Lecture 13

Question 1

What does MHC stand for

Answer 1

Major Histocompatibility complex

Question 2

What does the MHC do

Answer 2

Marks are protein expressed on surface of cell

Question 3

What can the MHC label body cells as

Answer 3

Labels body cell as self or “friend”

Labels cells as for

Question 4

What happens if the MHC labels a self of friend cell

Answer 4

Cell used for immune responses of self - causing support

Question 5

What happens if the MHC labels a foe cell

Answer 5

MHC places piece of invader on surface with self marker

Question 6

What are the 4 steps of MHC attacks

Answer 6

1) Threat
2) Detection
3) Alert
4) Alarm

Question 7

Explain the “threat” and “detection” stops of MHC attacks

Answer 7

Threat
– Invader enters body

Detection:
– Macrophage encounters, engulfs, and digits invader
– Macrophage places piece of invader (antigen) on surface with MHC marker

Question 8

Explain the “alert” and “alarm” stops of MHC attacks

Answer 8

Alert:
– Macrophage presents antigen helper T cell that secretes chemical called helper T cell

Alarm:
– Effector T cell breaks into Naive cytotoxic T-cell and Naive B cell

Question 9

What are the 2 signals involved in T cell secretion

Answer 9

1) Recognition
2) Verification - Must be sure it is responding to non self

Question 10

Compare a naive cytotoxic T-cell vs naive B cell

Answer 10

Naive cytotoxic T-cell: cell-mediated response

Naive B cell: antibody-mediated response

Question 11

Explain the the 3 steps involved in the T cell route of MHC

Answer 11

5) Building defenses
– Naive T cell breaks into effector cytotoxic T cell and memory cytotoxic T-cell

6) Defense - effector cytotoxic T cell
– Find cells displaying foreign antigen and kill them with perforins (punch holes in target cell membrane)

7) Memory - memory cytotoxic T-cell
– Stored for continued surveillance

Question 12

Explain the the 2 steps involved in the B cell route of MHC

Answer 12

5) Building specific defenses
– Cell divides to plasma cell
Amplification

6) Defense - Effector cytotoxic B cell
– Cell secretes antibodies

Question 13

What are the 3 types of memory cells

Answer 13

Memory helper T cells
Memory cytotoxic t cells
Memory B cells

Question 14

Where are memory cells stored

Answer 14

Stored in bone marrow and thymus for lifetime

Question 15

Why are memory cells useful

Answer 15

They provide quicker and more robust response in subsequent encounters

Question 16

What feedback system are T supressor cells apart of

Answer 16

Negative Feedback System

Question 17

What do T-suppressor cells do

Answer 17

T-suppressor cells suppress activation of the immune system, particularly production of T helper cells

Question 18

Why are T supressor cells important

Answer 18

Important for allowing tolerance to self-antigens

Question 19

What happens if there is too little T-suppressor response

Answer 19

Association with autoimmune disease, allergies, graft rejection, inflammatory bowel disease

Question 20

What happens if there is too much T-suppressor response

Answer 20

Possible connection to cancer, increased incidence of infectious diseases