Immunomodulation of the tumor microenvironment is emerging as an important area of research for the treatment of cancer patients. Several synthetic and natural agents are being investigated for their ability to enhance the immunogenic responses of immune cells present in the tumor microenvironment to impede tumor cell growth and dissemination. Among them, resveratrol, a stilbenoid found in red grapes and many other natural sources, has been studied extensively. Importantly, resveratrol has been shown to possess activity against various human diseases, including cancer. Mechanistically, resveratrol has been shown to regulate an array of signaling pathways and processes involving oxidative stress, inflammation, apoptosis, and several anticancer effects. Furthermore, recent research suggests that resveratrol can regulate various cellular signaling events including immune cell regulation, cytokines/chemokines secretion, and the expression of several other immune-related genes. In this review, we have summarized recent findings on resveratrol’s effects on immune regulatory cells and associated signaling in various cancer types. Numerous immunomodulatory effects of resveratrol suggest it may be useful in combination with other cancer therapies including immunotherapy for effective cancer management.

The PD-L1/2–PD-1 immune checkpoint is essential for the proper induction of peripheral tolerance and limits autoimmunity, whereas tumor cells exploit their expression to promote immune evasion. Many different cell types express PD-L1/2, either constitutively or upon stimulation, but the factors driving this expression are often poorly defined. In this study, using genome-wide CRISPR activation screening, we identified three factors that upregulate PD-L1 expression: GATA2, MBD6, and transcription cofactor vestigial-like protein 3 (VGLL3). VGLL3 acts as a transcriptional regulator, and its expression induced PD-L1 in many different cell types. Conversely, loss of VGLL3 impaired IFN-γ–induced PD-L1/2 expression in human keratinocytes. Mechanistically, by performing a second screen to identify proteins acting in concert with VGLL3, we found that VGLL3 forms a complex with TEAD1 and RUNX1/3 to drive expression of PD-L1/2. Collectively, our work identified a new transcriptional complex controlling PD-L1/2 expression and suggests that VGLL3, in addition to its known role in the expression of proinflammatory genes, can balance inflammation by upregulating the anti-inflammatory factors PD-L1 and PD-L2.