Antigens and Antibodies

Question 1

Immunogen

Answer 1

An antigen that evokes a specific immune response

Question 2

Alloantigens

Answer 2

Tissue specific antigen, present in one individual of a species but not in others

Question 3

Conformational determinant

Answer 3

Determinant lost by denaturation

Question 4

Linear determinant

Answer 4

Ig may only bind to denatured protein, unless the linear determinant is accessible

Question 5

Neoantigenic determinant

Answer 5

Determinant created by proteolysis

Question 6

T-dependent antigens are typically

Answer 6

Proteins, recognized as linear determinants

Question 7

T-independent antigens are typically

Answer 7

Non protein Ags, such as polysaccharides and lipids. Usually have multiple identical epitopes that can cross link several BCRs

Question 8

y/d T cells

Answer 8

Exist in epithelial/mucosal compartments
Recognition of lipid Ags, DAMPs
Not MHC/HLA restricted

Question 9

Immunodominant epitopes

Answer 9

Immune responses against only very few peptides that can be presented to T cells

Question 10

Hapten

Answer 10

Small molecule which cannot elicit immune response alone, cannot bind MHC/HLA
They do induce a response when coupled with carrier protein

Question 11

Circulating Abs are

Answer 11

Soluble glycoproteins that recognize and bind Ags

Question 12

Digestion of Ab with papain gives you

Answer 12

Separation of the two Ag binding regions and the Fc region

Question 13

Digestion of Ab with pepsin gives you

Answer 13

F(ab)2- retains single bivalent Ag binding capability

Question 14

Hypervariable region

Answer 14

Intimately involved in Ag binding by creating and interaction site that is complementary in shape, charge and hydrophobicity to the epitope it binds

Question 15

IgM

Answer 15

5-10% total serum Abs
First Ab produced in primary response to antigen
Produced by neonates
Pentamer
J-piece-secretory component, bind secretory cells

Question 16

IgG

Answer 16

Most abundant-80% of total serum Abs
Heavily involved in classical pathway
Can cross the placenta

Question 17

IgA

Answer 17

10-15% total serum Ab
Predominant class in external secretions
Polymeric

Question 18

IgE

Answer 18

Low concentration-0.5% total serum Ab
Binds basophils and tissue mast cells with FceRI
Protection against helminths

Question 19

IgD

Answer 19

Membrane bound IgD is Ag specific receptor on B cells, along with IgM- both have same Ag specificity
Less than 1% of total serum Ab

Question 20

Bonds b/w Ag/Ab

Answer 20

Non covalent interactions- 
Hydrogen bonds
Electrostatic
Van der waals
Hydrophobic forces

Question 21

Avidity

Answer 21

Avidity of an Ab for its Ag is dependent on the affinities of the individual Ag combining sites