BSI 2 Lecture 8-10: Immunology

Question 1

What is responsible for the specificity of the acquired immune response?

Answer 1

Specific antigens

Question 2

What allows the body to generate immunity against invading bacteria, viruses, toxins, and foreign tissues?

Answer 2

Lymphocytes

Question 3

How do lymphocytes generate immunity?

Answer 3

1) Produce specific antibodies

2) attack and destroy the invader

Question 4

What type of lymphocytes produce a humoral response by synthesizing circulating antibodies that target the invader for destruction?

Answer 4

B-lymphocytes

Question 5

What type of lymphocytes produce activated “killer cells” that directly destroy the invaders?

Answer 5

T-lymphocytes

Question 6

What are antigens recognized by?

Answer 6

Immunoglobulins (antibodies)

Question 7

The different blood group antigens (A and B), are due to different ___________ on a surface glycoprotein.

Answer 7

Sugar residues

Question 8

What do T-lymphocytes need to activate them specifically?

Answer 8

Antigen Presenting Cells

Question 9

Define: Antigens

Answer 9

Molecules that are identified as foreign and produce an immune response

Question 10

What is the name for the repeating/reoccurring molecular groups?

Answer 10

Epitopes

Question 11

Where are B-cells produced?

Answer 11

Prior to birth they are processed in the liver, after birth they are made in the bone marrow

Question 12

Where are lymphocytes activated?

Answer 12

In peripheral lymphoid organs

Question 13

What are the functions of B-cells?

Answer 13

1) Initiate antibody-mediated immune responses
2) Transform into plasma cells, which secrete antibodies
3) Present antigens to helper T cells

Question 14

What is the function of a cytotoxic T cell (CD8 cells)?

Answer 14

Bind to antigens on plasma membrane of target cells and directly destroy the cells

Question 15

What is the function of Helper T cells (CD4 cells)?

Answer 15

Secrete cytokines that help to activate B cells, T cells, NK cells, and macrophages

Question 16

What are the functions of NK cells?

Answer 16

1) Bind directly and nonspecifically to virus-infected cells and kill them
2) Function as killer cells in antibody-dependent cellular cytotoxicity

Question 17

Where are Plasma cells produced?

Answer 17

In peripheral lymphoid organs; differentiate from B cells during immune responses

Question 18

What is the function of plasma cells?

Answer 18

To secrete antibodies

Question 19

Can B-cells produce antibodies?

Answer 19

No, they have to transform into plasma cells in order to secrete antibodies

Question 20

What type of cell can’t present a recognition to the a cytotoxic T cell?

Answer 20

Red blood cells

Question 21

What is the power house of acquired immunity?

Answer 21

Lymphocytes

Question 22

What filters the lymph?

Answer 22

Lymphnodes

Question 23

What filters blood?

Answer 23

Spleen, thymus, bone marrow, and liver

Question 24

What are the two types of lymphocytes?

Answer 24

B-lymphocytes and T-lymphocytes

Question 25

Where do these lymphocytes derive from?

Answer 25

Pluripotent hematopoietic stem cells

Question 26

Where do nearly all lymphocytes reside?

Answer 26

In lymphoid tissues

Question 27

Where do potential T-lymphocytes first migrate?

Answer 27

Thymus

Question 28

Where are B-lymphocytes processed before birth?

Answer 28

Liver

Question 29

Where are B-lymphocytes processed throughout life?

Answer 29

Bone marrow

Question 30

Once in the thymus, T-lymphocytes divide rapidly and develop specific reactivity to how many antigens?

Answer 30

One

Question 31

What is the most important thing that happens to T-lymphocytes while in the thymus?

Answer 31

They are checked to ensure that they do not respond to any of the body's own tissues or "self-antigens"

Question 32

If the thymus is responsible for processing T-lymphocytes, can it be removed?

Answer 32

Yes, it processes prior to and right after birth. So you don't have to have it.

Question 33

What happens when a lymphocyte comes in contact with the specific antigen that it has been programmed to respond to?

Answer 33

It causes rapid cell division which produced increased numbers of lymphocytes with identical specificity

Question 34

How is a great diversity of antigens achieved despite being encoded for by only 100-1000 genes?

Answer 34

Shuffling of gene segments during processing

Question 35

How can macrophages, B-cells, and dendritic cells activate lymphocytes?

Answer 35

After engulfing a pathogen, it can present the antigen of the pathogen directly to the correct lymphocyte

Question 36

What do macrophages secrete to promote further reproduction and growth of lymphocyte clones?

Answer 36

Interleukin-1

Question 37

What are the three events required for activation of Helper T-Lymphocytes?

Answer 37

1) Presentation of an antigen bound to MHC II protein on APC or B-cell 2) Binding of matching non-antigenic proteins on Helper and APC or B-cell 3) Secretion, by APC or B-cell, of cytokines including IL-1 and TNF which act on the Helper lymphocyte

Question 38

T-lymphocytes only respond when the antigen is bound to special surface molecules called ________

Answer 38

Major Histocompatibility Complexes (MHCs)

Question 39

What are the three major types of APCs?

Answer 39

Macrophages, B-lymphocytes, and Dendritic cells

Question 40

How many classes of MHC proteins are there?

Answer 40

2

Question 41

MHC1 presents to what lymphocyte?

Answer 41

Cytotoxic T-lymphocytes

Question 42

MHC2s present to what lymphocyte?

Answer 42

Helper T cells

Question 43

Where are T-cells produced?

Answer 43

They are produced in the bone marrow and them processed in the thymus

Question 44

What do Helper T-cells do?

Answer 44

They secrete lymphokines that enhances the activation of processed B-lymphocytes

Question 45

Without the enhancement form Helper T-cells, what would happen to the number of antibodies?

Answer 45

The number of antibodies secreted by B-cells would be insufficient, and the immune response wouldn't be great

Question 46

Can a B-cell act as an APC?

Answer 46

Yes, immunoglobulin receptors can bind with antigens to engulf them and present them on an MHC II protein

Question 47

What are the steps of an activated B-cell becoming a plasma cell?

Answer 47

Activated B-cell --> lymphoblast --> plasmoblast --> plasma cell

Question 48

What is the primary response?

Answer 48

When you are introduced to a pathogen for the first time and your body produces antibodies to mount an immune response

Question 49

What is a secondary response?

Answer 49

This is a greater more rapid response because your body has been introduced to this pathogen before and it is recognized by memory cells. This is why immunizations are important.

Question 50

Do all activated B-cells become plasma cells?

Answer 50

No, some turn into memory cells

Question 51

About how long does it take the body to form an immune response to a new pathogen?

Answer 51

About a week with a low number of antibodies that are produced for a few days to weeks

Question 52

How long does the body take to start a secondary immune response?

Answer 52

A few hours with a high number antibodies that are produced for a few months

Question 53

Most antigens are ______ meaning they have two binding sites.

Answer 53

Bivalent

Question 54

What does the constant portion of the antibody determine?

Answer 54

General properties like opsonization

Question 55

What causes specificity at the binding site of an antigen?

Answer 55

Amino acids

Question 56

What are the five classes of antibodies?

Answer 56

IgG, IgA, IgM, IgE, IgD

Question 57

Which antibody (immunoglobulin) is the most numerous in the body?

Answer 57

IgG making of 75% of all antibodies

Question 58

What is IgG responsible for?

Answer 58

Immune response in the thymus

Question 59

What is IgA responsible for?

Answer 59

Immune function of mucus membranes

Question 60

What is IgM responsible for?

Answer 60

Presented on B-cells/control of B-cells

Question 61

What is IgE responsible for?

Answer 61

Allergy responses

Question 62

What is IgD responsible for?

Answer 62

Co-expressed with IgM on B-cells

Question 63

What are the 4 actions of antibodies?

Answer 63

1) Agglutination 2) Precipitation 3) Neutralization 4) Lysis

Question 64

What is agglutination?

Answer 64

large invaders become bound together by antibodies and form clumps

Question 65

What is Precipitation?

Answer 65

Linked molecules become so large they become insoluble

Question 66

What is Neutralization?

Answer 66

Bind antibodies cover and therefore inactivate toxic sites

Question 67

What is lysis?

Answer 67

Rupture cell membranes (usually requires amplification from the complement pathway)

Question 68

What starts the Classic complement cascade?

Answer 68

A specific antigen/antibody (IgM or IgG) binding where the constant portion of the antibody binds to C1 and activates it

Question 69

What is C3b responsible for?

Answer 69

Opsonization of bacteria

Question 70

What complement factors activate mast cells and basophils?

Answer 70

C3a, C4a, and C5a

Question 71

Which complement factor is responsible for chemotaxis of white blood cells (neutrophils and macrophages)?

Answer 71

C5a

Question 72

What are the 4 types of T cells?

Answer 72

Helper, Cytotoxic, Suppressor, and Natural killer cells

Question 73

What is the most numerous T-lymphocyte?

Answer 73

Helper T-lymphocytes

Question 74

Why are Helper T-cells so important?

Answer 74

They activate both suppressor and cytotoxic T-cells, and stimulate C-cell growth into plasma cells

Question 75

How do cytotoxic T-cells kill pathogens?

Answer 75

They puncture holes in their membrane with perforin proteins, and then they release cytotoxic substances into their targets

Question 76

Where is the MHC I protein found?

Answer 76

On all nucleated cells

Question 77

How are NK cells different than Cytotoxic T-cells?

Answer 77

They are not antigen specific and they do NOT use MHC proteins

Question 78

What are the major cytokines from Helper T-cells that cause NK cells to proliferate and secrete their cell-killing hormones?

Answer 78

IL-2 and interferon-gamma

Question 79

Do NK cells require IL-2 and interferon-gamma to be activated?

Answer 79

No, this is why they are also part of the innate immune response

Question 80

In the general systemic effects of infection, which Interleukins are released?

Answer 80

IL-1, IL-2, IL-6, and TNF

Question 81

What are some general responses from the systemic effects of infection?

Answer 81

1) increased WBC production 2) increased plasma fatty acids 3) increased amino acids 4) increased acute phase proteins 5) increased cortisol

Question 82

What is Rheumatic fever?

Answer 82

When the body becomes sensitized to tissues in joints and heart valves after exposure to specific Streptococcal toxins

Question 83

What is Multiple Sclerosis is probably due to?

Answer 83

A virus with similar antigenic properties to myelin

Question 84

What happens with Poison Ivy toxin?

Answer 84

The initial exposure induces a mild response, but after repeated exposures the response becomes so extreme that healthy tissue is harmed

Question 85

Allergic tendency is inherited and characterized by excessive _____ antibodies in the blood.

Answer 85

IgE

Question 86

Inactive complement proteins are formed in the ________ and travel around in the ________ until activated.

Answer 86

Liver, bloodstream