Tregs imprint an early immunotolerant tumor environment that prevents effective antitumor immune responses. Using transcriptomics of tumor tissues, we identified early upregulation of VEGF and TGF-β pathways compatible with tolerance imprinting. Silencing of VEGF or TGF-β in tumor cells induced early and pleiotropic modulation of immune-related transcriptome signatures in tumor tissues. These were surprisingly similar for both silenced tumors and related to common downstream effects on Tregs. Silencing of VEGF or TGF-β resulted in dramatically delayed tumor growth, associated with decreased Tregs and myeloid-derived suppressor cells and increased effector T cell activation in tumor infiltrates. Strikingly, co-silencing of TGF-β and VEGF led to a substantial spontaneous tumor eradication rate and the combination of their respective inhibitory drugs was synergistic. VEGF and/or TGF-β silencing also restored tumor sensitivity to tumor-specific cell therapies and markedly improved the efficacy of anti–PD-1/anti–CTLA-4 treatment. Thus, TGF-β and VEGF cooperatively control the tolerant environment of tumors and are targets for improved cancer immunotherapies.
Tristan Courau, Djamel Nehar-Belaid, Laura Florez, Béatrice Levacher, Thomas Vazquez, Faustine Brimaud, Bertrand Bellier, David Klatzmann
Guidelines: The Editorial Board will only consider letters that we deem relevant and of interest to our readers. We will not post data that have not been subjected to peer review, nor will we post letters that are essentially a reiteration of another letter. All accepted letters will be posted on our website within one week of acceptance. We reserve the right to edit any letter for length, content, and clarity. Authors of all accepted letters will be asked to preview any changes. Authors will be notified by e-mail if their letters were not accepted. As this is a final decision, no appeals will be considered.
Specific requirements: All letters must be 400 words or fewer. You may enter the letter as plain text or HTML. The author's name and e-mail address are required, and will be posted with the letter. All possible conflicts of interest must be noted, even if they are not posted. If you wish to include a figure (keep in mind that non-peer-reviewed data will not be posted), please contact the editors directly at firstname.lastname@example.org.