Antibodies II

Question 1

Response to an antigen that immune system has never encountered before

Answer 1

Primary Response

Question 2

Response to an antigen previously encountered

Answer 2

Secondary Response

Question 3

A primary response is dominated by

-affinity for antibody is low

Answer 3

IgM

Question 4

A secondary response is dominated by

-affinity for antibody is high

Answer 4

IgG

Question 5

Larger and longer than primary responses

Answer 5

Secodary response

Question 6

Allows serological diagnosis of a recent infection

Answer 6

Presence of IgM

Question 7

If the immune response is dominated by IgM, exposure must have been

Answer 7

Recent

Question 8

A newborn, because of transplacental transfer of IgG, has antibody to all pathogens previously encountered by its

Answer 8

Mother

Question 9

Not transported across the placenta

Answer 9

IgM

Question 10

Neonatal pathogen-specific IgM must have been made in response to exposure in utero and is indicative of

Answer 10

Infection

Question 11

Class switching is produced by splicing of

Answer 11

Constant-region DNA

Question 12

The first antibody made in an immune response is always

Answer 12

IgM

Question 13

In a ‘class switch’ VDJ segments which encode the VH domain are retained, but the DNA that encodes IgM constant regions is

Answer 13

Deleted

Question 14

The VDJ exon then becomes associated with DNA that encodes an

Answer 14

IgG constant region

Question 15

Combining site specificity thus stays the same, but the

Answer 15

Isotype changes

Question 16

The signals in DNA, and the mechanism of splicing, are different from those that assemble

Answer 16

VDJ regions

Question 17

The new isotype is determined by the size of the DNA segment

Answer 17

Deleted

Question 18

Heavy-chain constant-region genes are adjacent to one another, downstream from the

Answer 18

VDJ exon

Question 19

The VDJ segments can become associated with any downstream

-Dependent on the amount of DNA deleted

Answer 19

Constant-region segment

Question 20

Class switching is

-because once DNA is deleted it can not be regained

Answer 20

Irreversible

Question 21

Thus a cell which has switched from production of IgM to production of IgG2 cannot go on to switch to production of IgA1, because the DNA of the IgA1 constant region

Answer 21

Gone

Question 22

Class switching is regulated by

Answer 22

Cytokines

Question 23

Switching occurs at ‘S regions’ in DNA. These regions must be transcribed to participate in

Answer 23

Switching

Question 24

Particular cytokines activate transcription of particular S regions, and this in part determines the mixture of isotypes created during an

Answer 24

Immune response

Question 25

A monoclonal population may represent a

Answer 25

Malignant or pre-malignant state

Question 26

A polyclonal popultion may represent an

Answer 26

Inflammatory process