Lecture 4 - Overview of the Immune System

Question 1

Which type of immunity is the first line of defense and fast but nonspecific?

Answer 1

Innate

Question 2

Which type of immunity is slower to develop, usually taking 5-6+ days?

Answer 2

Adaptive

Question 3

Which type of immunity uses a limited number of receptors to detect pathogens that are encoded in the germline?

Answer 3

Innate

Question 4

Which type of immunity uses randomly generated antigen receptors that are highly specific to individual molecules?

Answer 4

Adaptive

Question 5

Which type of immunity induces local inflammation?

Answer 5

Innate

Question 6

Which type of immunity is responsible for specific immune responses, clears infections, and results in memory?

Answer 6

Adaptive

Question 7

The whole immune response can be split up into 8 general phases. Listed below are these 8 phases. What order do they occur in?

1. Activation of antigen-specific B-cells.
2. Elimination of pathogen by effector cells and antibody.
3. Emigration of effector lymphocytes from peripheral lymphoid organs.
4. Inflammation, complement activation, phagocytosis, and destruction of pathogen.
5. Maintenance of memory B-cells and T-cells and high serum or mucosal antibody levels. Protection against reinfection.
6. Formation of effector and memory T-cells.
7. Interaction between antigen-presenting dendritic cells and antigen-specific T-cells: recognition of antigen, adhesion, co-stimulation, T-cell profileration, and differentiation.
8. Interaction of T-cells with B-cells, formation of germinal centers. Formation of effector B-cells (plasma cells) and memory B-cells. Production of antibody.

Answer 7

4, 7, 1, 6, 8, 3, 2, and 5

Question 8

What do pattern recognitino receptors (PRRs) recognize?

Answer 8

PRRs recognize broad categories of molecules that are commonly found in pathogens (pathogen associated molecular patterns, PAMPs).

Question 9

What do dendritic cells use to recognize pathogens?

Answer 9

PRRs

Question 10

How do sensor cells induce an inflammatory response?

Answer 10

Sensor cells induce an inflammatory response by producing mediators such as chemokines and cytokines.

Question 11

Redness, heat, swelling, and pain are all hallmarks of what?

Answer 11

Inflammation

Question 12

Where do immature dendritic cells reside? Where do they migrate to?

Answer 12

Immature dendritic cells reside in peripheral tissues. They migrate (via lymphatic vessels) to regional lymph nodes.

Question 13

What do mature dendritic cells activate? Where do they do this?

Answer 13

Mature dendritic cells activate naive T-cells inlymphoid organs such as lymph nodes.

Question 14

Through which 3 signal steps do antigen presenting cells (APCs) activate T-cells?

Answer 14

Activation, Survival, Differentiation

Question 15

Which molecule presents antigen to T-cells?

Answer 15

Antigen is presented using a major hisocompatibility complex (MHC), which interacts with TCR.

Question 16

True or False?:

The epitope of an antigen is always easily accessible.

Answer 16

False

The epitope of an antigen can be a piece of peptide buried within a protein.

Question 17

What is the secreted form of the BCR also called?

Answer 17

Antibody or Immunoglobulin

Question 18

Where do antibodies circulate?

Answer 18

Antibodies circulate in the serum (fluid component of blood).

Question 19

True or False?:

B-cells and T-cells arise and mature in the bone marrow.

Answer 19

False.

B-cells arise and mature in the bone marrow. T-cells arise from bone marrow progenitors but are generated and mature in the thymus.

Question 20

How do BCRs and TCRs differ in the forms they exist in?

Answer 20

BCRs can be membrane-bound or secreted as antibodies while TCR only exists membrane-bound.

Question 21

How do BCRs and TCRs differ in their ability to see antigen?

Answer 21

BCR can see Ag in its natural form while TCR can only see small pieces of the Ag bound to molecules of the MHC on the surface of APCs.

Question 22

True or False?:

Individual B- and T-cells each have an individual specificty for a single antigen. Each lymphocytes expresses many identical copies of one receptor with specificity for one antigen.

Answer 22

True

Question 23

How are potentially self-reactive immature lymphocytes removed?

Answer 23

Lymphocytes are removed by clonal deletion if they react to self antigen?

Question 24

What happens when a naive B- or T-cell interacts with it specific antigen?

Answer 24

When a naive B- or T-cell interacts with its specific antigen, it is selected and becomes activated. Activation results in proliferation, producing a large number of clones. Each clone is reactive against the antigen that initially stimulated the original lymphocyte.

Question 25

What gives rise to effector cells?

Answer 25

Effector cells are formed from T- and B-cells that have been activated in lymphoid organs.

Question 26

What is the difference between humoral immunity and cell-mediated immunity?

Answer 26

Humoral immunity combats pathogens via antibodies. Cell-mediated immunity involves primarily T lymphocytes.

Question 27

True or False?:

Cell-mediated immunity is mediated by B-cells.

Answer 27

False

Cell-mediated immunity is mediated by T-cells.

Question 28

True or False?:

Humoral immunity is mediated by antibodies produced by B-cells.

Answer 28

True

Question 29

True or False?:

Helping to activate B-cells, helping to activate macrophages, and directly killing infected cells are all activites of T-cells in which type of immunity?

Answer 29

Cell-Mediated Immunity

Question 30

How does humoral immunity contribute to adaptive immunity?

Answer 30

Humoral immunity contributes to adaptive immunity by producing specific antibodies.