In vivo discovery of immunotherapy targets in the tumour microenvironment.
Recent clinical trials showed that targeting of inhibitory receptors on T cells induces durable responses in a subset of cancer patients, despite advanced disease. However, the regulatory switches controlling T-cell function in immunosuppressive tumours are not well understood. Here we show that such inhibitory mechanisms can be systematically discovered in the tumour microenvironment. We devised an in vivo pooled short hairpin RNA (shRNA) screen in which shRNAs targeting negative regulators became highly enriched in murine tumours by releasing a block on T-cell proliferation upon tumour antigen recognition. Such shRNAs were identified by deep sequencing of the shRNA cassette from T cells infiltrating tumour or control tissues. One of the target genes was Ppp2r2d, a regulatory subunit of the PP2A phosphatase family. In tumours, Ppp2r2d knockdown inhibited T-cell apoptosis and enhanced T-cell proliferation as well as cytokine production. Key regulators of immune function can therefore be discovered in relevant tissue microenvironments.
1] Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA [2].
Penghui
P
Zhou
1] Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA [2] [3] Jounce Therapeutics, Cambridge, Massachusetts 02138, USA.
Donald R
DR
Shaffer
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Diana A
DA
Alvarez Arias
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Yukoh
Y
Nakazaki
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Wouter
W
Pos
David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA.
Alexis J
AJ
Torres
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Viviana
V
Cremasco
Whitehead Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA.
Stephanie K
SK
Dougan
Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA.
Glenn S
GS
Cowley
1] Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA [2] Jounce Therapeutics, Cambridge, Massachusetts 02138, USA.
Kutlu
K
Elpek
Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, USA.
Jennifer
J
Brogdon
Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, USA.
John
J
Lamb
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Shannon J
SJ
Turley
Whitehead Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA.
Hidde L
HL
Ploegh
Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA.
David E
DE
Root
David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA.
J Christopher
JC
Love
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Glenn
G
Dranoff
Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA.
Nir
N
Hacohen
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Harvey
H
Cantor
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Kai W
KW
Wucherpfennig
D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology; D017209:Apoptosis / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D049109:Cell Proliferation; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D005260:Female; D055785:Gene Knockdown Techniques; D059014:High-Throughput Nucleotide Sequencing; D007167:Immunotherapy / Q000379:methods; D016246:Lymphocytes, Tumor-Infiltrating / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008546:Melanoma, Experimental / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D058990:Molecular Targeted Therapy; D054648:Protein Phosphatase 2 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D015203:Reproducibility of Results; D059016:Tumor Microenvironment / Q000276:immunology*
D000951:Antigens, Neoplasm; D016207:Cytokines; D034741:RNA, Small Interfering; C586425:Ppp2r2d protein, mouse; D054648:Protein Phosphatase 2