The Immune Resonse

Question 1

What are the phases of antibody production?

Answer 1

1- Lag phase
2-Logarithmic/ exponential rate
3- Steady state
4- Decay/ decline phase
5- Extended period of time when a small amount of antibody can be detected

Question 2

What is the lag phase?

Answer 2

The amount of time before antibody can be detected. Typically 4-7 days for a primary response.

Question 3

What Ig is most prevalent during a primary response?

Answer 3

IgM

Question 4

When is IgG detectable after exposure?

Answer 4

About 2 weeks after the immune response

Question 5

Compare a secondary immune response to a primary immune response?

Answer 5

Secondary is stronger, faster.

Shorter lag time and higher rates of antibody synthesis, reaching a higher peak of antibody titre.

Requires less antigen to stimulate.

Ig is typically of higher affinity.

Question 6

Does Ig stay around longer in a primary response or a secondary response?

Answer 6

A secondary response

Question 7

What type of Ig doe memory B cells make?

Answer 7

IgG

Question 8

What is an idiotype?

Answer 8

A single variable region expressed on a B cell

Question 9

What occurs when a B cell finds its matching antigen?

Answer 9

Antigen is presented with T cell help

Clone starts expanding

Daughter cells are produced

Question 10

What is clonal expansion?

Answer 10

1 B cell can make up to 1000 daughter cells in 10 days. It is an increase in number of B cells that are specific to the antigen

Question 11

As the immune response, what happens to the affinity of antibodies? Why?

Answer 11

The “affinity” of the antibodies increase because of selective expansion of the B cells that have the highest affinity to the antigen

Question 12

What antibodies are still made when the antigen concentration drops?

Answer 12

The highest affinity antibodies

Question 13

What are the surface antigens of Helper T cells?

Answer 13

CD3 and CD4

Question 14

What is a Hapten-Carrier?

Answer 14

Small molecule attached to a large carrier protein that can illicit an immune response

Question 15

What is the difference between how T cells and B cells see antigen?

Answer 15

T cels antigens are small sequences of peptide. B cells see conformations

Question 16

What is needed to activate Helper T cells?

Answer 16

Antigen and MHC, co stimulatory molecules

Question 17

How do activated Helper T cells activate B cells?

Answer 17

T cells proliferate and then produce factors that activate B cells

Question 18

How do APCs get antigens?

Answer 18

Endocytosis/ phagocytosis

Question 19

What enhances activity of APCs?

Answer 19

1- Interaction with compliment
2- Pre-existing antibody
3- specific receptors that recognize pathogens

Question 20

What happens to an antigen when it is taken up by an APC?

Answer 20

The antigen is digested and a highly immunogenic form of the antigen is created

Question 21

How are antigen’s presented?

Answer 21

MHC I (CD8+) and MHC II (CD4+)

Question 22

Who provides the co-stimulatory signals for T lymphocytes?

Answer 22

APCs

Question 23

What are the 4 requirements of Professional APCs?

Answer 23

1- Take up and process antigen
2- Have MHC class II antigen on its surface
3- Present antigen with MHC class II antigen
4- Provide co-stimulatory signal B7

Question 24

What is the receptor for B7 on T lymphocytes?

Answer 24

CD28

Question 25

What are two examples of APCs?

Answer 25

Dendritic Cells and langerhans cells