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Tumour cell phagocytosis by antigen presenting cells (APCs) is critical to the generation of antitumour immunity. However, cancer cells can evade phagocytosis by upregulating anti-phagocytosis molecule CD47. Here, we show that CD47 blockade alone is inefficient in stimulating glioma cell phagocytosis. However, combining CD47 blockade with temozolomide results in a significant pro-phagocytosis effect due to the latter’s ability to induce endoplasmic reticulum stress response. Increased tumour cell phagocytosis subsequently enhances antigen cross-presentation and activation of cyclic GMP-AMP synthase–stimulator of interferon genes (cGAS–STING) in APCs, resulting in more efficient T cell priming. This bridging of innate and adaptive responses inhibits glioma growth, but also activates immune checkpoint. Sequential administration of an anti-PD1 antibody overcomes this potential adaptive resistance. Together, these findings reveal a dynamic relationship between innate and adaptive immune regulation in tumours and support further investigation of phagocytosis modulation as a strategy to enhance cancer immunotherapy responses. Professional antigen presenting cells (APCs) are deterred from phagocytosing cancer cells that express CD47. Here, the authors show that in glioblastoma mouse models, temozolomide improves the phagocytosis effect of CD47 blockade in APCs and results in the activation of adaptive anti-tumour responses.

Nanomedicine is a burgeoning industry but an understanding of the interaction of nanomaterials with the immune system is critical for clinical translation. Macrophages play a fundamental role in the immune system by engulfing foreign particulates such as nanoparticles. When activated, macrophages form distinct phenotypic populations with unique immune functions, however the mechanism by which these polarized macrophages react to nanoparticles is unclear. Furthermore, strategies to selectively evade activated macrophage subpopulations are lacking. Here we demonstrate that stimulated macrophages possess higher phagocytic activities and that classically activated (M1) macrophages exhibit greater phagocytic capacity than alternatively activated (M2) macrophages. We show that modification of nanoparticles with polyethylene-glycol results in decreased clearance by all macrophage phenotypes, but importantly, coating nanoparticles with CD47 preferentially lowers phagocytic activity by the M1 phenotype. These results suggest that bio-inspired nanoparticle surface design may enable evasion of specific components of the immune system and provide a rational approach for developing immune tolerant nanomedicines.

A major challenge in the development of cancer nanomedicine is the inability for nanomaterials to efficiently penetrate and deliver therapeutic agents into solid tumors. Previous studies have shown that tumor vasculature and extracellular matrix regulate the transvascular and interstitial transport of nanoparticles, both critical for successfully delivering nanomedicine into solid tumors. Within the malignant tumor microenvironment, blood vessels are morphologically abnormal and functionally exhibit substantial permeability. Furthermore, the tumor extracellular matrix (ECM), unlike that of the normal tissue parenchyma, is densely packed with collagen. These pathophysiological properties greatly impede intratumoral delivery of nanomaterials. By using an antivascular endothelial growth factor receptor antibody, DC101, and an antitransforming growth factor β1 (TGF‐β1) antibody, normalization of the tumor vasculature and ECM is achieved, respectively, in a syngeneic murine glioma model. This normalization effect results in a more organized vascular network, improves tissue perfusion, and reduces collagen density, all of which contribute to enhanced nanoparticle delivery and distribution within tumors. These findings suggest that combined vascular and ECM normalization strategies can be used to remodel the tumor microenvironment and improve nanomedicine delivery into solid tumors, which has significant implications for developing more effective combinational therapeutic strategies using cancer nanomedicine. Simultaneous normalization of tumor vasculature and extracellular matrix using antivascular endothelial growth factor receptor and antitransforming growth factor antibodies enable more efficient delivery of nanoparticles into solid tumors. The tumor microenvironment normalization strategy is expected to provide new strategies to improve the therapeutic efficacy of cancer nanomedicines.

The challenge of disease relapsed/refractory (R/R) remains a therapeutic hurdle in chimeric antigen receptor (CAR) T‐cell therapy, especially for hematological diseases, with chronic lymphocytic leukemia (CLL) being particularly resistant to CD19 CAR T cells. Currently, there is no approved CAR T‐cell therapy for CLL patients. In this study, we aimed to address this unmet medical need by choosing the B‐cell activating factor receptor (BAFF‐R) as a promising target for CAR design against CLL. BAFF‐R is essential for B‐cell survival and is consistently expressed on CLL tumors. Our research discovered that BAFF‐R CAR T‐cell therapy exerted the cytotoxic effects on both CLL cell lines and primary B cells derived from CLL patients. In addition, the CAR T cells exhibited cytotoxicity against CD19‐knockout CLL cells that are resistant to CD19 CAR T therapy. Furthermore, we were able to generate BAFF‐R CAR T cells from small blood samples collected from CLL patients and then demonstrated the cytotoxic effects of these patient‐derived CAR T cells against autologous tumor cells. Given these promising results, BAFF‐R CAR T‐cell therapy has the potential to meet the long‐standing need for an effective treatment on CLL patients. BAFF‐R CAR T cells were created (A) using a lentiviral system and tested against various malignant B‐cell lines, including CLL cells. CLL patient‐derived BAFF‐R CAR T cells were also generated to test their cytotoxicity on autologous primary malignant B cells (B). The cytotoxicity of CAR T cells was measured using degranulation, interferon‐γ release, and green fluorescent protein‐labeled killing assays (C).

Abstract INTRODUCTION: A major challenge in cancer nanotechnology is the efficient delivery of nanomedicines into solid tumors. Nanomedicine relies on a functional vascular network and minimal tissue resistance to achieve homogeneous transport and distribution in solid tumor via convection- and diffusion-based mechanisms. This is especially true for brain tumors, where the presence of specialized blood-brain barrier further impedes transport of nanomedicine from the systemic circulation into the central nervous system. Unlike blood vessels within healthy tissues, tumor vessels are often morphologically pathological and functionally impaired, due to an imbalance of pro- and antiangiogenic growth factor production within the tumor microenvironment. Furthermore, within the tumor stroma, excessive and heterogeneous productions of collagen and other matrix proteins further restrict nanomedicine distribution. METHODS: We characterized in real-time, perfusion and diffusion parameters of luminescent nanoparticles using syngeneic GL261 and the spontaneous RCAS-hPDGFb-HA/nestin Tv-a; Ink4a/Arf−/− brain tumor model with multiphoton imaging in vivo. RESULTS: We demonstrate that tumor vasculature exhibits increased permeability and decreased perfusion capacity compared with normal vessels. As a result, transport of nanomedicine across the vessel wall into the tumor stroma is strongly dependent on particle size and surface polarity. Intratumoral mapping of nanomedicine distribution reveals that once gaining entry into tumors, nanoparticles often experience perivascular clumping and are unable to reach tumor tissue beyond 20 µm from the nearest vessels. Finally, with therapeutic modulation of the tumor microenvironment using anti-VEGFr or anti-TGFβ1 antibody treatments to remodel the tumor vasculature and collagen matrix, respectively, we show that tumors begin to exhibit improved tissue perfusion with improved delivery and distribution with nanomedicine into the tumor interstitium. CONCLUSION: The successful implementation of this combined therapeutic approach can have significant implications in developing effective targeted nanomedicines for brain tumors. These findings suggest that optimized delivery of nanomedicine for brain tumors may be possible through the modulation of both the tumor vasculature and extracellular matrix.

Scientific Reports 6: Article number: 26269; published online: 19 May 2016; updated: 01 August 2016 In this Article, Wen Jiang is incorrectly affiliated with: Department of Hematology/Oncology, Mayo Clinic College of Medicine, 4500 San Pablo Road, Jacksonville FL, 32224, USA. The correct affiliationis listed below:

Abstract Tuberculosis (TB) remains a major infectious disease worldwide despite chemotherapy and BCG vaccine. The efficacy of the current TB vaccine BCG varies from 0 to 80%. New vaccines that have better protection than BCG or have the capability to boost BCG-primed immunity are urgently needed. We have previously constructed a fusion protein Ag85B-MPT64190–198 -Mtb8.4 (AMM). In this study, we investigated the immunogenicity of the fusion protein AMM in a novel adjuvant of dimethyl-dioctyldecyl ammonium bromide and BCG polysaccharide nucleic acid (DDA–BCG PSN), and its capacity to boost BCG-primed immunity. The anti-Ag85B antibodies IgG1 and IgG2a were determined using ELISA and the number of spleen cells secreting IFN-γ was determined by ELISPOT. In addition, the ability of the subunit vaccine AMM to boost BCG-primed immunity against Mycobacterium tuberculosis was analyzed. The fusion protein AMM induced more effective humoral and cell-mediated immune responses in mice than Ag85B alone. Mice primed with BCG vaccination followed by boosting with AMM produced a stronger immune response and afforded a better protection against M. tuberculosis infection than mice immunized with BCG alone or BCG priming followed by boosting with Ag85B. These findings suggest that AMM is a promising candidate subunit vaccine to enhance the protective efficiency of BCG.

Two major obstacles facing cancer nanomedicine are the tendency of nanoparticles to be taken up by normal tissues and organs and the nanoparticles' inability to efficiently penetrate solid tumours. Although substantial efforts have been made to improve the intratumoural delivery of nanotherapeutics, many strategies have failed to produce meaningful clinical benefits. Recent advances in the field of immuno-oncology have led to drugs that boost the host's own immune system to fight cancer. In contrast to conventional therapies, which often target cancer cells, immunotherapies stimulate immune cells in ways that promote their recognition and the eradication of tumours. In this Perspective, we posit that this approach represents a new framework for cancer nanomedicine, and that immune-targeted nanomedicines could generate tumouricidal effects without the need to overcome the pathophysiological barriers that are intrinsic to the tumour microenvironment and that hinder nanoparticle delivery. The rational design of new immuno-oncology nanomedicines provides opportunities for developing the next generation of nanotherapeutics for cancer patients. Drawing from recent successes in cancer immunotherapy, this Perspective discusses that effective cancer-nanomedicine therapies can be designed to prime antitumour immunity far from the site of disease.

Solid tumours display a limited response to immunotherapies. By contrast, haematological malignancies exhibit significantly higher response rates to immunotherapies as compared with solid tumours. Among several microenvironmental and biological disparities, the differential expression of unique immune regulatory molecules contributes significantly to the interaction of blood cancer cells with immune cells. The self-ligand receptor of the signalling lymphocytic activation molecule family member 7 (SLAMF7), a molecule that is critical in promoting the body’s innate immune cells to detect and engulf cancer cells, is expressed nearly exclusively on the cell surface of haematologic tumours, but not on solid ones. Here we show that a bispecific nanobioconjugate that enables the decoration of SLAMF7 on the surface of solid tumours induces robust phagocytosis and activates the phagocyte cyclic guanosine monophosphate–adenosine monophosphate synthase–stimulator of interferon genes (cGAS–STING) pathway, sensitizing the tumours to immune checkpoint blockade. Our findings support an immunological conversion strategy that uses nano-adjuvants to improve the effectiveness of immunotherapies for solid tumours.Solid tumours are less responsive to immunotherapies than haematological tumours due to specific biological differences. In this paper the authors propose a strategy to decorate the cell membrane of solid tumours with a protein typically present on haematological tumour cells that promotes phagocytosis of cancer cells, and show that this results in an increased immunotherapy efficacy in animal models of solid tumours.

A multivalent bi-specific nanoconjugate can promote immune cells to recognize and eradicate cancer cells in a receptor targeted manner, leading to the generation of potent and durable anti-tumour immunity. Tumour-targeted immunotherapy offers the unique advantage of specific tumouricidal effects with reduced immune-associated toxicity 1 , 2 . However, existing platforms suffer from low potency, inability to generate long-term immune memory and decreased activities against tumour-cell subpopulations with low targeting receptor levels 3 , 4 , 5 . Here we adopted a modular design approach that uses colloidal nanoparticles as substrates to create a multivalent bi-specific nanobioconjugate engager (mBiNE) to promote selective, immune-mediated eradication of cancer cells. By simultaneously targeting the human epidermal growth factor receptor 2 (HER2) expressed by cancer cells 6 and pro-phagocytosis signalling mediated by calreticulin 7 , the mBiNE stimulated HER2-targeted phagocytosis and produced durable antitumour immune responses against HER2-expressing tumours. Interestingly, although the initial immune activation mediated by the mBiNE was receptor dependent, the subsequent antitumour immunity also generated protective effects against tumour-cell populations that lacked the HER2 receptor. Thus, the mBiNE represents a new targeted, nanomaterial-immunotherapy platform to stimulate innate and adaptive immunity and promote a universal antitumour response.