ANTIGENS

Question 1

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

Answer 1

Immunogens

Question 2

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

Answer 2

Antigens

Question 3

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

Answer 3

Haptens

Question 4

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

Answer 4

Haptens

Question 5

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

Answer 5

False

Question 6

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.

Answer 6

EPITOPE

Question 7

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

Answer 7

LINEAR EPITOPE

Question 8

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

Answer 8

CONFORMATIONAL EPITOPE

Question 9

three determinants of epitope

Answer 9

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

Question 10

FACTORS CONTRIBUTING TO IMMUNOGENICITY

Answer 10

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

Question 11

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

Answer 11

FOREIGNESS

Question 12

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

Answer 12

Autologous

Question 13

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

Answer 13

Syngeneic/Isogenic

Question 14

from a genetically different member of the same species

Answer 14

Allogenic/Homologous

Question 15

from a different species, such as animal tissues or organs

Answer 15

Xenogenic/Heterologous

Question 16

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

Answer 16

Cross-reactivity

Question 17

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.

Answer 17

DEGRADABILITY

Question 18

Generally, larger molecules are more immunogenic.

Answer 18

MOLECULAR WEIGHT (MW)

Question 19

mw that is recognizable by the immune system

Answer 19

10,000 daltons

Question 20

mw that is most potent immunogens

Answer 20

> 100,000 daltons

Question 21

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.

Answer 21

STRUCTURAL STABILITY

Question 22

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

Answer 22

Adjuvants

Question 23

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.

Answer 23

CHEMICAL COMPOSITION AND MOLECULAR COMPLEXITY

Question 24

are highly antigenic because of their large size and complex structures

Answer 24

Proteins

Question 25

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

Answer 25

lipids carbohydrates nucleic acids

Question 26

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

Answer 26

Carbohydrates

Question 27

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

Answer 27

Nucleic acids and lipids

Question 28

age that tend to have a diminished response to antigenic stimulation

Answer 28

Older individuals

Question 29

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

Answer 29

Neonates'

Question 30

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

Answer 30

MHC molecules (major histocompatibility complex)

Question 31

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

Answer 31

OVERALL HEALTH

Question 32

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

Answer 32

DOSE OF IMMUNOGEN

Question 33

FACTORS RELATED TO THE ANTIGENS

Answer 33

- FOREIGNESS - DEGRADABILITY - MOLECULAR WEIGHT (MW) - STRUCTURAL STABILITY - CHEMICAL COMPOSITION AND MOLECULAR COMPLEXITY

Question 34

FACTORS RELATED TO THE HOST

Answer 34

AGE GENETIC PREDISPOSITION OVERALL HEALTH

Question 35

FACTORS RELATED TO EXPOSURE

Answer 35

DOSE OF IMMUNOGEN ROUTE OF INOCULATION

Question 36

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

Answer 36

ROUTE OF INOCULATION

Question 37

TYPES OF ANTIGENS

Answer 37

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

Question 38

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

Answer 38

AUTOANTIGEN

Question 39

Come from other members of the host’s species.

Answer 39

ALLOANTIGEN

Question 40

Come from a different species than the host.

Answer 40

HETEROANTIGEN

Question 41

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

Answer 41

Heterophile antigens

Question 42

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

Answer 42

MITOGENS

Question 43

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

Answer 43

SUPERANTIGENS

Question 44

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

Answer 44

toxic shock syndrome

Question 45

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

Answer 45

ENDOGENOUS ANTIGENS

Question 46

▪ 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.

Answer 46

EXOGENOUS ANTIGENS

Question 47

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

Answer 47

T-CELL DEPENDENT ANTIGENS

Question 48

These antigens typically possess repetitive structures

Answer 48

T-CELL DEPENDENT ANTIGENS

Question 49

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

Answer 49

type 1 T-CELL INDEPENDENT ANTIGENS

Question 50

primarily activated by dendritic cells and macrophages.

Answer 50

type 2 T-CELL INDEPENDENT ANTIGENS

Question 51

▪ 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.