Enhancement Of T-Cell Immunity To Osteosarcoma By Modulation Of
Programmed Death Receptor Pathway
Pooja Hingorani, Danielle Lussier, Joseph Blattman
Overview
• T cell tolerance and immune inhibitory pathways in osteosarcoma
• Review our data
Immune tolerance in osteosarcoma
• Loss of Class I HLA expression in osteosarcoma tumors related to worse overall survival*
• CTLA4 polymorphisms are associated with higher risk of developing osteosarcoma**
• Metastatic osteosarcoma expresses T cell Ig/mucin molecule 3 (TIM3), which in other tumor settings inhibits the function of infiltrating CTL, leading to tumor progression #
• B7-H3 expression, a co-inhibitory protein involved in tumor immune escape from T cells, inversely correlates with CTL infiltration in human osteosarcoma, and is indicative of poor prognosis in osteosarcoma patients @
*Tshukahara et al., Cancer Sci 2006; **Liu et al, DNA Cell Bio 2011; #Shang et al., Oncol Lett 2013; @ Wang et al., Plos One 2013
Relative expression of PDL1 in osteosarcoma
Shen J K et al. Cancer Immunol Res 2014;2:690-698
©2014 by American Association for Cancer Research
Overall survival of 37 patients with osteosarcoma in relation to PDL1 gene expression.
Shen J K et al. Cancer Immunol Res 2014;2:690-698
©2014 by American Association for Cancer Research
Characterization of the origins of metastases.
Shen J K et al. Cancer Immunol Res 2014;2:690-698
©2014 by American Association for Cancer Research
Specific Aims• Evaluate expression of PD-L1 on tumor cells and PD-1 on TILs in patient
samples and metastatic osteosarcoma cell line (in vitro and in vivo)• Evaluate the functional ability of TILs infiltrating metastatic tumors• Evaluate the effect of PD-L1 blockade on development and progression of
pulmonary metastases in vivo• Evaluate the effect of combinational therapies (PD-L1 antibody +
chemotherapy; PD-L1 antibody + ipilimumab)
PD-L1 is expressed in human metastatic osteosarcoma
50um
50um50um
50um
Isotype
Metastatic Osteosarcoma
PD-L1
Primary Osteosarcoma50um
50um50um
50um
12/ 16 (75% ) of metastatic tumors had some PD-L1 expression
PD-1 is expressed on human metastatic TILs
50um
50um50um
50um 50um
50um50um
50um
50um
50um
Isotype
PD-1
50um
50um
50um
50um
Metastatic Osteosarcoma Primary Osteosarcoma
-13/16 (81%) of metastatic tumors had PD-1+ TILs-In 11/16 (70%) metastatic tumors, PD-1 expression on TILs correlated with PD-L1 expression on tumor cells
PD-L1 expression is increased in K7M2 osteosarcoma cells
PD-L1
% o
f Max
imum
40731848
Pre Implantation Post Tumor
30%
TILs from lung metastases are PD-1+
%PD
1+
SPLEEN CD8 TIL CD8
*
CD8
PD-1
SPLEEN TIL
94%
6% 87%
13%
Isotype
PD1
Healthy Lung
Late Disease Lung
Early Disease Lung 50 µm50 µm 50 µm
50 µm 50 µm 50 µm50 µm
TILs are functionally impaired in the presence of tumor cells
**
%IF
Nγ+
*
*
*
- + - + AgPD-L1+ K7M2
PD-L1- 4T1
%TN
F+
*
**
- + - + AgPD-L1+ K7M2
PD-L1- 4T1
%IL
-2+
**
- + - + AgPD-L1+ K7M2
PD-L1- 4T1
%IF
Nγ+
Control PD-L1 Ab
**
%TN
F+
**
*
Control PD-L1 Ab
%IL
-2+
**
*
Control PD-L1 Ab
A.
B.
C.PD-L1 blockade restores function to TILs
Blockade of PD-1:PD-L1 significantly enhances survival in metastatic osteosarcoma model
Days post implant
Perc
ent S
urvi
val
P=0.0005
30 day PD-L1 antibody treatment does not significantly improve survival compared to 15 day treatment
Is immune escape occurring?
PD-L1 antibody treatment changes inhibitory receptor expression
* *
PD-L1 antibody treated osteosarcoma is resistant to additional treatment when injected into naïve mice.
PD-L1
% o
f Max
imum
*
Combinational PD-L1 antibody treatment coupled with conventional chemotherapy
The combination improves survival as compared to chemotherapy alone but is similar to PD-L1 antibody alone.
Combinational PD-L1 antibody coupled with CTLA-4 antibody treatment improves survival
In conclusion
• PD-1/PD-L1 interaction induces immune tolerance in metastatic osteosarcoma
• PD-L1 blockade improves survival but not 100%• Resistance to therapy develops by up-regulation of alternative
immune escape pathways • Combinational immune therapies may have the highest
impact on disease control in metastatic osteosarcoma
• Joseph Blattman• Danielle Lussier• John Johnson• Lauren O’Neill• Lizbeth Nieves• Megan McAfee• Susan Holechek
• Paul Dickman• Patients and families
Acknowledgements