CH 8 PCB 3233
What are the reasons for the several day delay in a primary response.
Infection à transport to secondary lymphoid tissue à antigen processing and presentation à small initial #
of lymphocytes specific for the antigen à proliferation and differentiation. - correct answer ✔✔Once an
antigen-specific T cell is trapped in the lymph node by an APC and activated it takes several days for the
activated T cell to proliferate and differentiate into effector T cells.
LFA-1, ICAM-1, L-selectin, vascular addressing. Know the homing and cell to cell adhesion slides. - correct
answer ✔✔L-Selectin ( on T cells) interact with vascular addressing on surface of HEV venules(CD34 &
GlyCAM-1)
LFA-1( on T cells) - activated by chemokines it binds to extracellular matrix.
ICAM( on epithelial)-1 Binds to LFA-1
Vascular addressin( on epithelial) - binds to L-selectin
Know the 4 different types of leukocyte adhesion molecules - correct answer ✔✔Selectins - bind
carbohydrates. Initiate leukocyte endothelial interaction.
vascular addressins - Bind to L- selectin. Initiate leukocyte-endothelial interaction
integrins= Bind to cell adhesion molecules and extracllular matrix. Strong adhesion
immunoglobulin super familiy- Cell adhesion. targets for integrins
If a naïve T-cell comes into the lymph node from the blood what does it enter through? Fig. 8.5 - correct
answer ✔✔T-cells that do not encounter their specific antigen leave the lymph node in the efferent
lymph and join the blood stream.
, What is S1P? What does it do? - correct answer ✔✔the T-cells will be drawn out of the lymph node and
continue to recirculate until it meets it's antigen
Know which types of T cells migrate to site of infection after activation and which one stays in the
secondary lymphoid tissues (lymph node) - correct answer ✔✔a. Cytotixic CD8 T cells and CD4 (TH1,
TH2, TH17, Treg) cells → goes to site of infection
b. CD4 TFH cells → stays in the secondary lymphoid tissues
c. CD8 → kills infected cells, CD4 secrete cytokines
What is CTLA-4? What does it bind to and what is the result of it binding? What cell will put up CTLA-4
on its surface? - correct answer ✔✔CTLA-4 binds B7 twentyfold more strongly than does CD28 and
functions as an antagonist.
So B7 binding to CD28 activates a T cell, while B7 binding to CTLA-4 slows down activation and limits cell
proliferation
What chemokine directs the naïve T-cells to the T-cell area to check the dendritic cells MHC molecules? -
correct answer ✔✔CCL21 and CCL19
What happens when a naïve T cell interacts with an antigen presented by a cell that is not a professional
antigen presenting cell - correct answer ✔✔Becomes anergic (no B7 to activate it)
What does a P-APC have that other cells don't have? - correct answer ✔✔MHC class 2 and CD28 proteins
that bind B7 molecules on the APC
Is B7 always produced by dendritic cells? If not, when do they make it? - correct answer ✔✔expression is
a direct consequence of infection, induced by interaction of a potential APC
Langerhan's cells, what and where are they? - correct answer ✔✔Immature dendritic cell with large
granules
Mature Dendritic cells vs. Immature Dendritic cells. What do they do different and what kind of surface
molecules do they have (DEC 205 vs. DC-SIGN)? - correct answer ✔✔Immature DC:
What are the reasons for the several day delay in a primary response.
Infection à transport to secondary lymphoid tissue à antigen processing and presentation à small initial #
of lymphocytes specific for the antigen à proliferation and differentiation. - correct answer ✔✔Once an
antigen-specific T cell is trapped in the lymph node by an APC and activated it takes several days for the
activated T cell to proliferate and differentiate into effector T cells.
LFA-1, ICAM-1, L-selectin, vascular addressing. Know the homing and cell to cell adhesion slides. - correct
answer ✔✔L-Selectin ( on T cells) interact with vascular addressing on surface of HEV venules(CD34 &
GlyCAM-1)
LFA-1( on T cells) - activated by chemokines it binds to extracellular matrix.
ICAM( on epithelial)-1 Binds to LFA-1
Vascular addressin( on epithelial) - binds to L-selectin
Know the 4 different types of leukocyte adhesion molecules - correct answer ✔✔Selectins - bind
carbohydrates. Initiate leukocyte endothelial interaction.
vascular addressins - Bind to L- selectin. Initiate leukocyte-endothelial interaction
integrins= Bind to cell adhesion molecules and extracllular matrix. Strong adhesion
immunoglobulin super familiy- Cell adhesion. targets for integrins
If a naïve T-cell comes into the lymph node from the blood what does it enter through? Fig. 8.5 - correct
answer ✔✔T-cells that do not encounter their specific antigen leave the lymph node in the efferent
lymph and join the blood stream.
, What is S1P? What does it do? - correct answer ✔✔the T-cells will be drawn out of the lymph node and
continue to recirculate until it meets it's antigen
Know which types of T cells migrate to site of infection after activation and which one stays in the
secondary lymphoid tissues (lymph node) - correct answer ✔✔a. Cytotixic CD8 T cells and CD4 (TH1,
TH2, TH17, Treg) cells → goes to site of infection
b. CD4 TFH cells → stays in the secondary lymphoid tissues
c. CD8 → kills infected cells, CD4 secrete cytokines
What is CTLA-4? What does it bind to and what is the result of it binding? What cell will put up CTLA-4
on its surface? - correct answer ✔✔CTLA-4 binds B7 twentyfold more strongly than does CD28 and
functions as an antagonist.
So B7 binding to CD28 activates a T cell, while B7 binding to CTLA-4 slows down activation and limits cell
proliferation
What chemokine directs the naïve T-cells to the T-cell area to check the dendritic cells MHC molecules? -
correct answer ✔✔CCL21 and CCL19
What happens when a naïve T cell interacts with an antigen presented by a cell that is not a professional
antigen presenting cell - correct answer ✔✔Becomes anergic (no B7 to activate it)
What does a P-APC have that other cells don't have? - correct answer ✔✔MHC class 2 and CD28 proteins
that bind B7 molecules on the APC
Is B7 always produced by dendritic cells? If not, when do they make it? - correct answer ✔✔expression is
a direct consequence of infection, induced by interaction of a potential APC
Langerhan's cells, what and where are they? - correct answer ✔✔Immature dendritic cell with large
granules
Mature Dendritic cells vs. Immature Dendritic cells. What do they do different and what kind of surface
molecules do they have (DEC 205 vs. DC-SIGN)? - correct answer ✔✔Immature DC:
