Immune 4

Question 1

What are lymphocytes? (3 types)

Answer 1

a type of leukocyte

• Natural killer cells
• T cells
• B cells

Question 2

Natural killer cells have a what immunity

Answer 2

innate immunity

Question 3

T cells have what immunity

Answer 3

cell mediated immunity

Question 4

B cells have what immunity

Answer 4

humoral immunity

humoral means blood B for blood cells

Question 5

What do NK cells function as?

Answer 5

• protect against viral infections and some cancers

- fast

Question 6

What are the 3 roles of NK cells on targets?

Answer 6

1. cell to cell contact DESTROY
2. release interferons (IFN) and cytokines to WARN other cells
3. release IFN an cytokines to ENHANCE immune response of other cells

Question 7

What does a APC do in response to an antigen?

Answer 7

• encounters antigen
• engulfs
• processes
• presents antigen with the MHC II antigen on the cell surface

Question 8

What does the T cell recognize?

Answer 8

• recognizes the antigen presented on the APC (antigen presenting cell) in association with MHCII

Question 9

MHC class II cells are found mostly on what types of cells?

Answer 9

• B cells
• dendritic cells
• macrophages

Question 10

How do helper T cells respond to if it encounters a target?

Answer 10

• CD4 (helper T cell) encounters foreign antigen fragment on MHC on APC
• helper T cells secrete cytokines to enhance immune response

Question 11

Where does the initial priming of helper T cell lymophocytes occur?

Answer 11

prime to antigen in lymph tissues (spleen lymph nodes tonsils, gut)

Question 12

How are antibodies made and memory cells made with the help of helper T cells?

Answer 12

• helper T cells, activated by APC
• activated helper T binds B cell
• B cell proliferates and differentiates
• memory cell (for innante immunity)
• antibody production

Question 13

MHCII is to helper T cells as MHCI is to ____

Answer 13

cytotoxic T cells

Question 14

Difference between MHCII and MHCI

Answer 14

• MHCII are on macrophages, B cells, and dendritic cells
• MHCI are on all nucleated cells
  MHCII - helper T cells
  MHCI - recognized by cytotoxic T cells

Question 15

What does cytotoxic T cell (CD8) do?

Answer 15

encounters foreign antigen on MHC

• recognize
• T cell activated
• effector cytotoxic T will target and kill it
• while memory cells are created from proliferation of activated cytotoxic T

Question 16

How do cytotoxic T cells actually “kill” other cells?

Answer 16

• activated
• release perforin
• forms pores (perforin channels)
• release granzymes through perforin channels
• granzymes set off apoptosis
• activate FAS death receptor

Question 17

What is the clonal selection theory?

Answer 17

at birth there are lots of B cells

- each Bcell produces on type of antigen but naive until exposure to antigen to stimulate clonal division

Question 18

Humoral B cell immunity phase one

Answer 18

Primary Phase: clonal expansion

• some short lived effector - produce antibodies
• other memory continue to reproduce

Question 19

Humoral B cell immunity phase two

Answer 19

Secondary Phase: memory cells

• only memory cells persists
• when reexposed to antigen (appropriate one)
• memory cells rapidly expand and produce more effector and memory cells (divide again)

Question 20

What do the effector cells of B lymphocytes immunity produce?

Answer 20

• produce antibodies!

Question 21

Explain the B Lymphocyte response in regards to speed and strength of response

Answer 21

Primary
1st exposure to antigen
- slower
- weaker
- produce IgM (memory) antibodies
Secondary
- lymphocyte clones and memory cells
- faster
- stronger
IgG antibodies

Question 22

Allergies are abnormal response of B cells

Answer 22

• immediate hypersensitivity

- eliciting IgE Ab instead of IgG Ab

Question 23

Allergies are abnormal response of T cells

Answer 23

• delayed hypersensitivity

- reaction mediated by lymphokines not Ab