Lecture 5: Effector and memory T cells
1) What are the three steps requires for the activation of Cytotoxic T lymphocytes (CTL or
and CD8 response)?
2) How does the Licensing of the APC occur? What is their role?
3) How does activation of CTL occur as describe by Squentional theory?
4) How does activation of CTL occur as describe by simultanous theory?
5) What is the best cell to be and licenced APC?
6) When the DC activates a CD4 and CD8 T cells, what types of T cells can each of these
7) Summarize the activation of T cells by DC ? ( 3 quick steps)
8) Comparison of the naïve vs effector T cells: Costimulatory signal ( CD28B7 is it
required)? Cell adhesion molecules ( CD2 + LFAA1 levels? Trafficking pattern ( i.e.
where they are found)?
9) What are homing receptors?
10)Effector T cells express what receptor that draw them into various tissues?
11) A CD4 T cells when it proliferates and differentiates what are the four different T cells it
can differentiate to? What are their roles and cytokines associated with 2 of them?
12) How does Th1 response (intra) activates an macrophage?
13)How TH1 are very important for clearing bacteria that replicate inside macrophages?
What bacteria infection is a prime example of this?
14) Explain what is Th2 response involved in? How does it stimulate the IgE production?
( explain the step)
15) what are the effect of producing IgE?
16)Th2 and alternative activation: what happens if the TH2 releases Il13 as well as Il4?
17) Now that we have a mature CTL: what does it start making? What does it start doing?
18)How does as CTL induce death? Is CD28 (costimulatory signal) required?
19)Specific details of death: in the granules that are released what are perforin for? what are
granzymes for? when exactly are these granules released ( what ions increases)?
20)Once indies what does granzyme do?
21) How is CTL protected even though porforin is really bad for target?
22) How is Fas Ligand ( for apoptosis) used by CTL to kill?
23) Explain the curve of primary and secondary response? Why this difference?
24) What is required for the survival of the memory T cells?
25)Do memory t cell require DC? What are the two form of memory T cells and the
difference between them?
26) To distinguish them: CD44 and CD62L (Lselecting) and CCR7 (also adhesion) which
are found on the naïve, memory and effector T cells?
27) Explain difference btw Naïve, effector and memory T cell?
1) Signal from TCR after recognition of Ag + MHCI on a “licenced” APC ▯Co
stimulatory signal (CD28B7) ▯and Activation of high affinity IL2R by IL2 from Th1
or Th17 Lecture 5: Effector and memory T cells
2) CD40 on APC interacts with CD40L on Th cell▯ M icrobial products attach to the Toll
like receptor activation making this an licensed APC that is the only one that can then go
on to activate CTL response.
3) Sequentional theory: states that the Th1 or Th17 bind the NON licensed APC using
MHC II ▯make this a licensed APC now ▯ which then go and bind na ïve CTL using MHC
I receptor ▯ and also produce its our Il2 and stimulate the CTL.
4) Simultaneous: the APC has both the MHC I and II that are expressed> it uses MHC II to
bind the Th1/17 and becomes a licensed ( need other thing as well) ▯ at the same time it is
also bonded to Naïve CD8+ T cell using MHC I and activates it( also the Il12 seems to
come from the Th1/17 cell)
5) Dendritic cells (to be a licensed you have to present both MHC I and II and do cross
6) CD4D ▯ C▯activated ▯ can become follicular T cells where they help na ïve B cells become
activated in the lymph nodes. Also they can become Th1 (intracellular fight such as
macrophages) and Th2 (extracellular such as mast/esonophiles cells)) or Th17
(inflammation such as neutrophils response). The CD8a ▯ ctivated▯proliferates right away ▯
and become CTL and kills virus infected intracellular cells.
7) Dendritic cell priming of naïve T cells in lymph node ▯ Proliferation and differentiation of
naïve T cells to effector cells in the secondary lymphoid organs ▯ Migration of effector
cells from nodes to tissue site of infection
8) Effector cells: Costimulatory signal ( CD28B7) NOT required. Cell adhesion molecules
(CD2 + LFAA1) levels are very high so they can bind bad tissues. Most stay in tertiary
lymphoid tissues or major inflammatory sites. Naïve T cells ▯require signal, adhesion
receptor level very low ( want them to move around) and found near HEV.
9) Effector T cells have homing receptors to endothelium that are activated