Antibody Function

Question 1

what is the strength of the interaction between the antibody and antigen referred to as?

Answer 1

affinity

Question 2

does the ability of antibodies to bind using multiple antigen binding sites affect the strength of the interaction?

Answer 2

yes, greatly increased with multiple

Question 3

in the primary response, what immunoglobulin class is mostly present?

Answer 3

IgM

Question 4

what immunoglobulin classes are produced in the secondary or memory response?

Answer 4

IgA, IgE, and IgG

Question 5

what is the change in antibody class produced called?

Answer 5

class switching

Question 6

why are the antibodies of the memory response higher affinity than those of the primary response?

Answer 6

somatic hypermutation

Question 7

how does an antibody neutralize a virus/toxin/bacteria?

Answer 7

binding to it and blocking it (not called neutralization for bacteria)

Question 8

what immunoglobulin classes are most important in neutralization?

Answer 8

IgG and IgA

Question 9

what is opsonization?

Answer 9

coating of particle with antibody to enhance phagocytosis

Question 10

phagocytic cells have _____________ that bind to the _____________ of antibodies

Answer 10

Fc receptors
Fc region

Question 11

what antibody class is most important in opsonization?

Answer 11

IgG

Question 12

what is opsonization typically directed against?

Answer 12

bacteria, but viruses and other particles (extracellular) can be too

Question 13

what cells does antibody-dependent cell-mediated cytotoxicity involve?

Answer 13

natural killer cells
virally infected cells and tumor cells

Question 14

what antibody class is most important in antibody-dependent cell-mediated cytotoxicity?

Answer 14

IgG

Question 15

what is the most important substance that mast cells release (via degranulation)?

Answer 15

histamine

Question 16

what are mast cells important in protecting against?

Answer 16

parasites

Question 17

what antibody class is important in mediating mast cell degranulation?

Answer 17

IgE

Question 18

what is the major mechanism of allergy?

Answer 18

IgE-mediated hypersensitivity

Question 19

what does the complement system do?

Answer 19

mediates host defense against various extracellular pathogens, especially bacteria

Question 20

what do chemoattractants do?

Answer 20

direct migration of phagocytic cells towards the site of complement activation

Question 21

what antibody classes can activate the complement system?

Answer 21

IgG and IgM

Question 22

what is the major immunoglobulin in the blood and tissues, but not mucosal surfaces?

Answer 22

IgG

Question 23

where are IgM pentamers mainly confined to?

Answer 23

bloodstream

Question 24

what are the major immunoglobulins in mucosal secretions?

Answer 24

IgA dimers

Question 25

how does IgA get to the tract lumen?

Answer 25

binds a polymeric Ig receptor on the basolateral face of an epithelial cell, undergoes transcytosis within vesicles in the cell, then released at the apical surface into the tract lumen

Question 26

how is maternal IgG transferred to the fetus in dogs and cats?

Answer 26

some through placenta, mainly through cololstrum

Question 27

what is the predominant antibody in the colostrum of dogs, cats, ruminants, horses, and pigs?

Answer 27

IgG

Question 28

what receptor does the human placenta have that allows IgG to be transported across the placenta?

Answer 28

neonatal Fc receptors

Question 29

what is antibody-dependent cell-mediated cytotoxicity?

Answer 29

natural killer cells stimulating apoptosis in cells coated with IgG (virally infected or tumor cells)

Question 30

what are the specific receptors on mast cells and natural killer cells bind to their immunoglobulins?

Answer 30

IgE binds to Fc-epsilon receptors on mast cells
IgG binds to Fc-gamma receptors on natural killer cells

Question 31

what animals are born with maternal IgG?

Answer 31

humans, rodents, non-human primates

Question 32

what antibody class(es) can cross the placenta?

Answer 32

IgG

Question 33

what is the predominant antibody in the colostrum of dogs, cats, ruminants, horses, and pigs?

Answer 33

IgG