"Microbiology/Immunology Immune Response" MARY Flashcards Preview

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Flashcards in "Microbiology/Immunology Immune Response" MARY Deck (23)
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1
Q

What is the period of time called between when an antigen is introduced, and when antibody to that antigen can be detected?

A

Lag, inductive or latent phase

2
Q

Which response to antigen is faster in terms of making antibody, primary response or secondary response?

A

Secondary

3
Q

Name the critical differences between primary and secondary responses.

A

The secondary response displays:

  1. shorter lag time
  2. requires less antigen to induce a response
  3. higher rates of antibody synthesis
  4. higher peak of antibody titer possible
  5. predominance of IgG
  6. higher affinity of antibody for antigen
  7. longer persistence of antibody
4
Q

What is an idiotype?

A

A variable region on surface antibody

5
Q

How many idiotypes can one B cell express?

A

One, that is why the full complement of B cells is necessary to respond to different antigens

6
Q

What is the “clonal expansion” of the responsive cells?

A

When a B cell proliferates, for example sometimes B cells can make up to 1000 daughter cells in as little as 10 days

7
Q

As the immune response continues, over time the antibodies being made express a higher affinity for the antigen. Why?

A

Selective expansion of successful clones

8
Q

The total population of B cells make up the ____ of antibody specificities.

A

repertoire

9
Q

What is the surface antigen on T-helper cells?

A

CD4

10
Q

T/F: T-cells recognize a different set of antigens than B-cells.

A

True, not only do they see antigens differently, they recognize different parts of an antigen.

11
Q

Most antigens that T-cells react to are:

A

proteins or peptides

12
Q

T-cells can activate B cells to do what?

A

Differentiate into plasma cells

13
Q

Factors produced by what cells are responsible for the shift from IgM to IgG?

A

T-cells

14
Q

If B-cells do not differentiate into plasma cells, what else can they become?

A

Memory cells

15
Q

How is antigen presented in a way that the T-cell will react to it?

A

The antigen can be on the surface of a presenting cell, or the antigen can be part of a co-stimulatory molecule like MHC.

16
Q

T/F: All immunogens require T-cell help to produce a response.

A

False. There are T-independent antigens, generally polymeric molecules having a large number of repeating units (ie mitogens) than can cause a cross-linking of the antibody on the B-cell. There are others, too, ie toll receptors etc.

17
Q

What is the basic function of antigen presenting cells (APCs)?

A

To initiate the interaction with antigen by endocytosis or phagocytosis.

18
Q

Lymphocytes respond to antigen that is presented with ____ MHC.

A

self

19
Q

What is the most important cell surface antigen?

A

CD28:B7. The T-cell has CD28 which binds to B7 antigen on the APC.
CD40L is also an important co-stimulatory signal on T-helper cells that binds to CD-40L on the B-cell.

20
Q

T/F: The presentation of antigen without co-stimulation between APC and lymphocyte does not induce immunity.

A

True

21
Q

What are the requirements of a “professional” APC?

A
  1. Take up and process antigen
  2. Have MHC-II on its surface
  3. Present the antigen with the MHC-II antigen
  4. Provide a co-stimulatory signal, ie B7.
22
Q

T/F: B-cells are capable of processing antigen, expressing MHC-II antigen and expressing co-stimulation.

A

True

23
Q

Give a few examples of the “best” APCs.

A

Dendritic cells

Langerhans cells

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