Cell Mediated Immunity

Question 1

What is cell mediated immunity?

Answer 1

Immunity provided by cytotoxic T cells and by T helper cell mediated activation of macrophages. Required to defeat intracellular pathogens, which are hidden from the effects of antibodies; complementary

Question 2

What are the 2 types of T cells that have different T cell receptors?

Answer 2

α-beta T cell and gamma-delta T cell

Question 3

What does the α-beta T cell recognize?

Answer 3

Peptides presented by MHC molecules

Question 4

What does the gamma delta T cell recognize?

Answer 4

Antigens alone, lipoprotein and glycolipids presented by MHC like molecule CD1

Question 5

Give the differences between types of alpha-beta T cells.

Answer 5

CD4 on cell surface: Th1, Th2, Th17, Tfh, Treg

CD8 on cell surface:
Tc

Question 6

Give the primary functions of the following: Th1, Th2, Th17, Tfh, Treg

Answer 6

Th1: help CTL and macrophages, inhibit Th2
Th2: hello B cells, inhibit Th1
Th17: promote inflammation
Tfh: help germinal center B cells 
Treg: suppress immune responses

Question 7

Give the function of Tc

Answer 7

Kill infected cells

Question 8

What do Th1 cells characteristically secrete?

Answer 8

IFNy

Question 9

What crucial role do dendritic cells play in the differentiation of a ThO T cell?

Answer 9

Dendritic cells release cytokines in response to PAMPs- these cytokines influence the maturation of the ThO cell into the appropriate T cell lineage

Question 10

What do intraepithelial lymphocytes characteristically have on their cell surface?

Answer 10

CD8αα

Question 11

A theoretical tumor cell is immune to the membrane protein performing. What would this mean for the function of cytotoxic T cells?

Answer 11

Cytotoxic T cell mediated apoptosis is dependent on Fas and FasL interaction

Question 12

How is the location of phosphatidylserine on cells important to immune function?

Answer 12

A healthy cell has internal phosphatidylserine, external phosphatidylserine signals to macrophages to phagocytose the cell

Question 13

What are cytokines and what are the main groups of cytokines?

Answer 13

Small (8-80kDa) secreted proteins that act as messengers between cells 
Main groups are:
Interleukins
Colony-stimulating factors
Chemokines
Interferons
Tumor necrosis factors

Question 14

What are the two main types of interferons?

Answer 14

Interferons: inhibition of viral replication

Type 1: IFNα and IFNbeta
Produced by most nucleated cells of body

Type 2: IFNgamma
Produced by NK cells, Th1 cells and Tc1 cells
Increases MHC class 1 and 2 expression

Question 15

What are the 3 main types of colony stimulating factors?

Answer 15

1. Granulocyte-macrophage-colony-stimulating factor (GM-CSF)
2. Monocyte/macrophage colony-stimulating factor (M-CSF)
3. Granulocyte colony-stimulating factor (G-CSF)

Question 16

A patient was found to be unable to defend against viruses in their system. It was determined that the patients immune system was able to halt viral replication at mucosal surfaces but viral replication occurred unchecked otherwise. Which cytokine would you expect to be dangerously low in this patient?

Answer 16

IFNgamma

Question 17

What cytokine may be responsible if a patient was found to have a high level of monocytes which were differentiating at a dangerously slow rate?

Answer 17

M-CSF

Question 18

What are the two types of tumor necrosis factors?

Answer 18

TNFα and TNFbeta (lymphotoxin)

Question 19

What are the types of functional modes of cytokines?

Answer 19

Autocrine: a lymphocyte produces a cytokine and also has the receptor for it
Paracrine:one cell produces a cytokine and a different cell responds to it

Question 20

Which cytokine is often targeted in the treatment of rheumatoid arthritis?

Answer 20

TNFα