L6_ The Immune Response

Question 1

What are the four stages of a primary immune response?

Answer 1

Lag, exponential, steady state, decay

Question 2

How long is the lag phase in a primary immune response?

Answer 2

about a week, maximum antibody after about 2 weeks

Question 3

Describe the levels of IgG and IgM in the primary and secondary responses

Answer 3

In primary response it is mainly IgM, in secondary there is roughly the same IgM and huge IgG response.

Question 4

Name some of the ways in which the secondary response differs form the primary response.

Answer 4

1 shorter lag time
2 higher rates of synthesis
3 higher peak titer
4 longer persistence of antibody
5 predominance of IgG
6 Higher Affinity Antibody
7 Requires less antigen

Question 5

As the immune response continues, what happens to the affinity of the antibodies being produced? What is this phenomenon referred to as?

Answer 5

They increase because as less and less antigen is being produced, only the higher affinity antibodies will be able to effectively bind the antigen and be cloned. Clonal Selection Theory

Question 6

What are the main APC in the secondary response?

Answer 6

Memory B-Cells

Question 7

Name two of the main antigen presenting cells (not B-Cells)

Answer 7

Dendritic Cells and Langerhans cells

Question 8

What two signals do T-Cells need for an antigen specific response?

Answer 8

Antigen presenting MHC and B7 (co-stimulator)

Question 9

Describe the typical structure or properties of T-independent antigens.

Answer 9

generally polymeric molecules having a large number of repeating subunits that can perhaps cause a cross linking of the immunoglobulin on the B-Cell. Other T-independent antigents are polyclonal activators of B-cells that provide mitogenic signals to the B-cell that would normally have been provided by a T-Cell (These signals are usually recognized by Toll receptors)

Question 10

What is the co-stimulatory molecule that APCs present to T-Cells

Answer 10

B7

Question 11

Name the 4 requirements of a professional APC

Answer 11

1 must take up and process antigen
2 must have MHC class II on its surface
3 must present the MHC II with antigen
4 must provide co-stimulatory molecule

Question 12

What do adjuvants help to do?

Answer 12

Help induce greater phagocytosis of antigen.