ANTIGENS Flashcards

ppt

1
Q

Macromolecules that induce the formation of antibodies or sensitized T cells in an immunocompetent host.

A

Immunogens

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2
Q

Substances that react with antibodies or sensitized T cells but may not evoke an immune response initially.

A

Antigens

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3
Q

are small molecules that are antigenic but not
immunogenic by themselves.

A

Haptens

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4
Q

Low molecular weight particles that can bind to an antibody but must be attached to a macromolecule as a carrier to stimulate a specific immune response

A

Haptens

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5
Q

T/F: Haptens are small molecules that are antigenic and
immunogenic by themselves.

A

False

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6
Q

also known as determinant sites

are molecular shapes or configurations on antigens that are recognized by B cells or T cells.

they dictate the specificity of the immune response.

A

EPITOPE

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7
Q

These epitopes consist of a continuous sequence of amino
acids on a single polypeptide chain.

A

LINEAR EPITOPE

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8
Q

They result from the three-dimensional folding of a
polypeptide chain, bringing amino acids from different parts of the linear sequence into close proximity.

A

CONFORMATIONAL EPITOPE

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9
Q

three determinants of epitope

A

▪ Unideterminant, univalent
▪ Unideterminant, multivalent
▪ Multideterminant, multivalent

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10
Q

FACTORS CONTRIBUTING TO IMMUNOGENICITY

A

Factors related to the antigens
Factors related to the host
Factors related to the exposure

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11
Q

The immune system has evolved to differentiate between self and non-self.

A

FOREIGNESS

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12
Q

“self” antigens; originate from the host’s own body

A

Autologous

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13
Q

derived from a genetically identical individual, such as an
identical twin

A

Syngeneic/Isogenic

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14
Q

from a genetically different member of the same species

A

Allogenic/Homologous

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15
Q

from a different species, such as animal tissues or organs

A

Xenogenic/Heterologous

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16
Q

A phenomenon where an antibody generated against
one antigen can also bind to a similar, but distinct, antigen

A

Cross-reactivity

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17
Q

This processing often involves the breakdown or degradation of the immunogen into smaller fragments that can be displayed on MHC molecules for recognition by T cells.

A

DEGRADABILITY

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18
Q

Generally, larger molecules are more immunogenic.

A

MOLECULAR WEIGHT (MW)

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19
Q

mw that is recognizable by the immune system

A

10,000 daltons

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20
Q

mw that is most potent immunogens

A

> 100,000 daltons

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21
Q

Stability allows the immunogen to persist within the host’s body for a sufficient duration, giving the immune system adequate time to mount an effective response.

A

STRUCTURAL STABILITY

22
Q

substances that, when administered alongside an
immunogen, enhance the immune response to that
immunogen.

A

Adjuvants

23
Q

Complex molecules, with a higher diversity of antigenic determinants or epitopes, are more likely to be recognized by the immune system and elicit a response.

A

CHEMICAL COMPOSITION AND MOLECULAR COMPLEXITY

24
Q

are highly antigenic because of their large size and complex structures

A

Proteins

25
Q

Simple molecules though capable of acting as antigens, are generally less immunogenic.

A

lipids
carbohydrates
nucleic acids

26
Q

are less antigenic but can elicit immune responses when bound to proteins or lipids

A

Carbohydrates

27
Q

are weakly antigenic on their own but can become more antigenic when conjugated to larger molecules.

A

Nucleic acids and lipids

28
Q

age that tend to have a diminished response to antigenic
stimulation

A

Older individuals

29
Q

age that immune systems are not fully developed, leading to a weaker response to immunogens.

A

Neonates’

30
Q

are responsible for presenting
antigens to T cells, a critical step in initiating both humoral and cellular immunity.

A

MHC molecules (major histocompatibility complex)

31
Q

Individuals facing malnutrition, fatigue, or stress are less likely to mount a successful immune response.

A

OVERALL HEALTH

32
Q

The dose required to generate a response varies depending on the immunogen and the individual.

A

DOSE OF IMMUNOGEN

33
Q

FACTORS RELATED TO THE ANTIGENS

A
  • FOREIGNESS
  • DEGRADABILITY
  • MOLECULAR WEIGHT (MW)
  • STRUCTURAL STABILITY
  • CHEMICAL COMPOSITION AND MOLECULAR COMPLEXITY
34
Q

FACTORS RELATED TO THE HOST

A

AGE
GENETIC PREDISPOSITION
OVERALL HEALTH

35
Q

FACTORS RELATED TO EXPOSURE

A

DOSE OF IMMUNOGEN
ROUTE OF INOCULATION

36
Q

This highlights the importance of administering vaccines and medications through the appropriate route for optimal effectiveness.

A

ROUTE OF INOCULATION

37
Q

TYPES OF ANTIGENS

A

AUTOANTIGEN
ALLOANTIGEN
HETEROANTIGEN
MITOGENS
SUPERANTIGENS
ENDOGENOUS ANTIGENS
EXOGENOUS ANTIGENS
T-CELL DEPENDENT ANTIGENS
SEQUESTERED ANTIGENS

38
Q

▪ Antigens that belong to the host.
▪ They are not capable of eliciting an immune response under normal circumstances.

A

AUTOANTIGEN

39
Q

Come from other members of the host’s species.

A

ALLOANTIGEN

40
Q

Come from a different species than the host.

A

HETEROANTIGEN

41
Q

a type of heteroantigen that exist in unrelated plants or animals.

A

Heterophile antigens

42
Q

A mitogen is a substance that stimulates mitosis (cell division) in all T cells or all B cells, regardless of antigen specificity.

A

MITOGENS

43
Q

Microbial proteins that can act as potent T- cell mitogens.

A

SUPERANTIGENS

44
Q

Massive T-cell activation leads to a surge in cytokine release, resulting in a systemic inflammatory response known as

A

toxic shock syndrome

45
Q

▪ Generated within a cell
▪ Typically derived from viruses or intracellular bacteria that are actively replicating within the host cell.

A

ENDOGENOUS ANTIGENS

46
Q

▪ originate from outside the cell.
▪ are taken up by specialized antigen- presenting cells (APCs), such as macrophages, dendritic cells, and B cells, through phagocytosis or endocytosis.

A

EXOGENOUS ANTIGENS

47
Q

Require T-cell help for B cells to mount an effective antibody response.

A

T-CELL DEPENDENT ANTIGENS

48
Q

These antigens typically possess
repetitive structures

A

T-CELL DEPENDENT ANTIGENS

49
Q

activated by binding to immunoglobulin receptors and other receptors, such as Toll-like receptors

A

type 1 T-CELL INDEPENDENT ANTIGENS

50
Q

primarily activated by dendritic cells and macrophages.

A

type 2 T-CELL INDEPENDENT ANTIGENS

51
Q

▪ A.k.a. cryptic antigens

▪ Self-antigens hidden from the immune system during its development.

▪ This concealment prevents the immune system from learning to tolerate these antigens, potentially leading to autoimmune reactions if they are later exposed.

A