Specific Acquired Immunity

Question 1

Antigen

Answer 1

Substance/ foreign particle that stimulates your immune system to produce antibodies against it
Ex: bacteria, virus, toxin, parasite, chems, pollen, proteins, peptides, lipids, polysaccharides

Question 2

Immunogen

Answer 2

Induces a specific immune response

Question 3

Epitope/ antigenic determinant

Answer 3

Part of an antigen that’s recognized by an antibody

Question 4

Tolerogen

Answer 4

Antigen that induces immunologic tolerance

Question 5

Allergen

Answer 5

Antigen that induces anaphylaxis (hypersensitivity reaction from mast-cell granulation)
Ex: flower, medicine, hair, dust, etc.

Question 6

Tumor antigens

Answer 6

Presented by an MHC 1 molecule on the surface of tumor cells
Specific ones only in tumors

Question 7

Autoantigens

Answer 7

Protein/ complex of proteins recognized by the immune system of patients suffering from a specific autoimmune disease

Question 8

Immunogenicity

Answer 8

Ability of a molecule/ microbe or cell to be recognized by hosts immune cells and elicit an immune response

Question 9

Antigenicity

Answer 9

The ability of a molecule to bind and react with the products of an immune response

Question 10

T/F: Not all antigens are immunogens while all immunogens are antigens

Answer 10

TRUE

Question 11

What is the basis for antigen (Ag) classification?

Answer 11

Complete/ incomplete antigen
Source/ origin of Ag
According to whether need the help of T cells when B cells produce Ab
Based on chemical nature

Question 12

Complete antigens

Answer 12

Proteins in nature, large in molecular size and capable of stimulating an immune response by themselves

Question 13

Hapten

Answer 13

Incomplete antigen
Reacts with specific antibody, made immunogenic by conjugation to a suitable carrier
Ex: penicillin

Question 14

Exogenous Ag (source/ origin)

Answer 14

Entered the body from the outside
Ex: exhalation, injection or ingestion
By endocytosis or phagocytosis, taken into APCs and processed into fragments

Question 15

Endogenous Ag (source/ origin)

Answer 15

Generated in cell from cell metabolism or because of viral/ intracellular bacterial infection

Question 16

Protein Ags (chemical nature)

Answer 16

Immunogens
Pure, glycoproteins or lipoproteins

Question 17

Polysaccharide Ag (chemical nature)

Answer 17

Immunogens
Pure polysaccharides or liposaccharides

Question 18

Nucelic acid antigens (chemical nature)

Answer 18

Poorly immunogenic
Become immunogenic when single stranded or when complexed with proteins

Question 19

Lipid Ag (chemical nature)

Answer 19

Non-immunogenic (haptens)
Stimulate T cell and produce a cell-mediated response

Question 20

T-dependent antigens

Answer 20

Don’t directly stimulate the production of the antibody without the help fo T cells ‘
Ex: proteins

Question 21

T-independent Ag

Answer 21

Directly stimulate B cells to produce antibody without help of T cell
Production of IgM
Ab and no secondary response

Question 22

Superantigens (SAgs)

Answer 22

Result in excessive activation of the immune system
Causes non-specific activation of T cells resulting in polyclonal T cell activation and massive cytokine release

Question 23

How are SAgs produced?

Answer 23

By some pathogenic viruses and bacteria most likely as a defense mechanism against the immune system

Question 24

Conventional antigen (Normal antigrn)

Answer 24

Stimulate the production of monoclonal/ oliclonal T cell response

Question 25

Foreigness

Answer 25

Self and non self, only foreign molecules are immunogenic (bovine serum albumin)

Question 26

Molecular size

Answer 26

Molecular mass less that 5,000 to 10,000 Da are poor immunogens (insulin)

Question 27

Chemical Composition

Answer 27

More complex the substance is chemically the more immunogenic it will be

Question 28

Physical form

Answer 28

Antigens are more immunogenic than soluble ones and denatured more immunogenic that the native form

Question 29

How does age influence immunogenicity?

Answer 29

Diminished in very young and very old

Question 30

Route of AG

Answer 30

SubQ or IM route is better than IV or intragastric routes Can also alter the nature of response

Question 31

What are the 2 branches of adaptive immunity?

Answer 31

Humoral and cell-mediated

Question 32

Humoral immunity

Answer 32

Production of antibody molecules in response to an antigen Mediated by B cells

Question 33

Cell-mediated immunity

Answer 33

Production of cytotoxic T cells, activated macrophages, activated NK cells and cytokines in response to an Ag