Lecture 39+40

Question 1

antigen specific cells

Answer 1

T-helper (CD4)

T-cytotoxic (CD8)

Question 2

antigen non-specific cells

Answer 2

NK cells
macrophages
neutrophils
eosinophils

Question 3

functions of cell mediated immunity

Answer 3

response to intracellular/phagocytized pathogens
activation of M1 macrophages
induce B cells to class switch (igG) to opsonize (INF gamma)
direct killing

Question 4

function of M1 macrophage

Answer 4

activated by IFN gamma, LPS, etc

pro-inflammatory
Th1 response
antigen presentation ability
killing of intracellular pathogens

Question 5

function of the M2 macrophage

Answer 5

activated by IL-4, IL-13, IL-10, TGF beta

functions: 
anti-inflammatory 
clearance of parasites 
tumor promotion 
Th2 response 
immunoregulation 
tissue remodel and angiogenesis

Question 6

antigen recognition

Answer 6

TCR will recognize peptide on the APC

CD4 or CD8 coreceptors will recognize the MHC molecule

T cell activation are triggered by the co stimulator proteins linked to TCR and CD

adhesion molecules strengthen the binding between T cells and APC

Question 7

B7 molecules (CD80) B7-2 (CD86)

Answer 7

co-stimulator

expression increases in APCs when antigen encounter
guarantees response to foreign molecules

recognized by CD28 receptor

CD28/B7 signaling is essential for the response of naïve T cells!!!

Question 8

the importance of the CD40 ligand

Answer 8

instead of activating T cells, they activate APCs
to express more B7 costimulators and to
secrete cytokines (e.g.,IL-12) to enhance T cell
differentiation

Question 9

Agents that block B7:CD28

Answer 9

are used in the treat RA

Question 10

Antibodies to CD40:CD40L

Answer 10

interactions are being tested for graft rejection

Question 11

Antibodies that block CTLA-4 or PD-1

Answer 11

to the enhance the immune response in cancer patient

Question 12

The response to T lymphocytes

Answer 12

secretion of cytokines an expression of cytokine receptors

first cytokine: CD4 T cells - IL-2

autocrine signal for proliferation, diff, and survival

Question 13

CTL and HIV

Answer 13

HIV kills the CD4 cells and not the CD8 cells

The requirement of helper T cells in CD8+ is likely
explanation for defective CTL responses of viruses in
HIV patients

Question 14

conjugate formation for CTL killing

Answer 14

Cell adhesion (LFA-1 on CTL binds ICAM on target cell)

Recognition of MHC I: Ag on target cell

Question 15

membrane attack for CTL killing

Answer 15

the granules: perforin and granzymes

Question 16

7 criteria for determining responsibilities

Answer 16

1. expertise
2. proximity
3. effectiveness
4. lower risk/cost
5. unique
6. severity
7. public trust