Targeting autophagy inhibits melanoma growth by enhancing NK cells infiltration in a CCL5-dependent manner.

While blocking tumor growth by targeting autophagy is well established, its role on the infiltration of natural killer (NK) cells into tumors remains unknown. Here, we investigate the impact of targeting autophagy gene Beclin1 (BECN1) on the infiltration of NK cells into melanomas. We show that, in addition to inhibiting tumor growth, targeting BECN1 increased the infiltration of functional NK cells into melanoma tumors. We provide evidence that driving NK cells to the tumor bed relied on the ability of autophagy-defective tumors to transcriptionally overexpress the chemokine gene CCL5 Such infiltration and tumor regression were abrogated by silencing CCL5 in BECN1-defective tumors. Mechanistically, we show that the up-regulated expression of CCL5 occurred through the activation of its transcription factor c-Jun by a mechanism involving the impairment of phosphatase PP2A catalytic activity and the subsequent activation of JNK. Similar to BECN1, targeting other autophagy genes, such as ATG5, p62/SQSTM1, or inhibiting autophagy pharmacologically by chloroquine, also induced the expression of CCL5 in melanoma cells. Clinically, a positive correlation between CCL5 and NK cell marker NKp46 expression was found in melanoma patients, and a high expression level of CCL5 was correlated with a significant improvement of melanoma patients' survival. We believe that this study highlights the impact of targeting autophagy on the tumor infiltration by NK cells and its benefit as a novel therapeutic approach to improve NK-based immunotherapy.

Cutting Edge: NANOG Activates Autophagy under Hypoxic Stress by Binding to BNIP3L Promoter.

Hypoxia upregulates the core pluripotency factors NANOG, SOX2, and OCT4, associated with tumor aggressiveness and resistance to conventional anticancer treatments. We have previously reported that hypoxia-induced NANOG contributed in vitro to tumor cell resistance to autologous-specific CTL and in vivo to the in situ recruitment of immune-suppressive cells. In this study, we investigated the mechanisms underlying NANOG-mediated tumor cell resistance to specific lysis under hypoxia. We demonstrated the tumor-promoting effect of hypoxia on tumor initiation into immunodeficient mice using human non-small lung carcinoma cells. We next showed a link between NANOG and autophagy activation under hypoxia because inhibition of NANOG decreased autophagy in tumor cells. Chromatin immunoprecipitation and luciferase reporter assays revealed a direct binding of NANOG to a transcriptionally active site in a BNIP3L enhancer sequence. These data establish a new link between the pluripotency factor NANOG and autophagy involved in resistance to CTL under hypoxia.

The Selective Degradation of Synaptic Connexin 43 Protein by Hypoxia-induced Autophagy Impairs Natural Killer Cell-mediated Tumor Cell Killing.

Although natural killer (NK) cells play an important role in the control of melanoma, hypoxic stress in the tumor microenvironment may impair NK-mediated tumor cell killing by mechanisms that are not fully understood. In this study, we investigated the effect of hypoxia on the expression and channel activity of connexin 43 (Cx43) in melanoma cells and its impact on their susceptibility to NK cell-mediated lysis. Our results demonstrated that hypoxic stress increases Cx43 expression in melanoma cells via hypoxia-inducible factor-1α (HIF-1α) transcriptional activity. Hypoxic cells displaying increased Cx43 expression were less susceptible to NK cell-mediated lysis compared with normoxic cells expressing a moderate level of Cx43. Conversely, when overexpressed in normoxic tumor cells, Cx43 improves their susceptibility to N cell-mediated killing. We show that the NK cell immune synapse formed with normoxic melanoma cells is more stable and contains a high level of gap-junctional Cx43 whereas that formed with hypoxic cells is less stable and contains a significant lower level of gap-junctional Cx43. We provide evidence that the activation of autophagy in hypoxic melanoma cells selectively degrades gap-junctional Cx43, leading to the destabilization of the immune synapse and the impairment of NK cell-mediated killing. Inhibition of autophagy by genetic or pharmacological approaches as well as expression of the non-degradable form of Cx43 significantly restore its accumulation at the immune synapse and improves N cell-mediated lysis of hypoxic melanoma cells. This study provides the first evidence that the hypoxic microenvironment negatively affects the immune surveillance of tumors by NK cells through the modulation of Cx43-mediated intercellular communications.

Granzyme B degradation by autophagy decreases tumor cell susceptibility to natural killer-mediated lysis under hypoxia.

Recent studies demonstrated that autophagy is an important regulator of innate immune response. However, the mechanism by which autophagy regulates natural killer (NK) cell-mediated antitumor immune responses remains elusive. Here, we demonstrate that hypoxia impairs breast cancer cell susceptibility to NK-mediated lysis in vitro via the activation of autophagy. This impairment was not related to a defect in target cell recognition by NK cells but to the degradation of NK-derived granzyme B in autophagosomes of hypoxic cells. Inhibition of autophagy by targeting beclin1 (BECN1) restored granzyme B levels in hypoxic cells in vitro and induced tumor regression in vivo by facilitating NK-mediated tumor cell killing. Together, our data highlight autophagy as a mechanism underlying the resistance of hypoxic tumor cells to NK-mediated lysis. The work presented here provides a cutting-edge advance in our understanding of the mechanism by which hypoxia-induced autophagy impairs NK-mediated lysis in vitro and paves the way for the formulation of more effective NK cell-based antitumor therapies.

Hypoxia: a key player in antitumor immune response. A Review in the Theme: Cellular Responses to Hypoxia.

The tumor microenvironment is a complex system, playing an important role in tumor development and progression. Besides cellular stromal components, extracellular matrix fibers, cytokines, and other metabolic mediators are also involved. In this review we outline the potential role of hypoxia, a major feature of most solid tumors, within the tumor microenvironment and how it contributes to immune resistance and immune suppression/tolerance and can be detrimental to antitumor effector cell functions. We also outline how hypoxic stress influences immunosuppressive pathways involving macrophages, myeloid-derived suppressor cells, T regulatory cells, and immune checkpoints and how it may confer tumor resistance. Finally, we discuss how microenvironmental hypoxia poses both obstacles and opportunities for new therapeutic immune interventions.

Cutting edge: Hypoxia-induced Nanog favors the intratumoral infiltration of regulatory T cells and macrophages via direct regulation of TGF-ß1.

Emerging evidence suggests a link between tumor hypoxia and immune suppression. In this study, we investigated the role of hypoxia-induced Nanog, a stemness-associated transcription factor, in immune suppression. We observed that hypoxia-induced Nanog correlated with the acquisition of stem cell-like properties in B16-F10 cells. We further show that Nanog was selectively induced in hypoxic areas of B16-F10 tumors. Stable short hairpin RNA-mediated depletion of Nanog, combined with melanocyte differentiation Ag tyrosinase-related protein-2 peptide-based vaccination, resulted in complete inhibition of B16-F10 tumor growth. Nanog targeting significantly reduced immunosuppressive cells (regulatory T cells and macrophages) and increased CD8(+) T effector cells in tumor bed in part by modulating TGF-ß1 production. Additionally, Nanog regulated TGF-ß1 under hypoxia by directly binding the TGF-ß1 proximal promoter. Collectively, our data establish a novel functional link between hypoxia-induced Nanog and TGF-ß1 regulation and point to a major role of Nanog in hypoxia-driven immunosuppression.

[Tumor hypoxia: a key player in the regulation of stromal and anti-tumor responses]. / L'hypoxie tumorale - un déterminant clé de la réactivité stromale et de la réponse antitumorale.

Hypoxia is a major feature of most solid tumors. Cells adapt to lower oxygen availability by stabilizing HIF transcription factors, which in turn activate the expression of many genes resulting in the survival and maintenance of cellular functions. In tumor cells, exposure to hypoxic stress results in the activation, via the HIF factors, of a series of genes enabling tumor cells to resist to killing by cytotoxic effectors of the immune system. Tissue hypoxia also controls the functions and differentiation of immune cells. This review describes the hypoxia-induced mechanisms of tumor resistance to killing by cytotoxic effectors, and the functional effects of hypoxia on the immune cells.

Combining VPS34 inhibitors with STING agonists enhances type I interferon signaling and anti-tumor efficacy.

An immunosuppressive tumor microenvironment promotes tumor growth and is one of the main factors limiting the response to cancer immunotherapy. We have previously reported that inhibition of vacuolar protein sorting 34 (VPS34), a crucial lipid kinase in the autophagy/endosomal trafficking pathway, decreases tumor growth in several cancer models, increases infiltration of immune cells and sensitizes tumors to anti-programmed cell death protein 1/programmed cell death 1 ligand 1 therapy by upregulation of C-C motif chemokine 5 (CCL5) and C-X-C motif chemokine 10 (CXCL10) chemokines. The purpose of this study was to investigate the signaling mechanism leading to the VPS34-dependent chemokine increase. NanoString gene expression analysis was applied to tumors from mice treated with the VPS34 inhibitor SB02024 to identify key pathways involved in the anti-tumor response. We showed that VPS34 inhibitors increased the secretion of T-cell-recruitment chemokines in a cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes protein (STING)-dependent manner in cancer cells. Both pharmacological and small interfering RNA (siRNA)-mediated VPS34 inhibition increased cGAS/STING-mediated expression and secretion of CCL5 and CXCL10. The combination of VPS34 inhibitor and STING agonist further induced cytokine release in both human and murine cancer cells as well as monocytic or dendritic innate immune cells. Finally, the VPS34 inhibitor SB02024 sensitized B16-F10 tumor-bearing mice to STING agonist treatment and significantly improved mice survival. These results show that VPS34 inhibition augments the cGAS/STING pathway, leading to greater tumor control through immune-mediated mechanisms. We propose that pharmacological VPS34 inhibition may synergize with emerging therapies targeting the cGAS/STING pathway.

Hypoxia-dependent inhibition of tumor cell susceptibility to CTL-mediated lysis involves NANOG induction in target cells.

Hypoxia is a major feature of the solid tumor microenvironment and is known to be associated with tumor progression and poor clinical outcome. Recently, we reported that hypoxia protects human non-small cell lung tumor cells from specific lysis by stabilizing hypoxia-inducible factor-1α and inducing STAT3 phosphorylation. In this study, we show that NANOG, a transcription factor associated with stem cell self renewal, is a new mediator of hypoxia-induced resistance to specific lysis. Our data indicate that under hypoxic conditions, NANOG is induced at both transcriptional and translational levels. Knockdown of the NANOG gene in hypoxic tumor cells is able to significantly attenuate hypoxia-induced tumor resistance to CTL-dependent killing. Such knockdown correlates with an increase of target cell death and an inhibition of hypoxia-induced delay of DNA replication in these cells. Interestingly, NANOG depletion results in inhibition of STAT3 phosphorylation and nuclear translocation. To our knowledge, this study is the first to show that hypoxia-induced NANOG plays a critical role in tumor cell response to hypoxia and promotes tumor cell resistance to Ag-specific lysis.

Microenvironmental hypoxia orchestrating the cell stroma cross talk, tumor progression and antitumor response.

Hypoxia, a common feature of solid tumors and one of the hallmarks of tumor microenvironment, favors tumor survival and progression. Although hypoxia has been reported to play a major role in the acquisition of tumor resistance to cell death, the molecular mechanisms that control the survival of hypoxic cancer cells and the role of hypoxic stress in shaping the cross talk between immune cells and stroma components are not fully elucidated. Recently, several lines of investigation are pointing to yet another ominous outcome of hypoxia in the tumor microenvironment involving suppression of antitumor immune effector cells and enhancement of tumor escape from immune surveillance. Although the identification of tumor-associated antigens provided a new arsenal of approaches to enhance antigen-specific response, the immunotherapy approaches that are currently used in the clinic have only limited success. In fact, tumor stroma components including hypoxia are engaged in an active molecular cross talk that has serious implications for immunological recognition of tumor in shaping the microenvironment. In this review, we will focus on the impact of hypoxia on the regulation of the antitumor response and the subsequent tumor progression. We will also in particular discuss data that indicate that manipulation of hypoxic stress may represent an innovative strategy for a better immunotherapy of cancer.

The ß-carboline Harmine improves the therapeutic benefit of anti-PD1 in melanoma by increasing the MHC-I-dependent antigen presentation.

Harmine is a dual-specificity tyrosine-regulated kinase 1A (DYRK1A) inhibitor that displays a number of biological and pharmacological properties. Also referred to as ACB1801 molecule, we have previously reported that harmine increases the presentation of major histocompatibility complex (MHC)-I-dependent antigen on melanoma cells. Here, we show that ACB1801 upregulates the mRNA expression of several proteins of the MHC-I such as Transporter Associated with antigen Processing TAP1 and 2, Tapasin and Lmp2 (hereafter referred to as MHC-I signature) in melanoma cells. Treatment of mice bearing melanoma B16-F10 with ACB1801 inhibits the growth and weight of tumors and induces a profound modification of the tumor immune landscape. Strikingly, combining ACB1801 with anti-PD1 significantly improves its therapeutic benefit in B16-F10 melanoma-bearing mice. These results suggest that, by increasing the MHC-I, ACB1801 can be combined with anti-PD1/PD-L1 therapy to improve the survival benefit in cancer patients displaying a defect in MHC-I expression. This is further supported by data showing that i) high expression levels of TAP1, Tapasin and Lmp2 was observed in melanoma patients that respond to anti-PD1; ii) the survival is significantly improved in melanoma patients who express high MHC-I signature relative to those expressing low MHC-I signature; and iii) high expression of MHC-I signature in melanoma patients was correlated with increased expression of CD8 and NK cell markers and overexpression of proinflammatory chemokines involved in the recruitment of CD8+ T cells.

SNAI1-dependent upregulation of CD73 increases extracellular adenosine release to mediate immune suppression in TNBC.

Triple-negative subtype of breast cancer (TNBC) is hallmarked by frequent disease relapse and shows highest mortality rate. Although PD-1/PD-L1 immune checkpoint blockades have recently shown promising clinical benefits, the overall response rate remains largely insufficient. Hence, alternative therapeutic approaches are warranted. Given the immunosuppressive properties of CD73-mediated adenosine release, CD73 blocking approaches are emerging as attractive strategies in cancer immunotherapy. Understanding the precise mechanism regulating the expression of CD73 is required to develop effective anti-CD73-based therapy. Our previous observations demonstrate that the transcription factors driving epithelial-to-mesenchymal transition (EMT-TF) can regulate the expression of several inhibitory immune checkpoints. Here we analyzed the role of the EMT-TF SNAI1 in the regulation of CD73 in TNBC cells. We found that doxycycline-driven SNAI1 expression in the epithelial -like TNBC cell line MDA-MB-468 results in CD73 upregulation by direct binding to the CD73 proximal promoter. SNAI1-dependent upregulation of CD73 leads to increased production and release of extracellular adenosine by TNBC cells and contributes to the enhancement of TNBC immunosuppressive properties. Our data are validated in TNBC samples by showing a positive correlation between the mRNA expression of CD73 and SNAI1. Overall, our results reveal a new CD73 regulation mechanism in TNBC that participates in TNBC-mediated immunosuppression and paves the way for developing new treatment opportunities for CD73-positive TNBC.

Mitochondria preserve an autarkic one-carbon cycle to confer growth-independent cancer cell migration and metastasis.

Metastasis is the most common cause of death in cancer patients. Canonical drugs target mainly the proliferative capacity of cancer cells, which leaves slow-proliferating, persistent cancer cells unaffected. Metabolic determinants that contribute to growth-independent functions are still poorly understood. Here we show that antifolate treatment results in an uncoupled and autarkic mitochondrial one-carbon (1C) metabolism during cytosolic 1C metabolism impairment. Interestingly, antifolate dependent growth-arrest does not correlate with decreased migration capacity. Therefore, using methotrexate as a tool compound allows us to disentangle proliferation and migration to profile the metabolic phenotype of migrating cells. We observe that increased serine de novo synthesis (SSP) supports mitochondrial serine catabolism and inhibition of SSP using the competitive PHGDH-inhibitor BI-4916 reduces cancer cell migration. Furthermore, we show that sole inhibition of mitochondrial serine catabolism does not affect primary breast tumor growth but strongly inhibits pulmonary metastasis. We conclude that mitochondrial 1C metabolism, despite being dispensable for proliferative capacities, confers an advantage to cancer cells by supporting their motility potential.

Endothelial cells as key determinants of the tumor microenvironment: interaction with tumor cells, extracellular matrix and immune killer cells.

Besides tumor cells, the tumor microenvironment harbors a variety of host-derived cells, such as endothelial cells, fibroblasts, innate and adaptive immune cells. It is a complex and highly dynamic environment, providing very important cues to tumor development and progression. Tumor-associated endothelial cells play a key role in this process. On the one hand, they form tumor-associated (angiogenic) vessels through sprouting from locally preexisting vessels or recruitment of bone marrow-derived endothelial progenitor cells, to provide nutritional support to the growing tumor. On the other hand, they are the interface between circulating blood cells, tumor cells and the extracellular matrix, thereby playing a central role in controlling leukocyte recruitment, tumor cell behavior and metastasis formation. Hypoxia is a critical parameter modulating the tumor microenvironment and endothelial/tumor cell interactions. Under hypoxic stress, tumor cells produce factors that promote tumor angiogenesis, tumor cell motility and metastasis. Among these factors, VEGF, a main angiogenesis modulator, can also play a critical role in the control of immune tolerance. This review discusses some aspects of the role of endothelial cells within tumor microenvironment and emphasizes their interaction with tumor cells, the extracellular matrix and with immune killer cells. We will also address the role played by circulating endothelial progenitor cells and illustrate their features and mechanism of recruitment to the tumor microenvironment and their role in tumor angiogenesis.

The cooperative induction of hypoxia-inducible factor-1 alpha and STAT3 during hypoxia induced an impairment of tumor susceptibility to CTL-mediated cell lysis.

Hypoxia is an essential component of tumor microenvironment. In this study, we investigated the influence of hypoxia (1% PO(2)) on CTL-mediated tumor cell lysis. We demonstrate that exposure of target tumor cells to hypoxia has an inhibitory effect on the CTL clone (Heu171)-induced autologous target cell lysis. Such inhibition correlates with hypoxia-inducible factor-1alpha (HIF-1alpha) induction but is not associated with an alteration of CTL reactivity as revealed by granzyme B polarization or morphological change. Western blot analysis indicates that although hypoxia had no effect on p53 accumulation, it induced the phosphorylation of STAT3 in tumor cells by a mechanism at least in part involving vascular endothelial growth factor secretion. We additionally show that a simultaneous nuclear translocation of HIF-1alpha and phospho-STAT3 was observed. Interestingly, gene silencing of STAT3 by small interfering RNA resulted in HIF-1alpha inhibition and a significant restoration of target cell susceptibility to CTL-induced killing under hypoxic conditions by a mechanism involving at least in part down-regulation of AKT phosphorylation. Moreover, knockdown of HIF-1alpha resulted in the restoration of target cell lysis under hypoxic conditions. This was further supported by DNA microarray analysis where STAT3 inhibition resulted in a partly reversal of the hypoxia-induced gene expression profile. The present study demonstrates that the concomitant hypoxic induction of phospho-STAT3 and HIF-1alpha are functionally linked to the alteration of non-small cell lung carcinoma target susceptibility to CTL-mediated killing. Considering the eminent functions of STAT3 and HIF-1alpha in the tumor microenvironment, their targeting may represent novel strategies for immunotherapeutic intervention.

Targeting Cytoprotective Autophagy to Enhance Anticancer Therapies.

Autophagy is a highly regulated multi-step process that occurs at the basal level in almost all cells. Although the deregulation of the autophagy process has been described in several pathologies, the role of autophagy in cancer as a cytoprotective mechanism is currently well established and supported by experimental and clinical evidence. Our understanding of the molecular mechanism of the autophagy process has largely contributed to defining how we can harness this process to improve the benefit of cancer therapies. While the role of autophagy in tumor resistance to chemotherapy is extensively documented, emerging data point toward autophagy as a mechanism of cancer resistance to radiotherapy, targeted therapy, and immunotherapy. Therefore, manipulating autophagy has emerged as a promising strategy to overcome tumor resistance to various anti-cancer therapies, and autophagy modulators are currently evaluated in combination therapies in several clinical trials. In this review, we will summarize our current knowledge of the impact of genetically and pharmacologically modulating autophagy genes and proteins, involved in the different steps of the autophagy process, on the therapeutic benefit of various cancer therapies. We will also briefly discuss the challenges and limitations to developing potent and selective autophagy inhibitors that could be used in ongoing clinical trials.

Epithelial to Mesenchymal Transition Regulates Surface PD-L1 via CMTM6 and CMTM7 Induction in Breast Cancer.

CMTM6 is a critical regulator of cell surface expression of PD-L1 in tumor cells, but little is known about the transcriptional regulation of CMTM6. Here we report that the expression of CMTM6 positively correlates with the epithelial to mesenchymal transition (EMT) score in breast cancer cell lines and with the major EMT marker Vimentin in triple-negative breast cancers (TNBC). We showed that CMTM6 is concomitantly overexpressed with PD-L1 in breast mesenchymal compared with the epithelial cells. Driving a mesenchymal phenotype in SNAI1-inducible MCF-7 cells (MCF-7Mes cells) increased both PD-L1 and CMTM6. CMTM6 silencing in MCF-7Mes cells partially reduced cell surface expression of PD-L1, indicating that a proportion of the PD-L1 on the surface of MCF-7Mes cells depends on CMTM6. We also found a positive correlation between CMTM3 and CMTM7 expression with EMT score in breast cancer cells, and with Vimentin in TNBC patients. Dual knockdown of CMTM6 and CMTM7 significantly decreased PD-L1 surface expression in MCF-7Mes cells, indicating that both CMTM6 and CMTM7 regulate the expression of PD-L1. This study highlights the importance of CMTM6 and CMTM7 in EMT-induced PD-L1 and suggests that EMT, CMTM6 or CMTM7 modulators can be combined with anti-PD-L1 in patients with highly aggressive breast cancer.

CXCL10 Is an Agonist of the CC Family Chemokine Scavenger Receptor ACKR2/D6.

Atypical chemokine receptors (ACKRs) are important regulators of chemokine functions. Among them, the atypical chemokine receptor ACKR2 (also known as D6) has long been considered as a scavenger of inflammatory chemokines exclusively from the CC family. In this study, by using highly sensitive ß-arrestin recruitment assays based on NanoBiT and NanoBRET technologies, we identified the inflammatory CXC chemokine CXCL10 as a new strong agonist ligand for ACKR2. CXCL10 is known to play an important role in the infiltration of immune cells into the tumour bed and was previously reported to bind to CXCR3 only. We demonstrated that ACKR2 is able to internalize and reduce the availability of CXCL10 in the extracellular space. Moreover, we found that, in contrast to CC chemokines, CXCL10 activity towards ACKR2 was drastically reduced by the dipeptidyl peptidase 4 (DPP4 or CD26) N-terminal processing, pointing to a different receptor binding pocket occupancy by CC and CXC chemokines. Overall, our study sheds new light on the complexity of the chemokine network and the potential role of CXCL10 regulation by ACKR2 in many physiological and pathological processes, including tumour immunology. Our data also testify that systematic reassessment of chemokine-receptor pairing is critically needed as important interactions may remain unexplored.

Targeting HIF-1 alpha transcriptional activity drives cytotoxic immune effector cells into melanoma and improves combination immunotherapy.

Hypoxia is a key factor responsible for the failure of therapeutic response in most solid tumors and promotes the acquisition of tumor resistance to various antitumor immune effectors. Reshaping the hypoxic immune suppressive tumor microenvironment to improve cancer immunotherapy is still a relevant challenge. We investigated the impact of inhibiting HIF-1α transcriptional activity on cytotoxic immune cell infiltration into B16-F10 melanoma. We showed that tumors expressing a deleted form of HIF-1α displayed increased levels of NK and CD8+ effector T cells in the tumor microenvironment, which was associated with high levels of CCL2 and CCL5 chemokines. We showed that combining acriflavine, reported as a pharmacological agent preventing HIF-1α/HIF-1ß dimerization, dramatically improved the benefit of cancer immunotherapy based on TRP-2 peptide vaccination and anti-PD-1 blocking antibody. In melanoma patients, we revealed that tumors exhibiting high CCL5 are less hypoxic, and displayed high NK, CD3+, CD4+ and CD8+ T cell markers than those having low CCL5. In addition, melanoma patients with high CCL5 in their tumors survive better than those having low CCL5. This study provides the pre-clinical proof of concept for a novel triple combination strategy including blocking HIF-1α transcription activity along vaccination and PD-1 blocking immunotherapy.

Firing up the cold tumors by targeting Vps34.

Cancer immunotherapy based on anti-PD-1/PD-L1 blockade is particularly effective in responding to patients with hot tumors. These tumors are characterized by the accumulation of proinflammatory cytokines and T cell infiltration. In our recent report published in Science Advances, we demonstrate that targeting the autophagy-related protein Vps34 switched cold immune desert tumors into hot inflamed immune-infiltrated tumors and enhanced the efficacy of anti-PD-1/PD-L1. Our study provides the preclinical rationale to set up combination immunotherapy clinical trials using selective Vps34 inhibitors and immune checkpoint blockers in melanoma and CRC.