The Immune system IV (Lecture 8)

Question 1

What are the three types of T cells?

Answer 1

Helper T cells, Cytotoxic T cells (kill pathogen), and suppressor T cells

Question 2

______ bind antigen within the cell and transport antigen to the surface, where it can be recognized by T cell

Answer 2

MHC molecules

Question 3

Class ______ MHC is on the surface of all nucleated cells whereas class ______ MHC is on the surface of macrophages, activated B cells, activated T cells, and thymus cells.

Answer 3

1, 2

Question 4

True or False: MHC molecules are not associated with tissue or organ rejectio by stimuling immune response to foreign tissue

Answer 4

False, they are

Question 5

Bind with Type ______MHC → cytotoxic T (CD8) cells

Bind with Type ______ MHC → helper T (CD4) cells

Ratio of CD4: CD8 T cells is ~______

Answer 5

1, 2, 2:1

Question 6

True or False: CTLs eliminate cells displaying foreign antigen complexed with class I MHC

Answer 6

True

Question 7

If T cells don;t express either marker (CD4 or CD8) this is known as?

Answer 7

Double megative

Question 8

True or False: Negative selection removes T self with high affinity to self (autoimmune disease).

Answer 8

True

Question 9

True or False: Most cells (90-96%) fail positive selection and fail to receive needed survival signals.

Answer 9

True

Question 10

How does a helper T cell become activated?

Answer 10

Bind to class II MHC–foreign antigen complex on surface of macrophages and B cells

Macrophages and B cells secrete IL-1, which induces proliferation and differentiation of helper T cells

Question 11

______ regulate immune responses to intracellular pathogens

Answer 11

TH1

Question 12

______ secrete IL-17, assist in cell-mediated immunity, help defend against fungi

Answer 12

TH17

Question 13

______ aid with humoral immunity, regulate B-cell development in germinal centres

Answer 13

TFH (follicular helper)

Question 14

______ regulate immune responses to extracellular pathogens

Answer 14

TH2

Question 15

True or False: Some cancers and viruses inhibit production of class I MHC molecules, thereby protecting them from the immune system

Answer 15

True

Question 16

______ are proteins that mediate the effector functions of the immune system

Answer 16

Cytokines

Question 17

______ are a subpopulation of cytokines, that specifically mobilizes immune cells from one organ, or from one part of an organ to another through concentration gradients (chemotaxis).

Answer 17

Chemokines

Question 18

______are a substance that attracts cells by influencing assembly, disassembly and contractility of cytoskeleton proteins, and expression of cell-surface adhesion molecules

Answer 18

Chemoattarctants

Question 19

True or False: Many cytokines are referred to as interleukins and are soluble proteins.

Answer 19

True

Question 20

______ action is released into the bloodstream to affect distant cells

Answer 20

Endocrine

Question 21

______ action is released to affect nearby cells.

Answer 21

Paracrine

Question 22

______ action is released, but then bind to receptors on the cell that produced them

Answer 22

Autocrine

Question 23

______ means that a cytokine induces different biological effects depending on the nature of the target cells

Answer 23

Pleiotropic actions (one has many effects)

Question 24

______ action is when One cytokine inhibits the effects of another cytokine.

Answer 24

Antagonist

Question 25

______ the action of one cytokine on a target cell, induces that cell to produce one or more additional cytokines.

Answer 25

Cascade induction

Question 26

Interleukin 1 = Hemopoietin family = Interferon family = Tumour necrosis factor = Interleukin 17 = Chemokines =

Answer 26

inflammation communication 1st, viral response regulation pro inflammatory response to release and produce cytokines