The Histological Characterizations of Dendritic Cell and T-cell Interactions within the Context of Pancreatic Adenocarcinoma

1. The Histological Characterizations of
Dendritic Cell and T-lymphocyte
Interactions within the context of
Pancreatic Adenocarcinoma
Anjlee Panjwani
Dr. George Miller and Rocky Barilla
New York University Medical Center

2. 2
Introduction
•Pancreatic adenocarcinoma (PDAC) is the fourth leading cause of
cancer death in the United States
•Marked by genomic instability, but also a target for cancer
therapeutics
•Portrayed by an infiltrate of leukocytes
•Reveal an alternate immune response through immunoediting
•DC’s arise from a hematopoetic lineage playing diverse roles in T-cell
regulation and activation
•Dendritic Cells (DC) can be shown to induce tolerance and activate
naive T-cells by presenting its antigen
•Express high levels of the MHCII molecule and CD11c+ integrin

3. Function of Dendritic Cells: T-cell Activation
DC naive
T-cell
Th1 cell
Th2 cell
T
regulatory
cell
On the figure to the right,
the DC’s present their antigen
to the naive T-cells in order to
activate them. As it can be
seen, the DC’s can favor a
different response by
the T-cells they activate,
whether it is a Th1 response
or a Th2 response.

4. 4
Question
How can we reveal the behavior of dendritic cells
interacting with other leukocytes and other types
of cells in the context of pancreatic
adenocarcinoma?

5. 5
Goals
•To make observations regarding the locations of dendritic cells
relative to T-lymphocytes and other leukocytes that are present in
lymphoid tissue
•Through these observations, there can be many suggestions
regarding the dynamics of DC interactions and the type of
effector responses that may be elicited by the DC. T
•To make conclusions regarding morphology (shapes and sizes of
cells) and quantity of DC
•Suggest much about the cell’s activation state and possibly
elucidate the current boundaries to DC-T cell mediated
therapies for pancreatic cancer.

6. 6
Materials and Methods
FC1242 cells were injected into the pancreas of the mouse. After 8-10
weeks, the spleen was harvested, fixed, and flash-frozen in a liquid
nitrogen bath after being inserted in OCT media. Tissue were then
sent
to the CryoStat for frozen slides

7. Materials and Methods: Immunohistochemistry
An
immunohistochemistry
was conducted on the
frozen spleen tissue.
Antigen retrieval was
done with Proteinase K,
and the slides were
blocked using 10% goat
serum, H202, and
avidin/streptavidin
blocking kit. Slides were
washed in Tris Buffered
Saline with .1% tween.

8. 8
Figure 1. There was an elevated number of
CD11c+ dendritic cells in the pancreatic
cancer model

9. Figure 1a. There is an elevated number of CD11c+
dendritic cells in the spleen of FC1242-pancreatic cancer-
bearing mice as compared to the spleen of non-tumor
bearing mice.

10. Figure 1b. Elevated number of CD11c+ DC were
observed in the peri-follicular region
• Elevated number of CD11c+
DC in the spleen tissue
overall
• Normally, CD11c+ are seen
around areas in which the T-
cells congregate
• DCs were observed around
the follicular (B-cell) regions
of the tissue

11. 11
Results
•Cells expressing the antigen CD11c+ were counted in 5-10 40x high
power fields (HPF) on each biological replicate/specimen, and averaged
(Figure 1B).
•There were a greater amount of cells (avg= 369.67) compared to the non-
tumor bearing spleen model (avg=221.1) (Figure 1B)
•Observed CD11c+ cells were expressed in larger quantity in marginal
zones and around the B cell follicles (Figure 1A). Cells in the non-
tumor bearing spleen (sham- control) were seen to have a smaller
average of dendritic cells in both extra-follicular (avg=174.6) and
perifollicular regions (avg= 46.5).
•In the tumor-bearing spleen, there was an average of 279.67 in the
perifollicular regions and an average of 90 extra-follicular regions(Figure
1C).

12. Figure 2. Spleen-infiltrating DC of
tumor-bearing mice congregate with
invading pancreatic tumor cells

13. Figure 2a. Immunofluorescence on spleen tissue
expressing CD11c (green) and CK19 (red).

14. Figure 2b. Invasive cancer IHC with CD11c
(Magenta) and CK19 (brown).

15. 15
Results
•Invading cancer cells, represented by CK19 staining, as well as DC
were observed in contact or close proximity to one another,
•Especially around the arterioles of the spleen where afferent blood
flow, naive T cells, and activated DC normally enter the spleen.
•The cancer cells began to form ductal structures, which is typical of
PDAC cells, and also known as a more “differentiated” state (Figure
2B);
•there was also many mesenchymal tumor cells (Figure 2B, arrow) that
were not in ductal structures but had enlarged nuclei that were
misshapen, indicating genomic instability.
•“macro-metastases” seem to intermingle with dendritic cells entering
the spleen (Figure 2A)

16. DISCUSSION
● Possible that the DC-tumor interaction is preventing DCs to activate T-
cells successfully
● The mesenchymal morphology suggests that there may be cancer cells
are infiltrating the spleen in the cancer model
● Future Research Questions
○ Role of various dendritic cell subsets such as CD103+ DC with
other leukocytes (T-lymphocytes and B-lymphocytes)
○ Confirmation of DCs interacting with the humoral immune system
○ May be worth exploring the tumor cell interactions with other
types of cells to determine if the tumor interfacing is observed
only with the dendritic cell

17. 17
Acknowledgments
Rocky Barilla and Dr. George Miller, MD, Ph.D
Research Fellow and Principle Investigator
NYU Langone Medical Center Dept. of Surgery and Cell Biology
Dr. JoAnn Gensert
Senior Research Biology Instructor
The Bronx High School of Science