Microbiology Exam 3 Immune System - Angie

Front 1

Protection provided by immune responses that mature throughout life; involves B cells and T cells.

Back 1

Adaptive Immunity

Front 2

Y-shaped protein that binds antigen

Back 2

Antibody

Front 3

Molecule that reacts specifically with either an antibody or an antigen receptor on a lymphocyte

Back 3

Antigen

Front 4

A group of white blood cells (leukocytes) that have antigen-specific receptors on their surface; includes B cells and T cells

Back 4

Lymphocyte

Front 5

Antigen-presenting cells: Cells such as B cells, macrophages, and dendritic cells that can present exogenous antigens to naive or memory T cells, activating them

Back 5

APC's

Front 6

Type of lymphocyte programmed to make antibodies

Back 6

B Cells

Front 7

Immunity involving a T-Cell response

Back 7

Cell-Mediated immunity

Front 8

Process in which a lymphocyte's antigen receptor binds to an antigen, allowing the lymphocyte to proliferate

Back 8

Clonal selection

Front 9

Type of lymphocyte programmed to destroy infected or cancerous "self" cells

Back 9

Cytotoxic T Cell

Front 10

Cell type responsible for activating naive T cells

Back 10

Dendritic Cell

Front 11

White blood cells

Back 11

Leukocyte

Front 12

Type of lymphocyte programmed to activate B cells and macrophages, and assist other parts of the adaptive immune response

Back 12

Helper T Cell

Front 13

Immunity involving B cells and an antibody response

Back 13

Humoral immunity

Front 14

Cell surface molecules that present antigen to T cells; includes MHC class I molecules and MHC class II molecules

Back 14

Major Histocompatibility Complex (MHC) Molecules

Front 15

Long-lived descendants of activated lymphocytes that can quickly respond when a specific antigen is encountered again

Back 15

Memory Lymphocytes

Front 16

Effector forms of a B cell; it functions as an antibody-secreting factory

Back 16

Plasma Cell

Front 17

Effector form of a cytotoxic T cell; it induces apoptosis in infected or cancerous "self" cells

Back 17

Tc Cell

Front 18

Effector form of a helper T cell; it activates B cells and macrophages, and releases cytokines that stimulate other parts of the immune system

Back 18

TH cell

Front 19

Host defenses involving anatomical barriers, sensor systems that recognize patterns associated with microbes or tissue damage, phagocytic cells, and the inflammatory response.

Back 19

Innate immunity

Front 20

Programmed death of "self"cells that does not cause inflammation

Back 20

Apoptosis

Front 21

Cell death that does not cause inflammation

Back 21

Apoptosis

Front 22

how long does it take for adaptive immunity to build?

Back 22

A week or more

Front 23

An important characteristic of adaptive immunity. A stronger response to re-exposure.

Back 23

Memory

Front 24

Series of proteins in blood and tissue fluids that can be activated to help destroy and remove invading microbes

Back 24

Complement system

Front 25

Proteins that function as chemical messengers, allowing cells to communicate

Back 25

Cytokines

Front 26

Coordinated innate response with the purpose of containing a site of damage, localizing the response, eliminating the invader and restoring tissue function. The signs of inflammation are swelling, heat, redness, and pain in the infected area.

Back 26

Inflammatory response

Front 27

In which type of immune response does the inflammation process take place?

Back 27

Innate immune response

Front 28

What are the signs of inflammation

Back 28

swelling, heat, redness, and pain in the infected area.

Front 29

Host defenses involving anatomical barriers, sensor systems that recognize patterns associated with microbes or tissue damage, phagocytic cells, and the inflammatory response.

Back 29

Innate immunity

Front 30

Type of phagocytic cell that resides in tissues and has multiple roles, including scavenging debris and producing pro-inflammatory cytokines

Back 30

Macrophage

Front 31

Any group of cytokines that contribute to the inflammatory resonse.

Back 31

Pro-inflammatory cytokines

Front 32

Complement system components that assemble to form pores in membranes of invading cells

Back 32

Membrane Attack Complex (MAC)

Front 33

MAC

Back 33

Membrane Attack Complex

Front 34

Major type of phagocytic cell in blood; neutrophils quickly move to infected tissues to destroy invading microbes.

Back 34

Neutrophil

Front 35

Coating of an object with molecules for which phagocytes have receptors, making it easier for phagocytosis to occur.

Back 35

Opsonization

Front 36

Proteins on or in cells that recognize specific compounds unique to microbes or tissue damage, allowing the cells to sense the presence of invading microbes or damage.

Back 36

Pattern Recognition Receptors (PRR's)

Front 37

PRR

Back 37

Pattern Recognition Receptors

Front 38

Cell type that specializes in engulfing and digesting microbes and cell debris

Back 38

Phagocyte

Front 39

The process by which a phagocyte engulfs an invader

Back 39

Phagocytosis

Front 40

Cells that eat

Back 40

Phagocytes

Front 41

Preventing disease by exposing a person's immune system to harmless forms of the pathogen or its products.

Back 41

Vaccination

Front 42

Why can influenza be contracted repeatedly?

Back 42

The pathogen's ability to continually evade the host defenses.

Front 43

Which immune response has molecular specificity

Back 43

Adaptive immune response

Front 44

The ability to ignore any given molecule

Back 44

tolerance

Front 45

The ability of the immune system to distinguish normal host cells from invading microbes

Back 45

Self versus non-self recognition
or "healthy self" versus "dangerous". Dangerous includes invading microbes as well as cancerous or other "corrupt" cells

Front 46

Why is it important to have cell tolerance?

Back 46

without it the immune system would routinely turn against the body's own cells, attacking them just as it does invading microbes.

Front 47

The primary participants in the adaptive immune responses

Back 47

Lymphocytes

Front 48

First response to a particular antigen

Back 48

Primary response

Front 49

Two basic strategies for countering foreign material used by the adaptive immune system

Back 49

Humoral immunity and cell-mediated immunity (CMI)

Front 50

CMI

Back 50

Cell-mediated immunity

Front 51

Works to eliminate extracellular antigens

Back 51

Humoral immunity

Front 52

Deals with antigens residing within a host cell such as a virus infecting a cell

Back 52

Cell-mediated immunity

Front 53

Other name for B cells

Back 53

B lymphocytes

Front 54

Which cells of the adaptive immune system are responsible for humoral immunity?

Back 54

B cells

Front 55

Where do B cells develop?

Back 55

bone marrow

Front 56

B cells differentiate into what kind of cells?

Back 56

Plasma cells

Front 57

These cells function as factories that produce Y-shaped antigens

Back 57

Plasma cells

Front 58

Y-shaped proteins

Back 58

antibodies

Front 59

Long-lived B cells that respond more quickly if the antigen is encountered again

Back 59

B memory cells

Front 60

How many function regions do antibodies have?

Back 60

Two. The two identical arms and the stem.

Front 61

What are the two regions of antibodies

Back 61

Stem and two identical arms

Front 62

Where is the sequence of amino acids located on an antibody that makes that antibody unique?

Back 62

The end of the arms called the variable region

Front 63

What provides a basis for the specificity of antibodies?

Back 63

The amino acid sequence of the end of the antibody arms or the variable region.

Front 64

Which cells of the adaptive immune system are responsible for humoral immunity?

Back 64

B cells

Front 65

Where do B cells develop?

Back 65

bone marrow

Front 66

B cells differentiate into what kind of cells?

Back 66

Plasma cells

Front 67

These cells function as factories that produce Y-shaped antigens

Back 67

Plasma cells

Front 68

Y-shaped proteins

Back 68

antibodies

Front 69

Long-lived B cells that respond more quickly if the antigen is encountered again

Back 69

B memory cells

Front 70

How many function regions do antibodies have?

Back 70

Two. The two identical arms and the stem.

Front 71

What are the two regions of antibodies

Back 71

Stem and two identical arms

Front 72

Where is the sequence of amino acids located on an antibody that makes that antibody unique?

Back 72

The end of the arms called the variable region

Front 73

What provides a basis for the specificity of antibodies?

Back 73

The amino acid sequence of the end of the antibody arms or the variable region.

Front 74

Give an example of a direct mechanism and an indirect mechanism used by antibodies to protect the host

Back 74

Direct: their ability to bind antigens and coating them, thereby preventing it from attaching to a host cell. An antibody-coated viral particle cannot attach to its receptor, and therefore can not enter the cell.
Indirect: due to the "red flag" region tagging the antigen for elimination.

Front 75

BCR

Back 75

B Cell receptor

Front 76

A membrane-bound version of the specific antibody the B cell is programmed to make

Back 76

BCR B cell receptor

Front 77

What happens if a naive B cell encounters an antigen that its BCR binds? (very next step only)

Back 77

The B cell is triggered to multiply

Front 78

The type of cells involved in Cell-mediated immunity

Back 78

T lymphocytes or T cells

Front 79

Where do T cells mature?

Back 79

Thymus

Front 80

What are the two subsets of T cells?

Back 80

cytotoxic T cells and helper T cells

Front 81

TCR

Back 81

T-cell receptor

Front 82

Surface molecule which allows the cell to bind a specific antigen on T cells

Back 82

TCR T-cell receptor

Front 83

Which receptor, BCR or TCR, recognizes free antigen?

Back 83

BCR only. TCR must recognize an antigen being presented by other cells.

Front 84

What cells are responsible for T-cell activation?

Back 84

Dendritic cells

Front 85

Which type of immunity are dendritic cells technically part of?

Back 85

Innate immunity

Front 86

Effector helper T cells

Back 86

TH cells

Front 87

Effector cytotoxic cells

Back 87

Tc cells

Front 88

Can all three (B cells, TH cells and Tc cells) form memory cells?

Back 88

Yes

Front 89

These cells respond to intracellular antigens

Back 89

Tc Cells

Front 90

What do Tc cells do when an intracellular antigen is recognized in order to protect the host?

Back 90

Tc cells induce the "self" cell that harbors the antigen to undergo apoptosis. Ie viral infected cells.

Front 91

What is one positive side effect of sacrificing host cells which were infected with a virus?

Back 91

Unassembled viral components are released, provoking a humoral response.

Front 92

These cells are programmed to orchestrate the adaptive immune response

Back 92

Helper T cells

Front 93

How is the strategy of the cell-mediated response different from that of the humoral response?

Back 93

Cell-mediated sacrifices a host cell in order to prevent the spread of intracellular antigens. Humoral response involves phagocytizing the antigen.

Front 94

Why is it important that B cells and T cells be activated before they can mount a response against antigen?

Back 94

B cells and T cells can cause damage to host tissues, also they would attack self cells if not activated.

Front 95

How would you expect a Tc cell to respond if it encountered a TH cell that was infected with a virus?

Back 95

The Tc cell would prompt the infected TH cell to undergo apoptosis

Front 96

A collection of tissues and organs that bring the population B cells and T cells into contact with antigens

Back 96

Lymphatic system

Front 97

What is the fluid called in the Lymphatic system?

Back 97

Lymph

Front 98

How is a B-cell receptor similar to an antibody?

Back 98

It is a membrane-bound version of the specific antibody the B cell is programmed to make.

Front 99

Flow within the lymphatic system occurs via the _________.

Back 99

Lymphatic vessels, or lymphatics

Front 100

Explain where lymph fluid comes from.

Back 100

Capillaries filter the blood and supply tissues with the oxygen and nutrients carried by the blood. Most of that fluid then reenters the capillaries, but some enters the lymphatics instead. They lymph - which also contains white blood cells and antigens that have entered the tissues, travels via the lymphatics to the lymph nodes, where proteins, cells, and other materials are removed. The lymph then empties back into the blood circulatory system. Note that the inflammaotry response causes more fluid to enter the tissues at the site of inflammation; this causes a corresponding increase in the antigen-containing fluids that enter the lymph vessels

Front 101

The sites where lymphocytes gather to contact the various antigens

Back 101

Secondary lymphoid organs

Front 102

Give some examples of secondary lymphoid organs

Back 102

lymph nodes, spleen, tonsils, adenoids and appendix

Front 103

Lymph nodes capture materials from ___________ and spleen captures materials from ___________

Back 103

lymphatics; blood

Front 104

__________ capture materials from lymphatics and __________ captures materials from the blood

Back 104

Lymph nodes; spleen

Front 105

The anatomy of the secondary lymphoid organs provides a structured center for various cells of the immune system to interact and transfer _________

Back 105

Cytokines p 358

Front 106

The purpose of the secondary lymphoid organs

Back 106

To capture antigens and bring them into contact with lymphocytes.

Front 107

Where are Peyer's Patches located?

Back 107

Intestinal walls

Front 108

What are Peyer's Patches?

Back 108

Lymphoid tissues located in the intestinal walls that inspect sample of intestinal contents.

Front 109

What kind of epithelial cells transfer material from the intestinal lumen to the Peyer's Patches?

Back 109

M cells

Front 110

a network of lymphoid tissues which includes Peyer's patches?

Back 110

Mucoso-Associated lymphoid tissue (MALT)

Front 111

MALT

Back 111

Mucosa-Associated lymphoid tissue

Front 112

These play a critical role in mucosal immunity (the immune response that prevents microbes from invading the body via mucous membranes

Back 112

MALT

Front 113

The immune response that prevents microbes from invading the body via mucous membranes

Back 113

Mucosal immunity

Front 114

Lymphoid tissues located under the skin

Back 114

SALT Skin-Associated lymphoid tissues

Front 115

SALT

Back 115

Skin-Associated Lymphoid Tissue

Front 116

These lymph organs include the bone marrow and thymus

Back 116

Primary lymphoid organs

Front 117

These cells give rise to all blood cells

Back 117

Hematopoietic stem cells

Front 118

Where do hematopoietic stem cells reside?

Back 118

Bone marrow

Front 119

Where do B cells and T cells originate?

Back 119

Bone marrow

Front 120

Immature T cells migrate to the ________ to mature

Back 120

Thymus

Front 121

Where do immature B cells mature?

Back 121

Bone marrow

Front 122

Where do mature B cells go after the maturation process?

Back 122

Thymus

Front 123

Any molecule that reacts specifically with an antibody, a B-cell receptor, or a T-cell receptor

Back 123

Antibody

Front 124

Referring specifically to an antigen that elicits an immune response in a given situation

Back 124

Immunogen

Front 125

Two general categories of antigens

Back 125

T-dependent antigens,
T-independent antigens

Front 126

If the responding B cell requires assistance from a TH cell, the antigen is _________________

Back 126

T-dependent

Front 127

If the responding B cell does not require assistance from a TH cell, the antigen is _____________

Back 127

T-independent

Front 128

________________ can activate B cells without TH cell help

Back 128

T-independent

Front 129

Examples of T-independent antigens, and why they are T-independent

Back 129

Lipopolysaccharide (LPS) and some carbohydrates. T-independent because of their repeating subunits

Front 130

Various antigens differ in their effectiveness in stimulating an immune respons. __________ generally induce a strong response, wherease ____________ often do not.

Back 130

Proteins, lipids

Front 131

Are antigens generally large or small molecules?

Back 131

Large

Front 132

Antigenic determinants

Back 132

Epitopes

Front 133

How is an epitope different from an antigen?

Back 133

An epitope is a discrete region of the antigen.

Front 134

Would a denatured antigen be expected to have the same epitopes as its native (undenatured) counterpart?

Back 134

No.

Front 135

Antibodies are often called ____________

Back 135

Immunoglobulins

Front 136

Two identical arms of antibodies

Back 136

Fab region
(fragments that are antigen binding)

Front 137

The stem of an antibody

Back 137

Fc region
(fragments that could be crystallized)

Front 138

All antibodies have the same basic Y-shaped structure called the

Back 138

Antibody monomer

Front 139

Two types of antibody chains

Back 139

Heavy chain, made up of heavy molecular weight polypeptides, and Light chain, made up of lower-molecular-weight polypeptide. Light chain makes up the outer part of the Fab region of the antibody

Front 140

How many domains do light chains have?

Back 140

Two each

Front 141

How many domains do heavy chains have?

Back 141

Four each

Front 142

Each light chain is linked to a heavy chain via ___________

Back 142

Disulfide bond

Front 143

One or more ___________ link the two heavy chains at the hinge region of the antibody

Back 143

disulfide bonds

Front 144

The portion at the ends of the Fab region of an antibody

Back 144

Variable region

Front 145

This accounts for the antigen-binding specificity on the antibody

Back 145

Variable region

Front 146

The antigen-binding site on the antibody is located where?

Back 146

At the end of the Fab's variable region between the heavy and light chain

Front 147

The antigen-binding site on an antibody attaches to what?

Back 147

Specific epitope of microorganisms

Front 148

How do antigen-binding sites attach to epitopes?

Back 148

Covalent bonds

Front 149

The constant region of the antibody

Back 149

Fc Region + part of the Fab region. All except the variable region is considered constant

Front 150

Why do we need a constant region of an antibody?

Back 150

Because it provides the body with something steady, consistent and recognizable even with the large number of antibodies present in the body

Front 151

List the five major classes of immunoglobulin

Back 151

IgM, IgG, IgA, IgD and IgE
(GAMED)

Front 152

Immunoglobulin is another name for what?

Back 152

Antigen

Front 153

List six protective outcomes of antibody-antigen binding

Back 153

Neutralization, Opsonization, Complement system activation, Immobilization and adherence, Cross-linking and Antibody-dependent cellular cytotoxicity (ADCC)

Front 154

What is Neutralization in regards to Ab/Ag binding?

Back 154

Coating the toxin or virus with antibodies.

Toxins and viruses must bind specific molecules on a cell surface before they can damage that cell. A toxin or virus coated with antibodies cannot attach to cells and is said to be neutralized.

Front 155

What is Opsonization in regards to Ab/Ag binding?

Back 155

The variable region of an IgG antibody attaches to a microorganism, and the constant region (Fc) sticks out and acts as an opsonin for phagocytes to phagocytize the mo.

Front 156

What kind of antigen is used as an opsonin?

Back 156

IgG

Front 157

What is Complement system activation in regards to Ab/Ag binding?

Back 157

Immune complexes where C1 protein binds and is activated to initiate the complement system.

Front 158

Another name for antigen/antibody complex

Back 158

Immune complex

Front 159

What is Immobilization and prevention of adherence in regards to Ab/Ag binding?

Back 159

Binding of antibodies to flagella interferes with a microbe's ability to move, and binding to pili prevents it from attaching to surfaces. Both can prevent infection.

Front 160

What is Cross-linking in regards to Ab/Ag binding?

Back 160

The two arms of an antibody can bind separate but identical antigen molecules, linking them. The purpose is to create a larger target for phagocytes

Front 161

What is Antibody-dependent cellular cytotoxicity (ADCC) in regards to Ab/Ag binding?

Back 161

When multiple IgG molecules bind to a virally infected cell or a tumor cell, that cell becomes a target for destruction by natural killer cells (NK cells). The NK cell attaches to the Fc regions of IgG and once attached kills the target cell by delivering compounds directly to it.

Front 162

How many immunoglobulin classes are there?

Back 162

5
GAMED

Front 163

The first immunoglobulin class produced during the primary response to an antigen

Back 163

IgM

Front 164

IgM accounts for ________% of the circulating antigens.

Back 164

5%-13%

Front 165

The principle class of immunoglobulin in response to some T-independent antigens

Back 165

IgM

Front 166

Which immunoglobulin is a pentamer?

Back 166

IgM

Front 167

Which immunoglobulin has the primary role of controlling bloodstream infections and why?

Back 167

IgM because its large size prevents it from crossing from the bloodstream into tissues.

Front 168

How many antigen-binding sites does IgM have?

Back 168

10

Front 169

The most efficient class in triggering the classical pathway of complement system activation.

Back 169

IgM

Front 170

Can a fetus make IgM in utero?

Back 170

Yes.

Front 171

IgG accounts for __________% of the total serum immunoglobulin

Back 171

80% - 85%

Front 172

What is serum?

Back 172

the liquid portion of the blood

Front 173

Where is IgG usually?

Back 173

Circulating in the blood but exits the vessels to enter tissues well

Front 174

Which immunoglobulin provides the longest-term protection of any antibody class?

Back 174

IgG

Front 175

What is the half life of IgG?

Back 175

21 days
Meaning that a given number of IgG molecules will be reduced by about 50% after 21 days.

Front 176

What is the first and most abundant circulating class produced during the secondary response?

Back 176

IgG Class

Front 177

Which immunoglobulin provides protection by means of all six mechanisms?

Back 177

IgG
neutralization, opsonization, complement activation, immobilization and prevention of adherence, cross-linking and ADCC.

Front 178

Which immunoglobulin is transported across the placenta into the fetus' bloodstream?

Back 178

IgG

Front 179

Which immunoglobulins protect the newborn?

Back 179

Maternal IgG from in utero, IgG and IgA from breast milk.
IgG is in colostrum, IgA is in breast milk after colostrum as well.

Front 180

How long is a newborn protected by maternal antibodies?

Back 180

Approximately 6 months

Front 181

What is colostrum?

Back 181

First breast milk produced after giving birth.

Front 182

IgA accounts for ________% of antibodies in the serum.

Back 182

10%-13%

Front 183

What is the half life of IgM?

Back 183

10 days

Front 184

What is the half life of IgG?

Back 184

21 days

Front 185

What is the half life of IgA?

Back 185

6 days

Front 186

What is the half life of IgD?

Back 186

3 days

Front 187

What is the half life of IgE?

Back 187

2 days

Front 188

The most abundant immunoglobulin produced (not just in serum)

Back 188

IgA
It's present in mucus.

Front 189

The dimer of this immunoglobulin is found on the mucous membranes.

Back 189

IgA

Front 190

The secreted form of this immunoglobulin is found in gastrointestinal, genitourinary and respiratory tracts.

Back 190

IgA

Front 191

This immunoglobulin is found in secretions such as saliva, tears and breast milk.

Back 191

IgA

Front 192

What mechanisms does IgA utilize to protect the host?

Back 192

Neutralization, interfering with attachment of microbes to host cells.

Front 193

How and where is IgA produced?

Back 193

In the plasma cells located in mucosa-associated lymphoid tissues (MALT).

Front 194

How is IgA protected from enzymes on the mucosal surface?

Back 194

A polypeptide called the secretory component is attached to IgA as IgA is transported across the mucosa.

Front 195

IgD accounts for _______% of immunoglobulin in the serum

Back 195

<1%

Front 196

Which immunoglobulin's functions are not very well defined?

Back 196

IgD

Front 197

IgE accounts for ________% of immunoglobulin in the serum

Back 197

<0.01%, IgE is barely detectable in blood

Front 198

Why is IgE barely detectable in the serum?

Back 198

It is the most tightly bound by the FC region to basophils and mast cells rather than being free in circulation.

Front 199

Bound _________ allows mast cells and basophils to detect and respond to antigens.

Back 199

IgE

Front 200

When antigen binds to two adjacent IgE molecules on a mast cell or basophil _______ is released by the mast cell or basophil.

Back 200

Histamine and other inflammatory mediators

Front 201

_________ - mediated responses are important in eliminating parasites, particularly helminths

Back 201

IgE

Front 202

_______ and ________ release their chemicals when IgE binds to normally harmless materials such as foods, dust and pollens

Back 202

Basophils and mast cells.
this is called hypersensitivity reaction.

Front 203

Pneumonic for the six mechanisms of function of immunoglobulins.

Back 203

INOCCA
Immobilization and prevention of adherence
Neutralization
Opsonization
Complement system activation
Cross-linking
Antibody-dependent cellular cytotoxicity (ADCC)

Front 204

Why is IgM particularly effect at cross-linking antigens?

Back 204

It is a pentamer and has 10 linking sites and can link 10 microbes at once.

Front 205

Which maternal antibody classes protect a breast-fed newborn?

Back 205

IgG and IgA

Front 206

In opsonization with IgG, why is it important that phagocytes recognize the antibodies only after they bind antigen?

Back 206

Phagocytes could phagocytize just the antibodies before they have attached to anything.

Front 207

Does clonal selection pertain to both B cells and T cells?

Back 207

Yes

Front 208

These lymphocytes have not fully developed their antigen-specific receptors

Back 208

Immature lymphocytes

Front 209

These lymphocytes have antigen receptors, but have not yet encountered the antigen to which they are programmed to respond

Back 209

Naive lymphocytes

Front 210

These lymphocytes are able to proliferate; they have bound antigen via their antigen receptor and have received he required accessory signals from another cell, confirming that the antigen merits response

Back 210

Activated lymphocyte

Front 211

These lymphocytes are descendants of activated lymphocytes, armed with the ability to produce specific cytokines or other protective substances.

Back 211

Effector lymphocytes
p. 363
Plasma cells are effector B cells, Tc cells are effector cytotoxic T cells, and TH cells are effector T helper cells.

Front 212

These lymphocytes are long-lived descendants of activated lymphocytes; they can quickly become activated when an antigen is encountered again. They are responsible for the speed and effectiveness of the secondary response.

Back 212

Memory lymphocytes

Front 213

Describe the clonal selection theory.

Back 213

The process by which the binding of an B cell receptor to an antigen activates that B cell and allows it to differentiate into memory B cells and plasma cells which create antibodies for the antigen and release the into the system.

Front 214

How does a naive lymphocyte differ from an activated one?

Back 214

Naive has never bound antigen. Activated has bound antigen.

Front 215

If the heavy chain of an antibody is approx. 450 amino acids long, how much DNA would be required to encode 10^9 separate heavy chain genes?

Back 215

3 x 10^9 because an amino acid is 3 a nucleotide sequence

Front 216

The process in which a B cell takes in an antigen when it encounters it

Back 216

Endocytosis

Front 217

What is endocytosis?

Back 217

The process by which cells bring molecules into it by engulfing it with cell membrane and pinching it off from the outer environment.

Front 218

MHC Class II molecules

Back 218

Major-histocompatibility molecules. Proteins on the surface of B cells which bind with peptide fragments of a mo the cell had bound to. They present the mo to Th cells.

Front 219

MHC Class I molecules

Back 219

Major-histocompatability complex on the surface of cells used to present antigen to cytotoxic T cells

Front 220

How do Th cells activate B cells when they recognize an antigen the B cell is presenting?

Back 220

By releasing cytokines.

Front 221

What is anergic?

Back 221

unresponsive to future exposure to the antigen, resulting in tolerance to that antigen.

Front 222

What happens if no TH cells recognize the antigen presented by the B cell?

Back 222

The B cell becomes anergic to the antigen, meaning it becomes tolerant of it. This is an important process of being tolerant of self and harmless antigens.

Front 223

A form of natural selection among proliferating B cells

Back 223

Affinity maturation

Front 224

What accounts for the change in a B cell's ability to bind antigen?

Back 224

Affinity maturation

Front 225

All B cells are initially programmed to differentiate into plasma cells that secret ______ immunoglobulin.

Back 225

IgM

Front 226

If class switching occurs in Peyer's patches, which immunoglobulin will likely be the end result?

Back 226

IgA.
Peyer's patches are part of the system in which IgA is most abundant

Front 227

The ___________ response is significantly faster and more effective than the ___________ response

Back 227

secondary; primary

Front 228

______________ are responsible for the efficiency of the secondary response

Back 228

Memory B cells

Front 229

___________ can activate B cells without the aid of TH cells

Back 229

T-independent antigens

Front 230

Affinity maturation and class switching occur in the ________ (primary/secondary) response?

Back 230

Primary response

Front 231

Do T cells ever produce antibodies?

Back 231

No

Front 232

What is the difference between a B cell receptor and a T cell receptor (structure)

Back 232

B cell receptor is a membrane bound version of the antibodies that B cell is programmed to make. Its structure is identical to the antibodies.
T cell receptor has either alpha/beta or gamma/delta polypeptide chains, each with a variable and a constant region.

Front 233

How do T cell receptors interact with antigen?

Back 233

Must be presented by another host cell

Front 234

A T cell receptor is similar to which part of a B cell receptor?

Back 234

One arm of the B cell receptor

Front 235

MHC Class _____ present endogenous antigens and MHC Clsss _____ present exogenous antigens

Back 235

I, II

Front 236

Describe endogenous and exogenous antigens

Back 236

Endogenous antigens are made within the cell (viral particles) and exogenous have been taken up by the cell (B cell)

Front 237

What kind of cells produce Class I MHC?

Back 237

Nucleated cells

Front 238

What kind of cells produce Class II MHC?

Back 238

Antigen presenting cells (APC's) such as B cells, macrophages, dendritic cells.

Front 239

_______ T cells recognize MHC Class I molecules

Back 239

Tc Cells

Front 240

_______T cells recognize MHC Class II molecules

Back 240

TH cells

Front 241

How do scientists distinguish cytotoxic and helper T cells since they are identically microscopically?

Back 241

CD Markers
Cluster of differentiation markers which are proteins on the cells.

Front 242

Most cytotoxic T cells have _____ marker.

Back 242

CD8

Front 243

Most helper T cells have _____ marker.

Back 243

CD4

Front 244

Which CD marker is a receptor for HIV?

Back 244

CD4, which is why helper T cells are the target for HIV

Front 245

What is the fate of a cell that presents antigen recognized by a Tc cell?

Back 245

The cell will be prompted by cytotoxins released by the Tc cell to undergo apoptosis.

Front 246

What is the fate of a cell that presents antigen recognized by a TH cell?

Back 246

The presenting cell will become activated and multiply.

Front 247

The scouts of innate immunity

Back 247

Dendritic cells

Front 248

______ cells play a crucial role in T cell activation

Back 248

Dendritic cells

Front 249

How do dendritic cells gather material from the respiratory tract and the lumen of the intestine?

Back 249

By sending tentacle-like extensions between the epithelial cells of the barriers.

Front 250

What kind of receptors do dendritic cells have?

Back 250

Toll like receptors and others

Front 251

What does a dendritic cell do after it recognizes a pathogen?

Back 251

Travels to the secondary lymphoid organs where it will encounter naive T cells

Front 252

What kind of cells do dendritic cells interact with in the secondary lymphoid tissues?

Back 252

Naive T cells

Front 253

Dendritic cells are naive until they mature when?

Back 253

En route to the secondary lymphoid organs.

Front 254

Dendritic cells that detected pathogens produce surface proteins called __________.

Back 254

Co-stimulatory molecules

Front 255

What two things must be present for a naive T cell to become activated?

Back 255

Antigen recognition and the dendritic cell must be presenting co-stimulatory molecules.

Front 256

What happens to a naive T call that recognizes antigen being displayed by dendritic cells but there are no co-stimulatory molecules present?

Back 256

The naive T cell becomes anergic, which means it has a tolerance to that antigen. The antigen could be a self antigen or is simply just not harmful. The t cell will eventually undergo apoptosis.

Front 257

What kind of molecules (class I or class II) do dendritic cells present peptides on?

Back 257

Both class I and class II, called cross presentation

Front 258

What is meant by "cross present"

Back 258

The ability of a (dendritic) cell to present peptide on both class I and class II MHC molecules

Front 259

Cross presentation by dendritic cells allows activation of which type of T cell?

Back 259

Both cytotoxic T cells and helper T cells.

Front 260

Tc Cells expose target cells to these two things in order to initiate target cell apoptosis?

Back 260

Perforin (a molecule that forms pores in the cell membrane) and several proteases (cause reactions from within the cell which trigger apoptosis)

Front 261

What is perforin?

Back 261

A cytotoxin which forms pores in a cell membrane, particularly a cell targeted by a Tc cell for apoptosis.

Front 262

What is a death receptor?

Back 262

A receptor on a self cell which can be engaged by a specific molecule on Tc Cells to initiate self cell apoptosis.

Front 263

Why is it more beneficial to kill a target cell by means of apoptosis rather than cell lysis?

Back 263

It minimizes the number of intracellular microbes that might spill into the surrounding area and infect other cells.

Front 264

Does a Tc cell die after it affects a target self cell?

Back 264

No, it can go on to kill other targets.

Front 265

What are the functions of two cytokines released into the environment after a Tc cell initiates apoptosis of an infected self cell?

Back 265

One cytokine stimulates antigen processing and presentation in neighboring cells, causing them to present more antigen on their surfaces which makes it easier for other Tc cells to find them and see if they were also infected.
Another cytokine activates local macrophages whose TLR's have been triggered. Macrophages will come phagocytize the dead self cell.

Front 266

_______ cells orchestrate the immune response

Back 266

TH cells

Front 267

How do TH cells orchestrate the immune response?

Back 267

They activate B cells and macrophages, and direct the activity of B cells, macrophages and T cells.

Front 268

Describe how a conjugate vaccine works and why it is needed.

Back 268

Ie meningitis in small children
Meningitis is surrounded by a capsule made of a polypeptide chain, which is a T-independent antigen. Small children do not deal with T-independent antigens so by covalently attaching a large protein to the meningitis molecule. the polysaccharide component binds to a B cell receptor and the entire molecule is taken in. Because the B cell will present some of the protein component, the TH cells will recognize it and induce a better immune response.

Front 269

A molecule that binds B cell receptor yet does not normally elicit antibody production

Back 269

Hapten

Front 270

Why would TH cells activate macrophages?

Back 270

If the macrophage can't control an invader by phagocytosis, a TH cell can activate it, allowing it to produce more potent destructive mechanisms.

Front 271

What physical changes does a macrophage undergo once it is activated?

Back 271

It becomes larger, the plasma membrane becomes ruffled and irregular, and the cell increases its metabolism so lysosomes increase in number, produces nitric oxide.

Front 272

If activated macrophage response is still not sufficient, macrophages fuse together to form ________.

Back 272

Giant cells

Front 273

What are giant cells?

Back 273

Macrophages fused together that work with other macrophages and T cells and form granulomas that wall off the offending agent, preventing offending microbes from escaping and infecting other cells.

Front 274

What kind of organism can survive within a macrophage?

Back 274

Tuberculosis

Front 275

If tuberculosis survives phagocytosis, what is the back up plan?

Back 275

TH cells activate the macrophage to release more potent reactions.

Front 276

Name three types of antigen-presenting cells.

Back 276

B cells, macrophages and dendritic cells

Front 277

If an effector CD8 cell recognizes antigen presented on an MHC class I molecule, how should it respond?

Back 277

By releasing cytokines which induce cell apoptosis, as well as cytokines which increase antigen recognition and presentation in neighboring cells.

Front 278

Why would a person who has AIDS be more susceptible to the bacterium that causes tuberculosis?

Back 278

TH cells are invaded and killed by the AIDS virus, and TH cells are required when a macrophage attempts and fails to phagocytize tuberculosis because the tuberculosis is not degraded by phagocytosis. In this case a TH cell would activate the macrophage allowing it to produce more powerful means to kill the tuberculosis.

Front 279

What is the mechanism used by Natural Killer cells to kill antibody-bound cells?

Back 279

Antibody-dependent cellular toxicity

Front 280

Some viruses have adapted to prevent a cell from producing MHC Class I molecules. How are these cells managed?

Back 280

Natural killer cells recognize a cell's lack of MHC Class I molecules on its surface along with other signals that the cell is under stress, and initiate apoptosis.

Front 281

Why would a self cell not display a MHC Class I molecule?

Back 281

A virus may have adapted to prevent the cell from producing MHC Class I molecules in an effort to prevent Tc Cells from initiating apoptosis on the cell.

Front 282

Why might a virus encode its own version of an MHC Class I molecule?

Back 282

Because at least there will be some version of the MHC molecule on the cell surface which would trick the natural killer cells into not initiating apoptosis due to the cell's lack of MHC Class I surface molecules.