In vivo discovery of immunotherapy targets in the tumour microenvironment.

Nature
Authors
Keywords
Abstract

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.

Year of Publication
2014
Journal
Nature
Volume
506
Issue
7486
Pages
52-7
Date Published
2014 Feb 06
ISSN
1476-4687
URL
DOI
10.1038/nature12988
PubMed ID
24476824
PubMed Central ID
PMC4052214
Links
Grant list
T32 AI007386 / AI / NIAID NIH HHS / United States
R01 CA173750 / CA / NCI NIH HHS / United States
P30 CA014051 / CA / NCI NIH HHS / United States
DP3 DK097681 / DK / NIDDK NIH HHS / United States
P30-CA14051 / CA / NCI NIH HHS / United States
1R01CA173750 / CA / NCI NIH HHS / United States
P01 AI045757 / AI / NIAID NIH HHS / United States
T32 AI07386 / AI / NIAID NIH HHS / United States