Beneficial effects of sunitinib on tumor microenvironment and immunotherapy targeting death receptor5

A multifunctional PEGylated liposomal-encapsulated sunitinib enhancing autophagy, immunomodulation, and safety in renal cell carcinoma

BACKGROUND

Sunitinib is a multikinase inhibitor used to treat patients with advanced renal cell carcinoma (RCC). However, sunitinib toxicity makes it a double-edged sword. Potent immune modulation by sunitinib extends to nuclear interactions. To address these issues, there is an urgent need for delivery vectors suitable for sunitinib treatment.

METHODS

We developed PEGylated liposomes as delivery vectors to precisely target sunitinib (lipo-sunitinib) to RCC tumors. Further investigations, including RNA sequencing (RNA-seq), were performed to evaluate transcriptomic changes in these pathways. DiI/DiR-labeled lipo-sunitinib was used for the biodistribution analysis. Flow cytometry and immunofluorescence (IF) were used to examine immune modulation in orthotopic RCC models.

RESULTS

The evaluation of results indicated that lipo-sunitinib precisely targeted the tumor site to induce autophagy and was readily taken up by RCC tumor cells. In addition, transcriptomic assays revealed that following lipo-sunitinib treatment, autophagy, antigen presentation, cytokine, and chemokine production pathways were upregulated, whereas the epithelial-mesenchymal transition (EMT) pathway was downregulated. In vivo data provided evidence supporting the inhibitory effect of lipo-sunitinib on RCC tumor progression and metastasis. Flow cytometry further demonstrated that liposunitinib increased the infiltration of effector T cells (Teffs) and conventional type 1 dendritic cells (cDC1s) into the tumor. Furthermore, systemic immune organs such as the tumor-draining lymph nodes, spleen, and bone marrow exhibited upregulated anticancer immunity following lipo-sunitinib treatment.

CONCLUSION

Our findings demonstrated that lipo-sunitinib is distributed at the RCC tumor site, concurrently inducing potent autophagy, elevating antigen presentation, activating cytokine and chemokine production pathways, and downregulating EMT in RCC cells. This comprehensive approach significantly enhanced tumor inhibition and promoted anticancer immune modulation.

Pericytes: jack-of-all-trades in cancer-related inflammation

Pericytes, recognized as mural cells, have long been described as components involved in blood vessel formation, playing a mere supporting role for endothelial cells (ECs). Emerging evidence strongly suggests their multifaceted roles in tissues and organs. Indeed, pericytes exhibit a remarkable ability to anticipate endothelial cell behavior and adapt their functions based on the specific cells they interact with. Pericytes can be activated by pro-inflammatory stimuli and crosstalk with immune cells, actively participating in their transmigration into blood vessels. Moreover, they can influence the immune response, often sustaining an immunosuppressive phenotype in most of the cancer types studied. In this review, we concentrate on the intricate crosstalk between pericytes and immune cells in cancer, highlighting the primary evidence regarding pericyte involvement in primary tumor mass dynamics, their contributions to tumor reprogramming for invasion and migration of malignant cells, and their role in the formation of pre-metastatic niches. Finally, we explored recent and emerging pharmacological approaches aimed at vascular normalization, including novel strategies to enhance the efficacy of immunotherapy through combined use with anti-angiogenic drugs.

The Role of Oxidative Stress in Tumorigenesis and Progression

Oxidative stress refers to the imbalance between the production of reactive oxygen species (ROS) and the endogenous antioxidant defense system. Its involvement in cell senescence, apoptosis, and series diseases has been demonstrated. Advances in carcinogenic research have revealed oxidative stress as a pivotal pathophysiological pathway in tumorigenesis and to be involved in lung cancer, glioma, hepatocellular carcinoma, leukemia, and so on. This review combs the effects of oxidative stress on tumorigenesis on each phase and cell fate determination, and three features are discussed. Oxidative stress takes part in the processes ranging from tumorigenesis to tumor death via series pathways and processes like mitochondrial stress, endoplasmic reticulum stress, and ferroptosis. It can affect cell fate by engaging in the complex relationships between senescence, death, and cancer. The influence of oxidative stress on tumorigenesis and progression is a multi-stage interlaced process that includes two aspects of promotion and inhibition, with mitochondria as the core of regulation. A deeper and more comprehensive understanding of the effects of oxidative stress on tumorigenesis is conducive to exploring more tumor therapies.

Reprogramming the pancreatic cancer stroma and immune landscape by a silicasome nanocarrier delivering nintedanib, a protein tyrosine kinase inhibitor

The prevailing desmoplastic stroma and immunosuppressive microenvironment within pancreatic ductal adenocarcinoma (PDAC) pose substantial challenges to therapeutic intervention. Despite the potential of protein tyrosine kinase (PTK) inhibitors in mitigating the desmoplastic stromal response and enhancing the immune milieu, their efficacy is curtailed by suboptimal pharmacokinetics (PK) and insufficient tumor penetration. To surmount these hurdles, we have pioneered a novel strategy, employing lipid bilayer-coated mesoporous silica nanoparticles (termed "silicasomes") as a carrier for the delivery of Nintedanib. Nintedanib, a triple PTK inhibitor that targets vascular endothelial growth factor, platelet-derived growth factor and fibroblast growth factor receptors, was encapsulated in the pores of silicasomes via a remote loading mechanism for weak bases. This innovative approach not only enhanced pharmacokinetics and intratumor drug concentrations but also orchestrated a transformative shift in the desmoplastic and immune landscape in a robust orthotopic KRAS-mediated pancreatic carcinoma (KPC) model. Our results demonstrate attenuation of vascular density and collagen content through encapsulated Nintedanib treatment, concomitant with significant augmentation of the CD8+/FoxP3+ T-cell ratio. This remodeling was notably correlated with tumor regression in the KPC model. Strikingly, the synergy between encapsulated Nintedanib and anti-PD-1 immunotherapy further potentiated the antitumor effect. Both free and encapsulated Nintedanib induced a transcriptional upregulation of PD-L1 via the extracellular signal-regulated kinase (ERK) pathway. In summary, our pioneering approach involving the silicasome carrier not only improved antitumor angiogenesis but also profoundly reshaped the desmoplastic stromal and immune landscape within PDAC. These insights hold excellent promise for the development of innovative combinatorial strategies in PDAC therapy.

Inhibiting anti-angiogenic VEGF165b activates a miR-17-20a-Calcipressin-3 pathway that revascularizes ischemic muscle in peripheral artery disease

BACKGROUND

VEGF165a increases the expression of the microRNA-17-92 cluster, promoting developmental, retinal, and tumor angiogenesis. We have previously shown that VEGF165b, an alternatively spliced anti-angiogenic VEGF-A isoform, inhibits the VEGFR-STAT3 pathway in ischemic endothelial cells (ECs) to decrease their angiogenic capacity. In ischemic macrophages (Møs), VEGF165b inhibits VEGFR1 to induce S100A8/A9 expression, which drives M1-like polarization. Our current study aims to determine whether VEGF165b inhibition promotes perfusion recovery by regulating the microRNA(miR)-17-92 cluster in preclinical PAD.

METHODS

Femoral artery ligation and resection was used as a preclinical PAD model. Hypoxia serum starvation (HSS) was used as an in vitro PAD model. VEGF165b was inhibited/neutralized by an isoform-specific VEGF165b antibody.

RESULTS

Here, we show that VEGF165b-inhibition induces the expression of miR-17-20a (within miR-17-92 (miR-17-18a-19a-19b-20a-92) cluster) in HSS-ECs and HSS-Møs vs. respective normal and/or isotype-matched IgG controls to enhance perfusion recovery. Consistent with the bioinformatics analysis that revealed RCAN3 as a common target of miR-17 and miR-20a, Argonaute-2 pull-down assays showed decreased miR-17-20a expression and higher RCAN3 expression in the RNA-induced silencing complex of HSS-ECs and HSS-Møs vs. respective controls. Inhibiting miR-17-20a induced RCAN3 levels to decrease ischemic angiogenesis and promoted M1-like polarization to impair perfusion recovery. Finally, using STAT3 inhibitors, S100A8/A9 silencers, and VEGFR1-deficient ECs and Møs, we show that VEGF165b-inhibition activates the miR-17-20a-RCAN3 pathway independent of VEGFR1-STAT3 or VEGFR1-S100A8/A9 in ischemic-ECs and ischemic-Møs respectively.

CONCLUSIONS

Our data revealed a hereunto unrecognized therapeutic 'miR-17-20a-RCAN3' pathway in the ischemic vasculature that is VEGFR1-STAT3/S100A8/A9 independent and is activated only upon VEGF165b-inhibition in PAD.

Normalizing Tumor Blood Vessels to Improve Chemotherapy and Inhibit Breast Cancer Metastasis by Multifunctional Nanoparticles

The abnormal tumor blood vessels with high leakage can promote tumor cells to infiltrate into the systemic circulation and increase the risk of tumor metastasis. In addition, chemotherapy may destroy tumor blood vessels and further aggravate metastasis. Normalizing tumor blood vessels can reduce vascular leakage and increase vascular integrity. The simultaneous administration of vascular normalization drugs and chemotherapy drugs may resist the blood vessels' destruction of chemotherapy. Here, multifunctional nanoparticles (CCM@LMSN/DOX&St), which combined chemotherapy with tumor blood vessel normalization, were prepared for the treatment of breast cancer. The results showed that CCM@LMSN/DOX&St-loaded sunitinib (St) promoted the expression of junction proteins Claudin-4 and VE-cadherin of endothelial cells, reversed the destruction of DOX to the endothelial cell layer, protected the integrity of the endothelial cell layer, and inhibited the migration of 4T1 tumor cells across the endothelial cell layer. In vivo experiments showed that CCM@LMSN/DOX&St effectively inhibited tumor growth in situ; what is exciting was that it also inhibited distal metastasis of breast cancer. CCM@LMSN/DOX&St encapsulated with St can normalize tumor blood vessels, reverse the damage of DOX to tumor blood vessels, increase the integrity of blood vessels, and prevent tumor cell invasion into blood vessels, which can inhibit breast cancer spontaneous metastasis and reduce chemotherapy-induced metastasis. This drug delivery platform effectively inhibited the progression of tumors and provided a promising solution for effective tumor treatment.

The application and research progress of anti-angiogenesis therapy in tumor immunotherapy

Tumor immunotherapy, as the focus of scientific research and clinical tumor treatment in recent years, has received extensive attention. Due to its remarkable curative effect and fewer side effects than traditional treatments, it has significant clinical benefits for the treatment of various advanced cancers and can improve cancer patient survival in the long term. Currently, most patients cannot benefit from immunotherapy, and some patients may experience tumor recurrence and drug resistance even if they achieve remission overcome. Numerous studies have shown that the abnormal angiogenesis state of tumors can lead to immunosuppressive tumor microenvironment, which affects the efficacy of immunotherapy. Actually, to improve the efficacy of immunotherapy, the application of anti-angiogenesis drugs to normalize abnormal tumor vessel has been widely confirmed in basic and clinical research. This review not only discusses the risk factors, mechanisms, and effects of abnormal and normalized tumor angiogenesis state on the immune environment, but summarizes the latest progress of immunotherapy combined with anti-angiogenic therapy. We hope this review provides an applied reference for anti-angiogenesis drugs and synergistic immunotherapy therapy.

Anatomy and function of the lymphatic vessels in the parietal pleura and their plasticity under inflammation in mice

Inflammatory pleuritis often causes pleural effusions, which are drained through lymphatic vessels (lymphatics) in the parietal pleura. The distribution of button- and zipper-like endothelial junctions can identify the subtypes of lymphatics, the initial, pre-collecting, and collecting lymphatics. Vascular endothelial growth factor receptor (VEGFR)-3 and its ligands VEGF-C/D are crucial lymphangiogenic factors. Currently, in the pleura covering the chest walls, the anatomy of the lymphatics and connecting networks of blood vessels are incompletely understood. Moreover, their pathological and functional plasticity under inflammation and the effects of VEGFR inhibition are unclear. This study aimed to learn the above-unanswered questions and immunostained mouse chest walls as whole-mount specimens. Confocal microscopic images and their 3-dimensional reconstruction analyzed the vasculatures. Repeated intra-pleural cavity lipopolysaccharide challenge induced pleuritis, which was also treated with VEGFR inhibition. Levels of vascular-related factors were evaluated by quantitative real-time polymerase chain reaction. We observed the initial lymphatics in the intercostals, collecting lymphatics under the ribs, and pre-collecting lymphatics connecting both. Arteries branched into capillaries and gathered into veins from the cranial to the caudal side. Lymphatics and blood vessels were in different layers with an adjacent distribution of the lymphatic layer to the pleural cavity. Inflammatory pleuritis elevated expression levels of VEGF-C/D and angiopoietin-2, induced lymphangiogenesis and blood vessel remodeling, and disorganized the lymphatic structures and subtypes. The disorganized lymphatics showed large sheet-like structures with many branches and holes inside. Such lymphatics were abundant in zipper-like endothelial junctions with some button-like junctions. The blood vessels were tortuous and had various diameters and complex networks. Stratified layers of lymphatics and blood vessels were disorganized, with impaired drainage function. VEGFR inhibition partially maintained their structures and drainage function. These findings demonstrate anatomy and pathological changes of the vasculatures in the parietal pleura and their potential as a novel therapeutic target.

Association between Low Forced Vital Capacity and High Pneumonia Mortality, and Impact of Muscle Power

Impaired % predicted value forced vital capacity (% FVC) is related to higher all-cause mortality in aged adults, and strong muscle force may improve this relationship. A muscle disease, sarcopenia, causes higher mortality. We aimed to identify the unknown disease that relates impaired % FVC with higher mortality in aged adults among the three major leading causes of death, and the effect of strong leg force on this relationship. Cox proportional hazard model analyzed the longitudinal Tsurugaya cohort that registered 1048 aged Japanese for 11 years. The primary outcome was the relationship between % FVC and mortality by cancer, cardiovascular disease, or pneumonia. Exposure variables were % FVC or leg force divided by 80% or median values, respectively. The secondary outcome was the effects of leg force on the relationship. Among the diseases, % FVC < 80% was related only to higher pneumonia mortality (hazard ratio [HR], 4.09; 95% CI, 1.90-8.83) relative to the % FVC ≥ 80% group before adjustment. Adding the leg force as an explanatory variable reduced the HR to 3.34 (1.54-7.25). Weak leg force might indicate sarcopenia, and its prevention may improve higher pneumonia mortality risk related to impaired % FVC, which we may advise people in clinical settings.

Anatomy and pathology of lymphatic vessels under physiological and inflammatory conditions in the mouse diaphragm

The lymphatic vessels in the parietal pleura drain fluids. Impaired drainage function and excessive fluid entry in the pleural cavity accumulate effusion. The rat diaphragmatic lymphatics drain fluids from the pleura to the muscle layer. Lymphatic subtypes are characterized by the major distribution of discontinuous button-like endothelial junctions (buttons) in initial lymphatics and continuous zipper-like junctions (zippers) in the collecting lymphatics. Inflammation replaced buttons with zippers in tracheal lymphatics. In the mouse diaphragm, the structural relationship between the lymphatics and blood vessels, the presence of lymphatics in the muscle layer, and the distributions of initial and collecting lymphatics are unclear. Moreover, the endothelial junctional alterations and effects of vascular endothelial growth factor receptor (VEGFR) inhibition under pleural inflammation are unclear. We subjected the whole-mount mouse diaphragms to immunohistochemistry. The lymphatics and blood vessels were distributed in different layers of the pleural membrane. Major lymphatic subtypes were initial lymphatics in the pleura and collecting lymphatics in the muscle layer. Chronic pleural inflammation disorganized the stratified layers of the lymphatics and blood vessels and replaced buttons with zippers in the pleural lymphatics, which impaired drainage function. VEGFR inhibition under inflammation maintained the vascular structures and drainage function. In addition, VEGFR inhibition maintained the lymphatic endothelial junctions and reduced the blood vessel permeability under inflammation. These findings may provide new targets for managing pleural effusions caused by inflammation, such as pleuritis and empyema, which are common pneumonia comorbidities.

Targeting depletion of myeloid-derived suppressor cells potentiates PD-L1 blockade efficacy in gastric and colon cancers

Myeloid-derived suppressor cells (MDSCs) have been demonstrated to suppress antitumor immunity and induce resistance to PD-1/PD-L1 blockade immunotherapy in gastric and colon cancer patients. Herein, we found that MDSCs accumulate in mice bearing syngeneic gastric cancer and colon cancer. Death receptor 5 (DR5), a receptor of TNF-related apoptosis-inducing ligand (TRAIL), was highly expressed on MDSCs and cancer cells; targeting DR5 using agonistic anti-DR5 antibody (MD5-1) specifically depleted MDSCs and induced enrichment of CD8⁺ T lymphocytes in tumors and exhibited stronger tumor inhibition efficacy in immune-competent mice than in T-cell-deficient nude mice. Importantly, the combination of MD5-1 and anti-PD-L1 antibody showed synergistic antitumor effects in gastric and colon tumor-bearing mice, resulting in significantly suppressed tumor growth and extended mice survival, whereas single-agent treatment had limited effect. Moreover, the combination therapy induced sustained memory immunity in mice that exhibited complete tumor regression. The enhanced antitumor effect was associated with increased intratumoral CD8⁺ T-cell infiltration and activation, and a more vigorous tumor-inhibiting microenvironment. In summary, our findings highlight the therapeutic potential of combining PD-L1 blockade therapy with agonistic anti-DR5 antibody that targets MDSCs in gastric and colon cancers.

Lower limb lymphedema and cellulitis as a complication of COVID-19 vaccine: A case report

A 68-year-old man without complications following his first dose of Sinopharm (BBIBP-CorV) COVID-19 vaccine developed left foot and ankle edema, extending to his left leg 3 days after his second dose. Color-Doppler sonography and lymphoscintigraphy showed extensive soft tissue swelling and fat edema in both legs, proposing lymphatic drainage disorder.

Inducing vascular normalization: A promising strategy for immunotherapy

In solid tumors, the vasculature is highly abnormal in structure and function, resulting in the formation of an immunosuppressive tumor microenvironment by limiting immune cells infiltration into tumors. Vascular normalization is receiving much attention as an alternative strategy to anti-angiogenic therapy, and its potential therapeutic targets include signaling pathways, angiogenesis-related genes, and metabolic pathways. Endothelial cells play an important role in the formation of blood vessel structure and function, and their metabolic processes drive blood vessel sprouting in parallel with the control of genetic signals in cancer. The feedback loop between vascular normalization and immunotherapy has been discussed extensively in many reviews. In this review, we summarize the impact of aberrant tumor vascular structure and function on drug delivery, metastasis, and anti-tumor immune responses. In addition, we present evidences for the mutual regulation of immune vasculature. Based on the importance of endothelial metabolism in controlling angiogenesis, we elucidate the crosstalk between endothelial cells and immune cells from the perspective of metabolic pathways and propose that targeting abnormal endothelial metabolism to achieve vascular normalization can be an alternative strategy for cancer treatment, which provides a new theoretical basis for future research on the combination of vascular normalization and immunotherapy.

Combination of tumor vessel normalization and immune checkpoint blockade for breast cancer treatment via multifunctional nanocomplexes

Tumor vessel normalization can alleviate hypoxia, reduce the intratumoral infiltration of immunosuppressive cells and increase the intratumoral infiltration of immune effector cells (CD8⁺ T cells), further reversing the immunosuppressive microenvironment. Here, nanocomplexes (lipo/St@FA-COSA/BMS-202) which can accurately deliver drugs to tumor tissues and release different drugs at different sites with different rates were prepared to combine tumor vessel normalization with immune checkpoint blockade. The results of drug release in vitro showed that in a pH 6.5 release medium, lipo/St@FA-COSA/BMS-202 rapidly released the vascular normalizing drug (sunitinib, St) and slowly released the PD-1/PD-L1-blocking drug (BMS-202). The results of in vivo experiments showed that the rapidly released St normalized tumor vessels and formed an immunosupportive microenvironment which improved the anti-tumor efficacy of BMS-202. In conclusion, the drug delivery strategy significantly inhibited tumor growth and had excellent anti-tumor efficacy, which can provide a potential approach for effective tumor treatment.

Frequent Onsets of Cellulitis in Lower Limbs with Lymphedema Following COVID-19 mRNA Vaccination

Four patients with secondary lower limb lymphedema developed cellulitis at their lymphedema lesion following COVID-19 mRNA vaccinations. They did not develop adverse effects at their vaccination site. All the patients were Japanese females aged <60 years. Three patients developed cellulitis following the first vaccination. The date of onset of cellulitis following the first vaccination varied from 0 to 21 days. Two received BNT162b2 mRNA vaccines and the others received mRNA-1273 vaccines. All the patients were treated with oral antibiotics and recovered. Two patients had repeated cellulitis. The patients with the repeated development of cellulitis could not perform good skincare. One patient had joint contractures in their lower limbs and could not reach her lymphedema lesions, and the other patient could not master the skincare. According to previous studies, the development of cellulitis following vaccination was rare. In this study, four patients aged <60 years developed cellulitis among the eight patients that regularly visited our hospital for rehabilitation for their lower limb lymphedema. In patients with lymphedema, prolonged inflammation may impair lymphatic functions and worsen edema. Therefore, at the time of vaccination, we should keep in mind the prevention and immediate management of cellulitis using intensive skincare and antibiotic treatment.

Key sunitinib-related biomarkers for renal cell carcinoma

Background

Renal cell carcinoma (RCC) contributed to 403,262 new cases worldwide in 2018, which constitutes 2.2% of global cancer, nevertheless, sunitinib, one of the major targeted therapeutic agent for RCC, often developed invalid due to resistance. Emerging evidences suggested sunitinib can impact tumor environment which has been proven to be a vital factor for tumor progression.

Methods

In the present study, we used ssGSEA to extract the immune infiltrating abundance of clear cell RCC (ccRCC) and normal control samples from GSE65615, TCGA, and GTEx; key immune cells were determined by Student's t‐test and univariable Cox analysis. Co‐expression network combined with differentially expressed analysis was then applied to derive key immune‐related genes for ccRCC, followed by the identification of hub genes using differential expression analysis. Subsequently, explorations and validations of the biological function and the immune‐related and sunitinib‐related characteristics were conducted in KEGG, TISIDB, Oncomine, ICGC, and GEO databases.

Results

We refined immature dendritic cells and central memory CD4 T cells which showed associations with sunitinib and ccRCC. Following, five hub genes (CRYBB1, RIMBP3C, CEACAM4, HAMP, and LYL1) were identified for their strong relationships with sunitinib and immune infiltration in ccRCC. Further validations in external data refined CRYBB1, CEACAM4, and HAMP which play a vital role in sunitinib resistance, immune infiltrations in ccRCC, and the development and progression of ccRCC. In conclusion, our findings could shed light on the resistance of sunitinib in ccRCC and provide novel biomarkers or drug targets for ccRCC.

To be or not to be: whether anti-angiogenic agent combined with immune checkpoint inhibitoris necessary in the treatment of advanced or metastatic renal cell carcinoma

Although it's widely known that targeted therapy against angiogenesis and immunotherapy agents showed survival benefit over chemoradiotherapy in advanced or metastatic renal cell carcinoma, some patients still cannot receive a satisfied prognosis. We performed a systematic review and meta-analysis to explore the efficacy and safety of anti-angiogenic agents combined with immune checkpoint inhibitors. We conducted a search for randomized controlled trials in Pubmed, Embase, Cochrane, and major conference. Enrolled eligible studies and extracted data were completed by two investigators to compare OS, PFS, and ORR both in PD-L1 and ITT subset. Then, we calculated the pooled RR and 95% CI of all-grade and high-grade adverse effects to study its safety. Besides, we assessed the heterogeneity through subgroup and sensitivity analysis. A total of three RCTs covering 2662 patients were enrolled. In PFS analysis, the estimated HR for ITT subset was 0.74 with 95% CI of 0.65 to 0.84 and for PD-L1 subset was 0.65 with 95% CI of 0.56 to 0.76. And in OS analysis, the result was 0.74 with 95% CI of 0.53 to 1.03 in ITT subset and 0.74 with 95% CI of 0.56 to 0.96 in PD-L1 subset. As for ORR analysis, combination therapy showed advantage rather than monotherapy in ITT subset (RR 1.54; 95% CI 1.11 to 2.14), but conversely in PD-L1 positive subset (RR 1.64; 95% CI 0.94 to 2.84). Additionally, combination therapy failed to show obvious safety in most immune-related adverse events, whatever in all-grade or high grade.

The Paradox of Cancer Immune Exclusion: Immune Oncology Next Frontier

Checkpoint inhibitor therapy (CIT) has revolutionized cancer treatment but it has also reached a standstill when an absent dialog between cancer and immune cells makes it irrelevant. This occurs with high prevalence in the context of "immune silent" and, even perhaps, "immune-excluded" tumors. The latter are characterized by T cells restricted to the periphery of cancer nests. Since in either case T cells do not come in direct contact with most cancer cells, CIT rests immaterial. Adoptive cell therapy (ACT), may also be affected by limited access to antigen-bearing cancer cells. While lack of immunogenicity intuitively explains the immune silent phenotype, immune exclusion is perplexing. The presence of T cells at the periphery suggests that chemo-attraction recruits them and an immunogenic stimulus promotes their persistence. However, what stops the T cells from infiltrating the tumors' nests and reaching the germinal center (GC)? Possibly, a concentric gradient of increased chemo-repulsion or decreased chemo-attraction demarcates an abrupt "do not trespass" warning. Various hypotheses suggest physical or functional barriers but no definitive consensus exists over the weight that each plays in human cancers. On one hand, it could be hypothesized that the intrinsic biology of cancer cells may degenerate from a "cancer stem cell" (CSC)-like phenotype in the GC toward a progressively more immunogenic phenotype prone to immunogenic cell death (ICD) at the periphery. On the other hand, the intrinsic biology of the cancer cells may not change but it is the disorderly architecture of the tumor microenvironment (TME) that alters in a centripetal direction cancer cell metabolism, both directly and indirectly, the function of surrounding stromal cells. In this chapter, we examine whether the paradoxical exclusion of T cells from tumors may serve as a model to understand the requirements for tumor immune infiltration and, correspondingly, we put forth strategies to restore the dialog between immune cells and cancer to enhance the effectiveness of immune oncology (IO) approaches.