Module 1 Unit 2

Question 1

are related but distinct immunologic properties that sometimes are confused.

Answer 1

Immunogenicity and antigenicity

Question 2

is the ability to induce a detectable immune response.

Answer 2

Immunogenicity

Question 3

The immune response may be [?] which leads to production of antibodies or cellular leading to the activation of T cells, or both.

Answer 3

humoral

Question 4

is the ability to combine specifically with the final products of the above responses (i.e., antibodies and/or cell-surface receptors of activated T cells). Although all molecules that have the property of immunogenicity also have the property of antigenicity, the reverse is not true.

Answer 4

Antigenicity or specific reactivity

Question 5

Low molecular weight substances are [?].

Answer 5

nonimmunogenic

Question 6

Nonimmunogenics are often referred to as partial or incomplete antigens or [?].

Answer 6

haptens

Question 7

commonly contains only a single determinant site which prevents them from forming crosslinks.

Answer 7

Haptens

Question 8

These antigenic molecules may be made immunogenic when it becomes conjugated with larger carrier or indicator molecules like [?]

Answer 8

proteins, cells or latex particles.

Question 9

There are two basic components of the antigen: the [?] and the [?].

Answer 9

epitope and the carrier molecule

Question 10

The [?] is otherwise known as the antigenic determinant, antigenic site, reactive site or haptenic portion.

Answer 10

epitope

Question 11

This is the immunologically active portion of an antigen which can react with antibodies and T cell receptors.

Answer 11

epitope

Question 12

Epitopes can either be [?] and [?] in form.

Answer 12

linear or conformational

Question 13

[?] consist of sequential amino acids on a single polypeptide chain.

Answer 13

Linear epitopes

Question 14

[?] from the folding of a polypeptide chain/s and nonsequential amino acids are brought into close proximity.

Answer 14

Conformation results

Question 15

The linear conformation is commonly associated with [?] while the conformation is commonly associated with [?].

Answer 15

surface antibody recognitioin

T cell recognitioin

Question 16

refers to the structural element of immunogen that interacts with T and B lymphocytes.

Answer 16

Immunogenic determinant

Question 17

The immunogen must possess at least 2 determinants to be able to stimulate antibody formation or 1 determinant to be able to interact and trigger a [?].

Answer 17

T cell response

Question 18

The number of distinct determinants on an antigen molecule usually varies with its

Answer 18

size and chemical complexity.

Question 19

The carrier component of the antigen is also called the [?], It provides bulk or molecular mass to the antigen molecule. It is also important in the regulation of humoral immune response to the antigen. T cells commonly recognize this portion.

Answer 19

Schelepper molecule

Question 20

B cells recognize the [?].

Answer 20

haptenic portion

Question 21

The [?] may have its own set of integral epitopes as presented by antigen presenting cells.

Answer 21

schlepper molecule

Question 22

Examples of carriers are

Answer 22

albumin, globulin or other synthetic polypeptide

Question 23

Antigen molecules may be

a) univalent and unideterminant (?
(b) multivalent and unideterminant (?)
(c) multivalent and multideterminant (?)

Answer 23

• one epitope of one design or shape
• many epitopes but of only one design
• many epitopes of different designs or shape

Question 24

The immune system discriminates between [?], so that only molecules that are foreign to the self are normally immunogenic.

Answer 24

“self” and “nonself”

Question 25

The capacity to recognize nonself is accompanied by [?], a specific unresponsiveness to self-antigens.

Answer 25

tolerance of self

Question 26

Much of the ability to tolerate self-antigens arises during [?], during which immature lymphocytes are exposed to self components.

Answer 26

lymphocyte development

Question 27

Antigens that have not been exposed to immature lymphocytes during this critical period may be later recognized as [?], or foreign, by the immune system.

Answer 27

nonself

Question 28

The greater the [?], the higher the [?] thus the more immunogenic.

Answer 28

phylogenetic distance | structural disparity

Question 29

Some macromolecules (e.g., collagen and cytochrome c) have been highly conserved throughout evolution thus there is little [?] even across diverse species lines.

Answer 29

immunogenicity

Question 30

Some self-components (e.g., corneal tissue and sperm) are effectively sequestered from the immune system, so that if these tissues are injected even into the animal from which they originated, they will function as [?].

Answer 30

immunogens

Question 31

Substances that are altered from what is normal to the host may become [?].

Answer 31

immunogenic (autoantigen)

Question 32

In cases of cancer cells, there is the production of [?]. These are proteins that underwent mutation.

Answer 32

tumor specific antigen

Question 33

This refers to the heterogeneity in the building blocks that make up the antigen.

Answer 33

Chemical Complexity

Question 34

consisting of repeating units of a single amino acids are poor immunogens regardless of size

Answer 34

Homopolymers

Question 35

[?] of two or more amino acids are more immunogenic

Answer 35

copolymers

Question 36

The general rule is immunogenicity increases with

Answer 36

structural complexity

Question 37

are considered the most immunogenic. It is with many antigenic determinants and contain amino acids which are capable of binding and folding thus imparting epitopes of different specificities.

Answer 37

Proteins

Question 38

are generally considered weak and partial immunogens because they do not possess sufficient chemical diversity. They are also rapidly degraded and thus do not come in contact with immune cells long enough to induce reaction.

Answer 38

Polysaccharides

Question 39

found in pneumococcal capsules and lipopolysaccharides such as endotoxins of gram-negative bacteria are two of the immunogenic forms of polysaccharides.

Answer 39

Pure polysaccharides

Question 40

are considered strong immunogens.

Answer 40

Glycoproteins

Question 41

Immune response is directed against its

Answer 41

carbohydrate epitope.

Question 42

ABO blood group antigens are under this category.

Answer 42

Glycoproteins

Question 43

[?] like hormones are usually weak immunogens.

Answer 43

Polypeptides

Question 44

in the form of RNA and DNA are usually not immunogenic however in some autoimmune disorders like SLE (Systemic Lupus Erythematosus) nucleic acids become immunogenic leading to the formation of autoantibodies.

Answer 44

Nucleic acids

Question 45

If amino acids are found frequently in antigenic site than others these are called

Answer 45

“immunodominant”

Question 46

enhance antigenicity.

Answer 46

Basic or acidic amino acids

Question 47

are more “immunogenic” than DNA since they contain unpaired nucleotides that may function as antigenic determinant. The reactive group of DNA is usually hidden.

Answer 47

RNAs

Question 48

such as triglycerides and other fatty substances are nonimmunogenic unless coupled to proteins.

Answer 48

Pure lipids

Question 49

As a general rule, the larger the molecule the [?].

Answer 49

better as an immunogen

Question 50

Molecules less than one kilodalton are considered

Answer 50

non immunogenic

Question 51

Molecules more than one but less than 6 kilodalton are considered [?]. Examples under this include insulin, histones and glucagon.

Answer 51

weakly immunogenic

Question 52

Molecules more than ten kilodalton are considered more immunogenic like [?].

Answer 52

albumin and gamma globulin

Question 53

which is more than 1,000,000dalton is considered an excellent immunogen.

Answer 53

Hemocyanin

Question 54

The significance of size in immunogenicity is that [?] increase proportionately with size.

Answer 54

number of epitopes

Question 55

Large sized molecules become easily phagocytosed and processed by macrophages to become more attractive to

Answer 55

T cells

Question 56

must be exposed and accessible to the receptors of antibodies or T cell receptors (TCR’s) so the antigen can be bound.

Answer 56

Epitopes

Question 57

cannot be reacted upon thus pretreatment of cells may be necessary in order to bring out these epitopes to the surface so that it can be recognized and bound.

Answer 57

Hidden (internally located) determinant groups

Question 58

This is one reason why proteins are more immunogenic than others because of their [?] which allows greater accessibility of their determinant groups.

Answer 58

tertiary conformational structure

Question 59

Refers to the maintenance of the conformational structure of the protein antigen. Loss, alteration or denaturation of such lead to loss of reactivity.

Answer 59

Rigidity

Question 60

Refers to the physical state of the antigen molecule.

Answer 60

Insolubility

Question 61

Antigens must be [?] to be immunogenic.

Answer 61

particulate and insoluble

Question 62

[?], [?]due to heat, [?] to insoluble carrier substance contribute to immunogenicity.

Answer 62

Intermolecular crosslinking aggregation attachment of hapten

Question 63

Antigen is taken up and processed by [?].

Answer 63

macrophages

Question 64

releases hydrolytic products which are the immunogenic units rather than the intact antigen molecule. This complexes with macrophage RNA.

Answer 64

Macrophage processing

Question 65

The [?], when released, stimulate antibody production.

Answer 65

macrophage RNA

Question 66

[?] during processing also reveal hidden antigenic sites.

Answer 66

Partial digestion

Question 67

Immunogenic components are coupled to [?] and antigen is presented at the surface of the macrophage to be recognized by the lymphocytes.

Answer 67

MHC class II molecules

Question 68

Examples of good immunogens used as vaccines are

Answer 68

killed organisms (eg. Typhoid bacilli) attenuated or altered bacteria (eg. Sabin polio virus) detoxified toxins (eg. Diphtheria and tetanus toxoids) artificially assembled microbial components (eg. Hepatitis B virus subunits)

Question 69

are chemicals which when administered with antigen enhances or provokes immunity. They are commonly mixed with antigens especially for manufacture of vaccines.

Answer 69

Adjuvants

Question 70

Mechanism of action of adjuvants include: 1. Increases the [?] of the immunogen 2. Increased [?] and local delayed released of the antigen 3. Delayed [?] of the antigen since the antigen is surrounded by the adjuvant. 4. Prolonged [?] which increases contact of antigen with immunocompetent cells. 5. [?] which leads to the migration of leukocytes; increasing the number of leukocytes and macrophages involved in antigen processing. 6. [?] of lymphocytes are also stimulated.

Answer 70

1. effective size 2. phagocytic uptake 3. destruction and elimination 4. immunogen retention 5. Local granuloma formation 6. Nonspecific proliferation

Question 71

Examples of adjuvants include [?] made up of suspension of aluminum hydroxide mixed with antigen. x

Answer 71

alum precipitate

Question 72

The [?] precipitates the antigen which increases size and slows down release of antigen.

Answer 72

salt

Question 73

Another is [?], a long hydrocarbon molecule present in human sebaceous gland secretions and shark liver oil and a component of [?], an immunologic potent vaccine adjuvant.

Answer 73

squalene | MF-59

Question 74

[?] is another classic example. This could either be the complete form made of water in oil emulsion and killed Mycobacterium tuberculosis (its cell wall contains Muramyl dipeptide which activates macrophages making it more phagocytic) or incomplete form which does not contain the M. tuberculosis component.

Answer 74

Freund’s adjuvant