Angela's Immunotherapy

Question 1

What cells are inherent to innate immunity?

Answer 1

NK cells, Macrophages and dendritic cells

Question 2

What is the role of NK cells?

Answer 2

Lymphocytes that recognize and destroy stressed tissues (e.g., by viruses or cancer)

Question 3

What is the role of Macrophages?

Answer 3

Production of soluble cytokines and chemokines that support growth and survival of inflammatory cells

Question 4

Which immune cell secretes IL-1?

Answer 4

Macrophages; IL-1 is pro-inflammatory

Question 5

What Macrophage activities promotes tumor growth?

Answer 5

Macrophages secrete pro angiogenesis molecules (VEGF and basic FGF) and can secrete immunosuppressant cytokines/molecules (prostaglandins E2 and arginase I, and TGF-B)

Question 6

What is the role of Dendritic cells?

Answer 6

Professional antigen presenting cells, link between Adaptive and Innate immunity.

Question 7

What are the two major cell types in the adaptive immune system?

Answer 7

T and B lymphocytes

Question 8

What is the primary role of T-cells?

Answer 8

Antigen recognition, when complexed with an antigen presented by antigen presenting molecules

Question 9

What is the primary role of B-cells?

Answer 9

Produce and Secrete antibodies that recognize soluble and cell surface molecules

Question 10

What immune cells are most responsible for antibody secretion?

Answer 10

Plasma cells, which are the most mature form of B cell

Question 11

What is a plasma cell?

Answer 11

The most mature B-cell, responsible for copious antibody production

Question 12

What is an Fv region and where is it located?

Answer 12

The variable fragment of an immunoglobulin that is specific to the antigen. Located in the Fab domain of immunoglobulins.

Question 13

What is an Fc region and what is its function?

Answer 13

The constant region of an immunoglobulin where antibody class and sub class are determined

Question 14

What is the most prevalent immunoglobulin type secreted in response to non-protein antigens?

Answer 14

IgM. IgM is a pentameric antibody that effects complement. IgM is synthesized early in the immune response

Question 15

What is complement and what is it’s function?

Answer 15

Blood component with enzymatic properties, Results in opsonization and is recognized by complement receptors on macrophages, monocytes, neutrophils, and dendritic cells with subsequent activation of the cells leading to phagocytosis and killing.

Additionally, complement can form a membrane attack complex, resulting in complement dependent cytotoxicity.

Complement is a system of plasma proteins that can be activated directly by pathogens or indirectly by pathogen-bound antibody, leading to a cascade of reactions that occurs on the surface of pathogens and generates active components with various effector functions.

3 main functions:
1) the activation of inflammation
2) the opsonization (labeling) of pathogens and cells for clearance/destruction
3) the direct killing of target cells/microbes by lysis

Question 16

What are the most effective antigen presenting cells?

Answer 16

Dendritic cells

Question 17

What are mechanisms of immune escape?

Answer 17

Down regulation of MHC, tumor antigen loss, stimulation of inhibitory receptors on T cells (CTLA-4, PD1, LAG3), tumor overproduction of indoleamine 2,3-dioxygenase, increased tumor infiltration by regulatory T cells and NKT cells that inhibit immune destruction.

Question 18

Antigen presenting cells with MHC class I molecules complex with what type of immune cells?

Answer 18

CD8+, cytotoxic T cells (these cells kill infected or tumor cells).

Question 19

Antigen presenting cells with MHC class II molecules complex with what type of immune cells?

Answer 19

CD4+, Helper T cells, which produce chemokines and cytokines to help recruit and orchestrate other immune system components.

Question 20

What is the role of CD8+T cells?

Answer 20

Cytotoxic

Question 21

Which lymphocytes can induce apoptosis? By what pathway is this accomplished?

Answer 21

CD8+ T lymphocytes; accomplished via FAS pathway

Fas cell signaling pathway has a central role in the physiological regulation of programmed cell death (also called apoptosis)

This is the EXTRINSIC apoptotic pathway

Question 22

What is Fas?

Answer 22

Cell-surface protein responsible for initiating a cascade of proteases (caspases) culminating in apoptotic cell death. belongs to the subgroup of the tumor necrosis factor receptor (TNF-R) family that contain an intra-cellular ‘death domain’ and can trigger apoptosis

Question 23

What substances are secreted by Th1 CD4+ Cells?

Answer 23

Interferon-gamma, which activates cytotoxic T cells and macrophages for cellular immune responses.

Question 24

What substances are secreted by Th2 CD4+ Cells?

Answer 24

Interleukin-4, which favors antibody responses

Question 25

What is the function of Interferon-gamma?

Answer 25

activation of cytotoxic T cells and macrophages for cellular immune responses.

Question 26

What is the function of IL-2?

Answer 26

T cell growth factor that induces CD4+ T cell expansion. Plays a critical role in maintaining regulatory T cell pool. Some answers from study guides indicate also stimulates CTLs(think this is w IL12

Question 27

What are the functions of IL-12?

Answer 27

1. Induces interferon gamma. 2. Together with IL-2, activates cytotoxic T lymphocytes and NK cells. 3. Initiates differentiation of helper T cells to the Th1 phenotype.

Question 28

What is the function of IL-4 and IL-10?

Answer 28

Meditate development of Th2 Cell, which promote humoral immunity

Question 29

What Cells are CD 34 positive?

Answer 29

Hematopoietic stem cells

Question 30

What cells are CD3 positive?

Answer 30

All T cells.

Question 31

What cells are CD56 positive?

Answer 31

NK cells

Question 32

Once T cells are activated by dendritic cells they gain a variety of functions. What are their most important functions?

Answer 32

Dendritic cells activate T cells (CD4+ and CD8+), which then differentiate to TH1 and TH2. CD8+ cells - cytotoxic T cells CD4+ cells - TH1 cells - secrete IFN-gamma, which activates cytotoxic T cells and macrophages for cellular immune responses TH2 cells - secrete IL-4, which stimulates antibody response

Question 33

What are NKT cells?

Answer 33

Bridge between innate and adaptive immunity They share physical and functional characteristics of NK and T cells Activated NKT cells produce large quantities of cytokines to help differentiation in maturation of other immune cells Decreased function of NKT cells is associated with autoimmune diseases and tumor cell progression

Question 34

What functions do T cells gain after activation by dendritic cells?

Answer 34

Activated T cells carry out effector functions - helper Ts produce chemokines and cytokines to recruit and orchestrate other components of the immune system -Cytotoxic Ts are able to kill target cells by apoptosis (one method is release of cytotoxic granules) Notes say: Creation of cytokines and cytotoxins