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Flashcards in Module 1 Unit 2 Deck (74)
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1
Q

are related but distinct immunologic properties that sometimes are confused.

A

Immunogenicity and antigenicity

2
Q

is the ability to induce a detectable immune response.

A

Immunogenicity

3
Q

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

A

humoral

4
Q

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.

A

Antigenicity or specific reactivity

5
Q

Low molecular weight substances are [?].

A

nonimmunogenic

6
Q

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

A

haptens

7
Q

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

A

Haptens

8
Q

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

A

proteins, cells or latex particles.

9
Q

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

A

epitope and the carrier molecule

10
Q

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

A

epitope

11
Q

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

A

epitope

12
Q

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

A

linear or conformational

13
Q

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

A

Linear epitopes

14
Q

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

A

Conformation results

15
Q

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

A

surface antibody recognitioin

T cell recognitioin

16
Q

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

A

Immunogenic determinant

17
Q

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 [?].

A

T cell response

18
Q

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

A

size and chemical complexity.

19
Q

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.

A

Schelepper molecule

20
Q

B cells recognize the [?].

A

haptenic portion

21
Q

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

A

schlepper molecule

22
Q

Examples of carriers are

A

albumin, globulin or other synthetic polypeptide

23
Q

Antigen molecules may be

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

A
  • one epitope of one design or shape
  • many epitopes but of only one design
  • many epitopes of different designs or shape
24
Q

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

A

“self” and “nonself”

25
Q

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

A

tolerance of self

26
Q

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

A

lymphocyte development

27
Q

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

A

nonself

28
Q

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

A

phylogenetic distance

structural disparity

29
Q

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

A

immunogenicity

30
Q

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 [?].

A

immunogens

31
Q

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

A

immunogenic (autoantigen)

32
Q

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

A

tumor specific antigen

33
Q

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

A

Chemical Complexity

34
Q

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

A

Homopolymers

35
Q

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

A

copolymers

36
Q

The general rule is immunogenicity increases with

A

structural complexity

37
Q

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.

A

Proteins

38
Q

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.

A

Polysaccharides

39
Q

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

A

Pure polysaccharides

40
Q

are considered strong immunogens.

A

Glycoproteins

41
Q

Immune response is directed against its

A

carbohydrate epitope.

42
Q

ABO blood group antigens are under this category.

A

Glycoproteins

43
Q

[?] like hormones are usually weak immunogens.

A

Polypeptides

44
Q

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.

A

Nucleic acids

45
Q

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

A

“immunodominant”

46
Q

enhance antigenicity.

A

Basic or acidic amino acids

47
Q

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

A

RNAs

48
Q

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

A

Pure lipids

49
Q

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

A

better as an immunogen

50
Q

Molecules less than one kilodalton are considered

A

non immunogenic

51
Q

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

A

weakly immunogenic

52
Q

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

A

albumin and gamma globulin

53
Q

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

A

Hemocyanin

54
Q

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

A

number of epitopes

55
Q

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

A

T cells

56
Q

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

A

Epitopes

57
Q

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.

A

Hidden (internally located) determinant groups

58
Q

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

A

tertiary conformational structure

59
Q

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

A

Rigidity

60
Q

Refers to the physical state of the antigen molecule.

A

Insolubility

61
Q

Antigens must be [?] to be immunogenic.

A

particulate and insoluble

62
Q

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

A

Intermolecular crosslinking
aggregation
attachment of hapten

63
Q

Antigen is taken up and processed by [?].

A

macrophages

64
Q

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

A

Macrophage processing

65
Q

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

A

macrophage RNA

66
Q

[?] during processing also reveal hidden antigenic sites.

A

Partial digestion

67
Q

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

A

MHC class II molecules

68
Q

Examples of good immunogens used as vaccines are

A

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)

69
Q

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

A

Adjuvants

70
Q

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.

A
  1. effective size
  2. phagocytic uptake
  3. destruction and elimination
  4. immunogen retention
  5. Local granuloma formation
  6. Nonspecific proliferation
71
Q

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

A

alum precipitate

72
Q

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

A

salt

73
Q

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.

A

squalene

MF-59

74
Q

[?] 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.

A

Freund’s adjuvant