Biodegradable MXene Quantum Dots with High Near-Infrared Photothermal Performance for Cancer Treatment.

Photothermal therapy (PTT) offers significant potential in cancer treatment due to its short, simple, and less harmful nature. However, obtaining a photothermal agent (PTA) with good photothermal performance and biocompatibility remains a challenge. MXenes, which are PTAs, have shown promising results in cancer treatment. This study presents the preparation of Ti3C2 MXene quantum dots (MXene QDs) using a simple hydrothermal and ultrasonic method and their use as a PTA for cancer treatment. Compared to conventional MXene QDs synthesized using only the hydrothermal method, the ultrasonic process increased the degree of oxidation on the surface of the MXene QDs. This resulted in the presence of more hydrophilic groups such as hydroxyl groups on the MXene QD surfaces, leading to excellent dispersion in the aqueous system and biocompatibility of the prepared MXene QDs without the need for surface modification. The MXene QDs showed great photothermal performance with a photothermal conversion efficiency of 62.5%, resulting in the highest photothermal conversion efficiency among similar materials reported thus far. Both in vitro and in vivo experiments have proved the potent tumor inhibitory effect of the MXene QD-mediated PTT, with minimal harm to mice. Therefore, these MXene QDs hold a significant promise for clinical applications.

An attenuated lymphocytic choriomeningitis virus vector enhances tumor control in mice partly via IFN-I.

Viral vectors are being used for the treatment of cancer. Yet, their efficacy varies among tumors and their use poses challenges in immunosuppressed patients, underscoring the need for alternatives. We report striking antitumoral effects by a nonlytic viral vector based on attenuated lymphocytic choriomeningitis virus (r3LCMV). We show in multiple tumor models that injection of tumor-bearing mice with this vector results in improved tumor control and survival. Importantly, r3LCMV improved tumor control in immunodeficient Rag1-/- mice and MyD88-/- mice, suggesting that multiple pathways contributed to the antitumoral effects. The antitumoral effects of r3LCMV were also observed when this vector was administered several weeks before tumor challenges, suggesting the induction of trained immunity. Single-cell RNA sequencing analyses, antibody blockade experiments, and knockout models revealed a critical role for host-intrinsic IFN-I in the antitumoral efficacy of r3LCMV vectors. Collectively, these data demonstrate potent antitumoral effects by r3LCMV vectors and unveil multiple mechanisms underlying their antitumoral efficacy.

A novel acceptor-donor-acceptor structured molecule-based nanosystem for tumor mild photothermal therapy.

Although photothermal therapy (PTT) is effective at killing tumor cells, it can inadvertently damage healthy tissues surrounding the tumor. Nevertheless, lowering the treatment temperature will reduce the therapeutic effectiveness. In this study, we employed 2,2'-((2Z,2'Z)-((4,4,9,9-Tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene)) dimalononitrile (IDIC), a molecule possessing a conventional acceptor-donor-acceptor (A-D-A) structure, as a photothermal agent (PTA) to facilitate effective mild photothermal therapy (mPTT). IDIC promotes intramolecular charge transfer under laser irradiation, making it a promising candidate for mPTT. To enhance the therapeutic potential of IDIC, we incorporated quercetin (Qu) into IDIC to form IDIC-Qu nanoparticles (NPs), which can inhibit heat shock protein (HSP) activity during the process of mPTT. Moreover, IDIC-Qu NPs exhibited exceptional water dispersibility and passive targeting abilities towards tumor tissues, attributed to its enhanced permeation and retention (EPR) effect. These advantageous properties position IDIC-Qu NPs as a promising candidate for targeted tumor treatment. Importantly, the IDIC-Qu NPs demonstrated controllable photothermal effects, leading to outstanding in vitro cytotoxicity against cancer cells and effective in vivo tumor ablation through mPTT. IDIC-Qu NPs nano-system enriches the family of organic PTAs and holds significant promise for future clinical applications of mPTT.

Immune-check blocking combination multiple cytokines shown curative potential in mice tumor model.

OBJECTIVE: In order to ensure the stable transcription of target genes, we constructed a eukaryotic high expression vector carrying an immune-check inhibitor PD-1v and a variety of cytokines, and studied their effects on activating immune response to inhibit tumor growth. METHODS: A novel eukaryotic expression plasmid vector named pT7AMPCE containing T7RNA polymerase, T7 promoter, internal ribosome entry site (IRES), and poly A tailing signal was constructed by T4 DNA ligase, on which homologous recombination was used to clone and construct the vector carrying PD-1v, IL-2/15, IL-12, GM-CSF, and GFP. In vitro transfection of CT26 cells was performed, and the protein expression of PD-1v, IL-12 and GM-CSF was detected by Western blot and ELISA after 48 h. Mice were subcutaneously inoculated with CT26-IRFP tumor cells in the rib abdomen, and the tumor tissues were injected with PD-1v, IL-2/15, IL-12, and GM-CSF recombinant plasmids for treatment during the experimental period. The efficacy of the treatment was evaluated by assay tumor size and survival time of tumor-bearing mice during the experiment. Expression levels of IFN-γ, TNF, IL-4, IL-2, and IL-5 in mouse blood were measured using the CBA method. Tumor tissues were extracted and immune cell infiltration in tumor tissues was detected by HE staining and the IHC method. RESULTS: The recombinant plasmids carrying PD-1v, IL-2/15, IL-12, and GM-CSF were successfully constructed, and the Western blot and ELISA results showed that PD-1v, IL-12, and GM-CSF were expressed in the supernatant of CT26 cells 48 h after in vitro cell transfection. The combined application of PD-1v, IL-2/15, IL-12, and GM-CSF recombinant plasmids significantly inhibited tumor growth in mice, and the tumor growth rate was significantly lower than that in the blank control group and GFP plasmid control group (p < 0.05). Cytometric bead array data suggested that the combination of PD-1v and various cytokines can effectively activate immune cells. HE and IHC analysis revealed plenty of immune cell infiltrates in the tumor tissue, and a large proportion of tumor cells showed the necrotic phenotype in the combination treatment group. CONCLUSION: The combination of immune check blockade and multiple cytokine therapy can significantly activate the body's immune response and inhibit tumor growth.

Orthogonal cytokine engineering enables novel synthetic effector states escaping canonical exhaustion in tumor-rejecting CD8+ T cells.

To date, no immunotherapy approaches have managed to fully overcome T-cell exhaustion, which remains a mandatory fate for chronically activated effector cells and a major therapeutic challenge. Understanding how to reprogram CD8+ tumor-infiltrating lymphocytes away from exhausted effector states remains an elusive goal. Our work provides evidence that orthogonal gene engineering of T cells to secrete an interleukin (IL)-2 variant binding the IL-2Rßγ receptor and the alarmin IL-33 reprogrammed adoptively transferred T cells to acquire a novel, synthetic effector state, which deviated from canonical exhaustion and displayed superior effector functions. These cells successfully overcame homeostatic barriers in the host and led-in the absence of lymphodepletion or exogenous cytokine support-to high levels of engraftment and tumor regression. Our work unlocks a new opportunity of rationally engineering synthetic CD8+ T-cell states endowed with the ability to avoid exhaustion and control advanced solid tumors.

Universal and Translational Nanoparticulate CpG Adjuvant.

CpG, an agonist of toll-like receptor 9 (TLR9), has become a novel adjuvant that substantially potentiates cellular immunity. However, this agonist may increase systemic toxicity by diffusing into blood after administration and is difficult to be internalized by immune cells to reach TLR9 located in endosomes as a result of the characteristics of negative charge of CpG. Here, we applied a scalable and controllable flash nanocomplexation technology to prepare nanoparticulate CpG adjuvant (npCpG), CpG encapsulated in a physical cross-linking network of protamine and TPP. The nanoadjuvant could redirect CpG into draining lymph nodes to reduce systemic diffusion to improve safety. Further, a combination of npCpG and influenza H1N1 hemagglutinin antigen showed excellent humoral and cellular immunity, evoking high levels of antibodies and cytokines and inducing a great expansion of splenocytes in immunized mice. Also, the nanoadjuvant combined with ovalbumin antigen led to a potent cytotoxic T-cell response, substantially inhibited tumor growth, and improved the survival rate of mice in a melanoma model. This study showed the universal performances of npCpG in infectious disease prevention and tumor immunotherapy to demonstrate the translational potential.

Bacteriolytic therapy with Clostridium ghonii for experimental solid tumors.

Clostridium ghonii (C. ghonii) is a non-pathogenic Clostridium species and a strictly anaerobic, spore-forming bacterium. However, its bacterial oncolytic capabilities and applications have not yet been reported. This study aimed to determining the bacterial oncolytic capability of C. ghonii for the treatment of experimental solid tumors. C. ghonii secreted collagenase IV and phospholipase c and significantly promoted apoptosis and necrosis in cultured A549 cells. C. ghonii spores specially germinated and were distributed in the tumors, and elicited the immune responses after intratumoral injection in tumor-bearing mice. C. ghonii spores decreased tumor volumes and increased tumor necrosis and inhibition rates in tumor-bearing mice. Furthermore, the combination of radiation and C. ghonii exerted additive anti-tumor effects. Taken together, our data indicate that C. ghonii is a bacteriolytic therapeutic agent against solid tumors. Given the proven natural safety of C. ghonii, it is attractive as a potential novel bacteriolytic therapy for solid tumors.

АNTIMETASTATIC EFFECT OF B. SUBTILIS IMV B-7724 LECTIN OBSERVED IN LEWIS LUNG CARCINOMA MODEL.

AIM: To study the antitumor and antimetastatic effects of B. subtilis IMV B-7724 lectin used in neoadjuvant and adjuvant settings in vivo. MATERIALS AND METHODS: Studies were performed on C57Bl/6J mice; Lewis lung carcinoma (LLC) was used as an experimental tumor. В. subtilis ІМV В-7724 lectin was administered to tumor-bearing mice or to mice which underwent surgical resection of the primary tumor. The lectin was injected subcutaneously, 10 times, at a single dose of 5 or 1 mg/kg of body weight. The standard indicators of tumor growth and metastasis were evaluated. RESULTS: Independently of the application settings, the lectin at a dose of 1 mg/kg of b.w. caused more pronounced effect than at a dose of 5 mg/kg of b.w. The administration of B. subtilis IMV B-7724 lectin to the mice with LLC in neoadjuvant setting did not cause notable antitumor effect but led to a significant decrease in the number and volume of lung metastases. The lectin administration in adjuvant setting significantly inhibited metastasis: the metastasis inhibition index reached 63.0% and 100% in the mice treated with the lectin at a dose of 5 mg/kg and 1 mg/kg respectively. The mean survival time of the treated animals significantly increased. CONCLUSION: A pronounced antimetastatic effect of B. subtilis IMV B-7724 lectin administered in an adjuvant setting was demonstrated.

Intratumoral injection of schwannoma with attenuated Salmonella typhimurium induces antitumor immunity and controls tumor growth.

Schwannomas are slow-growing benign neoplasms that develop throughout the body causing pain, sensory/motor dysfunction, and death. Because bacterial immunotherapy has been used in the treatment of some malignant neoplasms, we evaluated attenuated Salmonella typhimurium strains as immunotherapies for benign murine schwannomas. Several bacterial strains were tested, including VNP20009, a highly attenuated strain that was previously shown to be safe in human subjects with advanced malignant neoplasms, and a VNP20009 mutant that was altered in motility and other properties that included adherence and invasion of cultured mammalian cells. VNP20009 controlled tumor growth in two murine schwannoma models and induced changes in cytokine and immune effector cell profiles that were consistent with induction of enhanced innate and adaptive host immune responses compared with controls. Intratumoral (i.t.) injection of S. typhimurium led to tumor cell apoptosis, decreased tumor angiogenesis, and lower growth of the injected schwannoma tumors. Invasive VNP20009 was significantly more efficacious than was a noninvasive derivative in controlling the growth of injected tumors. Bacterial treatment apparently induced systemic antitumor immunity in that the growth of rechallenge schwannomas implanted following primary bacterial treatment was also reduced. Checkpoint programmed death-1 (PD-1) blockade induced by systemic administration of anti-PD-1 antibodies controlled tumor growth to the same degree as i.t. injection of S. typhimurium, and together, these two therapies had an additive effect on suppressing schwannoma growth. These experiments represent validation of a bacterial therapy for a benign neoplasm and support development of S. typhimurium VNP20009, potentially in combination with PD-1 inhibition, as a schwannoma immunotherapy.

Intravesical delivery of KDM6A-mRNA via mucoadhesive nanoparticles inhibits the metastasis of bladder cancer.

Lysine-specific demethylase 6A (KDM6A), also named UTX, is frequently mutated in bladder cancer (BCa). Although known as a tumor suppressor, KDM6A's therapeutic potential in the metastasis of BCa remains elusive. It also remains difficult to fulfill the effective up-regulation of KDM6A levels in bladder tumor tissues in situ to verify its potential in treating BCa metastasis. Here, we report a mucoadhesive messenger RNA (mRNA) nanoparticle (NP) strategy for the intravesical delivery of KDM6A-mRNA in mice bearing orthotopic Kdm6a-null BCa and show evidence of KDM6A's therapeutic potential in inhibiting the metastasis of BCa. Through this mucoadhesive mRNA NP strategy, the exposure of KDM6A-mRNA to the in situ BCa tumors can be greatly prolonged for effective expression, and the penetration can be also enhanced by adhering to the bladder for sustained delivery. This mRNA NP strategy is also demonstrated to be effective for combination cancer therapy with other clinically approved drugs (e.g., elemene), which could further enhance therapeutic outcomes. Our findings not only report intravesical delivery of mRNA via a mucoadhesive mRNA NP strategy but also provide the proof-of-concept for the usefulness of these mRNA NPs as tools in both mechanistic understanding and translational study of bladder-related diseases.

Selective delivery of low-affinity IL-2 to PD-1+ T cells rejuvenates antitumor immunity with reduced toxicity.

PD-1 signaling on T cells is the major pathway that limits T cell immunity, but the efficacy of anti-PD-1 therapy has been limited to a small proportion of patients with advanced cancers. We fortuitously observed that anti-PD-1 therapy depends on IL-2 signaling, which raises the possibility that a lack of IL-2 limits anti-PD-1-induced effector T cell expansion. To selectively deliver IL-2 to PD-1+CD8+ tumor-infiltrating lymphocytes (TILs), we engineered a low-affinity IL-2 paired with anti-PD-1 (PD-1-laIL-2), which reduced affinity to peripheral Treg cells but enhanced avidity to PD-1+CD8+ TILs. PD-1-laIL-2 exerted better tumor control and lower toxicity than single or mixed treatments. Mechanistically, PD-1-laIL-2 could effectively expand dysfunctional and tumor-specific CD8+ T cells. Furthermore, we discovered that presumably dysfunctional PD-1+TIM3+ TILs are the dominant tumor-specific T cells responding to PD-1-laIL-2. Collectively, these results highlight that PD-1-laIL-2 can target and reactivate tumor-specific TILs for tumor regression as a unique strategy with stronger efficacy and lower toxicity.

In vivo imaging of nanoparticle-labeled CAR T cells.

Metastatic osteosarcoma has a poor prognosis with a 2-y, event-free survival rate of ∼15 to 20%, highlighting the need for the advancement of efficacious therapeutics. Chimeric antigen receptor (CAR) T-cell therapy is a potent strategy for eliminating tumors by harnessing the immune system. However, clinical trials with CAR T cells in solid tumors have encountered significant challenges and have not yet demonstrated convincing evidence of efficacy for a large number of patients. A major bottleneck for the success of CAR T-cell therapy is our inability to monitor the accumulation of the CAR T cells in the tumor with clinical-imaging techniques. To address this, we developed a clinically translatable approach for labeling CAR T cells with iron oxide nanoparticles, which enabled the noninvasive detection of the iron-labeled T cells with magnetic resonance imaging (MRI), photoacoustic imaging (PAT), and magnetic particle imaging (MPI). Using a custom-made microfluidics device for T-cell labeling by mechanoporation, we achieved significant nanoparticle uptake in the CAR T cells, while preserving T-cell proliferation, viability, and function. Multimodal MRI, PAT, and MPI demonstrated homing of the T cells to osteosarcomas and off-target sites in animals administered with T cells labeled with the iron oxide nanoparticles, while T cells were not visualized in animals infused with unlabeled cells. This study details the successful labeling of CAR T cells with ferumoxytol, thereby paving the way for monitoring CAR T cells in solid tumors.

Relieving immunosuppression by Endo@PLT targeting anti-angiogenesis to improve the efficacy of immunotherapies.

Low levels of immune infiltrates in the tumor milieu hinder the effectiveness of immunotherapy against immune-cold tumors. In the current work, a tumor-targeting drug delivery system composed of Endo-loaded platelets (Endo@PLT) was developed to relieve immunosuppression by achieving tumor vascular normalization. Endo@PLT reprogrammed the immunostimulatory phenotype, achieving excellent PD-1 immunotherapy in vivo.

Natural Small Molecules Enabled Efficient Immunotherapy through Supramolecular Self-Assembly in P53-Mutated Colorectal Cancer.

Nanomedicine, constructed from therapeutics, presents an advantage in drug delivery for cancer therapies. However, nanocarrier-based treatment systems have problems such as interbatch variability, multicomponent complexity, poor drug delivery, and carrier-related toxicity. To solve these issues, the natural molecule honokiol (HK), an anticancer agent in a phase I clinical trial (CTR20170822), was used to form a self-assembly nanoparticle (SA) through hydrogen bonding and hydrophobicity. The preparation of SA needs no molecular precursors or excipients in aqueous solution, and 100% drug-loaded SA exhibited superior tumor-targeting ability due to the enhanced permeability and retention (EPR) effect. Moreover, SA significantly enhanced the antitumor immunity relative to free HK, and the mechanism has notable selectivity to the p53 pathway. Furthermore, SA exhibited excellent physiological stability and inappreciable toxicity. Taken together, this supramolecular self-assembly strategy provides a safe and "molecular economy" model for rational design of clinical therapies and is expected to promote targeted therapy of HK, especially in colorectal cancer patients with obvious p53 status.

A "Double-Locked" and Enzyme/pH-Activated Theranostic Agent for Accurate Tumor Imaging and Therapy.

Theranostic agents for concurrent cancer therapy and diagnosis have begun attracting attention as a promising modality. However, accurate imaging and identification remains a great challenge for theranostic agents. Here, we designed and synthesized a novel theranostic agent H6M based on the "double-locked" strategy by introducing an electron-withdrawing nitro group into 1-position of a pH-responsive 3-amino-ß-carboline and further covalently linking the hydroxamic acid group, a zinc-binding group (ZBG), to the 3-position of ß-carboline to obtain histone deacetylase (HDAC) inhibitory effect for combined HDAC-targeted therapy. We found that H6M can be specifically reduced under overexpressed nitroreductase (NTR) to produce H6AQ, which emits bright fluorescence at low pH. Notably, H6M demonstrated a selective fluorescence imaging via successive reactions with NTR (first "key") and pH (second "key"), and precisely identified tumor margins with a high S/N ratio to guide tumor resection. Finally, H6M exerted robust HDAC1/cancer cell inhibitory activities compared with a known HDAC inhibitor SAHA. Therefore, the NTR/pH-activated theranostic agent provided a novel tool for precise diagnosis and efficient tumor therapy.

In vitro and in vivo MRI imaging and photothermal therapeutic properties of Hematite (α-Fe2O3) Nanorods.

Herein we report synthesis of hematite (α-Fe2O3) nanorods by calcinating hydrothermally synthesized goethite nanorods at 5000C. The structural, optical and MRI imaging guided cancer therapeutic properties of fabricated nanorods have been discussed in this manscript. FESEM and TEM imaging techniques were used to confirm the nanorod like morphology of as prepared materials. As we know that Fe2O3 nanorods with size in the range of 25-30 nm exhibit super magnetism. After coating with the PEG, the as prepared nanorods can be used as T2 MR imaging contrast agents. An excellent T2 MRI contrast of 38.763 mM-1s-1 achieved which is highest reported so far for α-Fe2O3. Besides the as prepared nanorods display an excellent photothermal conversion efficiency of 39.5% thus acts as an excellent photothermal therapeutic agent. Thus, we envision the idea of testing our nanorods for photothermal therapy and MR imaging application both in vitro and in vivo, achieving an excellent T2 MRI contrast and photothermal therapy effect with as prepared PEGylated nanorods.

Complement C1q binding protein regulates T cells' mitochondrial fitness to affect their survival, proliferation, and anti-tumor immune function.

T cells survival, proliferation, and anti-tumor response are closely linked to their mitochondrial health. Complement C1q binding protein (C1QBP) promotes mitochondrial fitness through regulation of mitochondrial metabolism and morphology. However, whether C1QBP regulates T cell survival, proliferation, and anti-tumor immune function remains unclear. Our data demonstrated that C1QBP knockdown induced the accumulation of reactive oxygen species (ROS) and the loss of mitochondrial membrane potential to impair T cell mitochondrial fitness. At the same time, C1QBP insufficiency reduced the recruitment of the anti-apoptotic proteins, including Bcl-2 and Bcl-XL, and repressed caspase-3 activation and poly (ADP-ribose) polymerase cleavage, which consequently accelerated the T cell apoptotic process. In contrast, C1QBP knockdown rendered T cells with relatively weaker proliferation due to the inhibition of AKT/mTOR signaling pathway. To investigate the exact role of C1QBP in anti-tumor response, C1QBP+/- and C1QBP+/+ mice were given a subcutaneous injection of murine MC38 cells. We found that C1QBP deficiency attenuated T cell tumor infiltration and aggravated tumor-infiltrating T lymphocytes (TIL) exhaustion. Moreover, we further clarified the potential function of C1QBP in chimeric antigen receptor (CAR) T cell immunotherapy. Our data showed that C1QBP+/- CAR T cells exhibited relatively weaker anti-tumor response than the corresponding C1QBP+/+ CAR T cells. Given that C1QBP knockdown impairs T cells' anti-apoptotic capacity, proliferation as well as anti-tumor immune function, development of the strategy for potentiation of T cells' mitochondrial fitness through C1QBP could potentially optimize the efficacy of the related immunotherapy.

Combination of tucatinib and neural stem cells secreting anti-HER2 antibody prolongs survival of mice with metastatic brain cancer.

Brain metastases are a leading cause of death in patients with breast cancer. The lack of clinical trials and the presence of the blood-brain barrier limit therapeutic options. Furthermore, overexpression of the human epidermal growth factor receptor 2 (HER2) increases the incidence of breast cancer brain metastases (BCBM). HER2-targeting agents, such as the monoclonal antibodies trastuzumab and pertuzumab, improved outcomes in patients with breast cancer and extracranial metastases. However, continued BCBM progression in breast cancer patients highlighted the need for novel and effective targeted therapies against intracranial metastases. In this study, we engineered the highly migratory and brain tumor tropic human neural stem cells (NSCs) LM008 to continuously secrete high amounts of functional, stable, full-length antibodies against HER2 (anti-HER2Ab) without compromising the stemness of LM008 cells. The secreted anti-HER2Ab impaired tumor cell proliferation in vitro in HER2+ BCBM cells by inhibiting the PI3K-Akt signaling pathway and resulted in a significant benefit when injected in intracranial xenograft models. In addition, dual HER2 blockade using anti-HER2Ab LM008 NSCs and the tyrosine kinase inhibitor tucatinib significantly improved the survival of mice in a clinically relevant model of multiple HER2+ BCBM. These findings provide compelling evidence for the use of HER2Ab-secreting LM008 NSCs in combination with tucatinib as a promising therapeutic regimen for patients with HER2+ BCBM.

Design, synthesis and biological evaluation studies of novel small molecule ENPP1 inhibitors for cancer immunotherapy.

Ecto-nucleotide pyrophosphatase/phosphodiesterases 1 (ENPP1 or NPP1), is an attractive therapeutic target for various diseases, primarily cancer and mineralization disorders. The ecto-enzyme is located on the cell surface and has been implicated in the control of extracellular levels of nucleotide, nucleoside and (di) phosphate. Recently, it has emerged as a critical phosphodiesterase that hydrolyzes cyclic 2'3'- cGAMP, the endogenous ligand for STING (STimulator of INterferon Genes). STING plays an important role in innate immunity by activating type I interferon in response to cytosolic 2'3'-cGAMP. ENPP1 negatively regulates the STING pathway and hence its inhibition makes it an attractive therapeutic target for cancer immunotherapy. Herein, we describe the design, optimization and biological evaluation studies of a series of novel non-nucleotidic thioguanine based small molecule inhibitors of ENPP1. The lead compound 43 has shown good in vitro potency, stability in SGF/SIF/PBS, selectivity, ADME properties and pharmacokinetic profile and finally potent anti-tumor response in vivo. These compounds are a good starting point for the development of potentially effective cancer immunotherapy agents.

Cancer immunotherapy using artificial adjuvant vector cells to deliver NY-ESO-1 antigen to dendritic cells in situ.

NY-ESO-1 is a cancer/testis antigen expressed in various cancer types. However, the induction of NY-ESO-1-specific CTLs through vaccines is somewhat difficult. Thus, we developed a new type of artificial adjuvant vector cell (aAVC-NY-ESO-1) expressing a CD1d-NKT cell ligand complex and a tumor-associated antigen, NY-ESO-1. First, we determined the activation of invariant natural killer T (iNKT) and natural killer (NK) cell responses by aAVC-NY-ESO-1. We then showed that the NY-ESO-1-specific CTL response was successfully elicited through aAVC-NY-ESO-1 therapy. After injection of aAVC-NY-ESO-1, we found that dendritic cells (DCs) in situ expressed high levels of costimulatory molecules and produced interleukn-12 (IL-12), indicating that DCs undergo maturation in vivo. Furthermore, the NY-ESO-1 antigen from aAVC-NY-ESO-1 was delivered to the DCs in vivo, and it was presented on MHC class I molecules. The cross-presentation of the NY-ESO-1 antigen was absent in conventional DC-deficient mice, suggesting a host DC-mediated CTL response. Thus, this strategy helps generate sufficient CD8+ NY-ESO-1-specific CTLs along with iNKT and NK cell activation, resulting in a strong antitumor effect. Furthermore, we established a human DC-transferred NOD/Shi-scid/IL-2γcnull immunodeficient mouse model and showed that the NY-ESO-1 antigen from aAVC-NY-ESO-1 was cross-presented to antigen-specific CTLs through human DCs. Taken together, these data suggest that aAVC-NY-ESO-1 has potential for harnessing innate and adaptive immunity against NY-ESO-1-expressing malignancies.