliment protein the the cascade, C1 → Opsonization, Activation of Mast cells (triggering of Inflammation), & Cytolysis by MAC.

Front 48

Describe Neutralization:

Back 48

When Antibodies surround the pathogen so that it can't attach to host tissues. (usually used against viruses)

Front 49

There is a repertoire of __________ in the _________.

Back 49

B CELLS in the LYMPH NODES.

Front 50

The B cell receptor on each B cell is:

Back 50

specific for a particular antigen; each one is different.

Front 51

Define Clonal Selection:

Back 51

When the B cell is activated by the antigen binding to its receptor, endocytosis, & T Helper Cell interaction.

Front 52

What happens after Clonal Selection:

Back 52

Clonal Expansion, the activated B Cell will go through cell division and give rise to two different types of cells: Memory B cells and Plasma cells.

Front 53

What then happens to the Memory B cells and Plasma cells?

Back 53

The Memory B cells hang out in the Lymph Nodes in case of future infection; the Plasma cells secrete antibodies (IgM)

Front 54

Define Clonal Expansion:

Back 54

The process after Clonal Selection where B cell division creates Memory B cells and Plasma cells.

Front 55

After an initial infection, what happens to the Plasma cells that were produced in Clonal Expansion?

Back 55

They die, but the Memory B cells live on in the Lymph Nodes waiting for possible future infection.

Front 56

What is the benefit of the Memory B cell response?

Back 56

It is much faster than the Clonal Selection/ Clonal Expansion process & can flood the body with IgG very quickly in response to infection.

Front 57

The memory response is only seen in the:

Back 57

Specific Immune system.

Front 58

Describe how the B Cell repertoire is made:

Back 58

Front 59

The B cell receptor formed will determine:

Back 59

the antibody made; ie, if the receptor identifies Vibrio cholera, then it will make antibodies against Vibrio cholera.

Front 60

Are all B cells unique in their specificity?

Back 60

yes.

Front 61

How many different possibilities are there in making B cells based on receptors?

Back 61

1.92 Million

Front 62

B Cells mature in the:

Back 62

Bone marrow

Front 63

B Cell maturation is called:

Back 63

Clonal Deletion

Front 64

Describe Clonal Deletion:

Back 64

B Cells are tested to see if they interact with self tissue. Those that do are destroyed, those that pass are sent to the lymph nodes.

Front 65

What are the steps in the life of the B cell:

Back 65

1) Random production of B cell receptors
2) Clonal Deletion
3) Deployment to the Lymph Nodes to await Clonal Selection

Front 66

How are T cells different from B cells?

Back 66

T cells cannot see antigen floating around them like B cells can. They have to have antigen presented to them on Self-MHC.

Front 67

Sometimes in medicine, MHC is called:
-Tissue-typing is called:

Back 67

Human Leukocyte Antigen (HLA)
-HLA typing

Front 68

In tissue typing they are looking at:

Back 68

MHC (HLA), trying to identify how close the donor's MHC is to the recipient.

Front 69

What are the classes of MHC?

Back 69

MHC Class l & MHC Class ll

Front 70

Describe MHC Class l:

Back 70

MHC Class l is made and presented by all cells of the body (except RBCs).

Front 71

Describe MHC Class ll:

Back 71

MHC Class ll is made and presented by professional Antigen Presenting Cells (APCs).

Front 72

What exactly does MHC Class l present?

Back 72

MHC Class l presents intracellular antigens and cellular molecules; takes things from inside the cell and presents it on the surface of the cell.

Front 73

What exactly does MHC Class ll present?

Back 73

MHC Class ll presents bits and pieces of digested FOREIGN antigens.

Front 74

The real self-tag is:

Back 74

MHC Class l

Front 75

What binds to MHC Class l ?

Back 75

Cytotoxic T cells

Front 76

What binds to Class ll MHC?

Back 76

T helper cells

Front 77

Cytotoxic T cells bind to MHC Class __ via:

Back 77

Cytotoxic T cells bind to MHC Class l via their T CELL RECEPTOR & CD8

Front 78

T helper cells bind to MHC Class __ via:

Back 78

T helper cells bind to MHC Class ll via their T CELL RECEPTOR & CD4

Front 79

B cells are:
made in the _____________.
mature in the ____________ .

Back 79

made in the: Bone marrow
mature in the: Bone marrow

Front 80

T cells are:
made in the _____________.
mature in the _____________.

Back 80

made in the: Bone marrow
mature in the: Thymus

Front 81

T cell receptors bind specifically to both:

Back 81

the particular Antigen and self-MHC

Front 82

T cells also have additional receptors called:
These help:

Back 82

Clusters of Differentiation (CD)
These help with the interaction.

Front 83

Cytotoxic T cells = MHC__ & CD__

Back 83

Cytotoxic T cells = MHC l & CD8

Front 84

T helper cells = MHC__ & CD__

Back 84

T helper cells = MHC ll, CD4

Front 85

What are the two main types of T lymphocytes?

Back 85

The T Helper Cells & Cytotoxic T Cells

Front 86

T Helper Cells get activated and differentiate into:

Back 86

Either:
-T helper 1 Cells
-T helper 2 Cells
-CD4+ T Memory Cells

Front 87

Do you get memory cells from all of the specific immune cells?
If so, what are they?

Back 87

Yes, they are:
B Cells= Memory B Cells
T Helper Cells = CD4+ T Memory Cells
Cytotoxic T Cells = CD8+ T Memory Cells

Front 88

What do the T Helper 1 & 2 Cells stimulate?

Back 88

-T helper 1 Cells: Stimulate Macrophages, Cytotoxic Ts, & other T Helper Cells.
-T helper 2 Cells: Stimulate B Cells & Suppress T Helper 1 Cells.

Front 89

What do CD4+ T Memory Cells do?

Back 89

They wait for re-activation upon future infection.

Front 90

What do Cytotoxic T Cells do?

Back 90

They destroy foreign or abnormal cells and give rise to: CD8+ T Memory Cells

Front 91

What do CD8+ T Memory Cells do?

Back 91

They wait for re-activation upon future infection.

Front 92

Describe the T Cell Receptor (TCR):

Back 92

The T Cell Receptor has a Constant Region and a Variable Region.

Front 93

On the T Cell Receptor, what does the Constant Region and Variable Region bind to?

Back 93

The Constant Region binds to: Self-MHC
The Variable Region binds to: the Antigen.

Front 94

How are T Cell Receptors made?

Back 94

The same way that B Cell Receptors & MHC is made, random selection of exons from genes.

Front 95

The maturation process of T Cells occurs in the ________ and is called:

Back 95

Thymus; and is called Positive Selection or Negative Selection.

Front 96

Describe:
-Negative Selection:
-Positive Selection:

Back 96

-Negative Selection: T Cells with useless or dangerous TCRs are destroyed.
-Positive Selection: T Cells with good TCRs are propagated and sent to the lymph nodes and lymphoid tissues.

Front 97

What are the APCs?

Back 97

Macrophages, B Cells, & Dendritic Cells

Front 98

Which APC's main job is to be an APC?

Back 98

the Dendritic Cell.

Front 99

APCs present antigen on:

Back 99

MHC Class ll

Front 100

What is the first step of T Helper Cell Activation?

Back 100

T Cell Receptor with the help of CD4+, binds to the Antigen on MHC Class ll being presented by the APC

Front 101

What is the second step of T Helper Cell Activation?

Back 101

After binding, the APC releases Interleukin-1 or Interleukin-4. The T Helper Cell is now activated and ready to differentiate.

Front 102

If the APC releases IL-1, then the T Helper will differentiate into a:

Back 102

T Helper 1 Cell

Front 103

If the APC releases IL-4, then the T Helper will differentiate into a:

Back 103

T Helper 2 Cell

Front 104

T Helper 1 Cells release ______ which activates:

Back 104

T Helper 1 Cells release IL-2 which activates: Macrophages, Cytotoxic T Cells, & other T Helper Cells.

Front 105

T Helper 2 Cells release ______ which activates:

Back 105

T Helper 2 Cells release IL-4 & B Cell growth factor which activates: B Cells. They also have an inhibitory affect on T Helper 1 Cells.

Front 106

Regardless of IL-1 or IL-4 differentiation, either way, these will be created:

Back 106

CD4+ T Memory Cells

Front 107

If the APC releases IL-1 then:

Back 107

The T Helper Cell differentiates into a T Helper 1 Cell, which releases IL-2 and activates Macrophages, Cytotoxic T Cells, and other T Helper Cells.

Front 108

If the APC releases IL-4 then:

Back 108

The T Helper Cell differentiates into a T Helper 2 Cell, which releases more IL-4 & B Cell Growth Factor which activates B Cells. They also inhibit T Helper 1 Cells.

Front 109

If the APC is a Macrophage or Dendritic cell, then when it interacts with the T Helper Cell it is most likely to release:

Back 109

IL-1

Front 110

If the APC is a B Cell, then when it interacts with the T Helper Cell it is most likely to release:

Back 110

IL-4

Front 111

What exactly do B Cells need to go through clonal expansion?

Back 111

They have to present the Antigen on MHC Class 2 to a T Helper Cell. The B Cell releases IL-4 turning the T Helper Cell into a T Helper 2 Cell. The T Helper 2 Cell then releases more IL-4 and B Cell Growth Factor. The IL-4 & B Cell Growth Factor cause the B Cell to go through Clonal Expansion.

Front 112

Define Cytokines:

Back 112

Chemical messenger molecules that communicate between immune cells.

Front 113

Define Interleukin-1:

Back 113

Activates T Helper Cells to become T Helper 1 Cells when produced by the bound APC.

Front 114

Define Interleukin-2:

Back 114

Produced by active T Helper 1 Cells and stimulates Macrophages, Cytotoxic T Cells, and other T Helper Cells.

Front 115

Define Interleukin-4:

Back 115

Activates T Helper Cells to become T Helper 2 Cells when produced by the bound APC. Also produced by T Helper 2 Cells to help activate B Cells.

Front 116

Define B Cell Growth Factor:

Back 116

Made by T Helper 2 Cells to activate B Cells.

Front 117

Define Interferons:

Back 117

Stimulate production of anti-viral proteins when released by other virally-infected cells.

Front 118

Define Chemokines:

Back 118

Attract leukocytes to an infection when released by Mast Cells.

Front 119

Cytotoxic T Cells bind to antigens presented on:

Back 119

MHC Class l

Front 120

Cytotoxic T Cells are activated by:

Back 120

IL-2 released from T Helper 1 Cells.

Front 121

The active Cytotoxic T Cell releases:

Back 121

Perforins & Granzymes

Front 122

What do Perforins & Granzymes do?

Back 122

Perforins lyze the bound cell & Granzymes degrade cellular proteins.

Front 123

Describe the steps in Cytotoxic T Cell activation:

Back 123

1) Cytotoxic T Cell is activated by IL-2 released from T Helper 1 Cells.
2) Self-Cell presents a piece of Intracellular Antigen on MHC Class 1.
3) Cytotoxic T Cell receptor binds to Antigen & MHC Class 1 with the help of CD8+.
4) Cytotoxic T Cell releases Perforins & Granzymes that destroy the cell.

Front 124

Since T Helper Cells interact with MHC Class ll, they are only activated by:

Back 124

APCs

Front 125

T Helper Cells act as the _____ for the entire immune system.

Back 125

the CONDUCTOR

Front 126

Since Cytotoxic T Cells interact with MHC Class l, they can be activated by:

Back 126

any cell of the body (except RBCs).

Front 127

Which cells target and destroy cells with viral infections and cancerous cells.

Back 127

Cytotoxic T Cells.