Oncolytic mineralized bacteria as potent locally administered immunotherapeutics.

Oncolytic bacteria can trigger innate immune activity. However, the antitumour efficacy of inactivated bacteria is poor, and attenuated live bacteria pose substantial safety risks. Here we show that intratumourally injected paraformaldehyde-fixed bacteria coated with manganese dioxide potently activate innate immune activity, modulate the immunosuppressive tumour microenvironment and trigger tumour-specific immune responses and abscopal antitumour responses. A single intratumoural administration of mineralized Salmonella typhimurium suppressed the growth of multiple types of subcutaneous and orthotopic tumours in mice, rabbits and tree shrews and protected the cured animals against tumour rechallenge. We also show that mineralized bacteria can be administered via arterial embolization to treat orthotopic liver cancer in rabbits. Our findings support the further translational testing of oncolytic mineralized bacteria as potent and safe antitumour immunotherapeutics.

Money or funny: Effective connectivity during service recovery with a DCM-PEB approach.

While monetary compensation is considered the most effective service recovery strategy, relief theory claims that humor may also be useful in service recovery situations. This study investigated the effects of humor in service recovery using dynamic causal modeling and parametric empirical Bayes analysis to identify effective connectivity (EC) patterns in the dopaminergic reward system across four conditions representing different service recovery strategies: monetary compensation and humor (MH), monetary compensation and an apology (MA), non-monetary compensation using humor (H), and non-monetary compensation using an apology (CON, the control condition). The findings support the importance of the nucleus accumbens (NAc) in the monetary compensation (MH and MA) conditions and the amygdala in the non-monetary compensation (H and CON) conditions. Monetary compensation (MH and MA) resulted in right substantia nigra (rSN) to NAc EC, suggesting the processing of recovery satisfaction associated with perceived outcome fairness. Conversely, non-monetary compensation strategies (H and CON) resulted in left substantia nigra (lSN) to amygdala EC, suggesting the processing of satisfaction related to perceived interactional fairness. The use of humor for service recovery resulted in VTA-to-lSN-to-amygdala EC during humor appreciation, while the use of apologies (CON and MA) resulted in lSN-to-amygdala and lSN-to-VTA connectivity. Surprisingly, processing satisfaction in the MH condition did not activate the amygdala during humor appreciation. Coping humor could be norm-violating for service recovery, and its effectiveness depends on multiple factors. The results suggest that monetary compensation, humorous responses, and apologies play key roles in neurological responses to service recovery strategies.

Coupling programmed cell death 1-positive tumor-infiltrating T cells with anti-programmed cell death 1 antibody improves the efficacy of adoptive T-cell therapy.

BACKGROUND AIMS: Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) has shown great success in clinical trials. Programmed cell death 1 (PD-1)-expressing TILs show high specificity to autologous tumor cells. However, limited therapeutic efficiency is observed as a result of the tumor immune microenvironment (TIME). METHODS: Coupling PD-1+ex vivo-derived TILs with a monoclonal antibody against anti-PD-1 (aPD-1) reinvigorated the anti-tumor response of TILs against solid tumor without altering their high tumor targeting ability. RESULTS: Using a melanoma-bearing mouse model, PD-1+ TILs blocked with aPD-1 (PD-1+ TILs-aPD-1) exhibited a high capability for tumor targeting as well as improved anti-tumor response in TIME. Tumor growth was substantially delayed in the mice treated with PD-1+ TILs-aPD-1. CONCLUSIONS: The strategy utilizing TIL therapy coupled with immune checkpoint antibodies may extend to other therapeutic targets of ACT.

A general strategy towards personalized nanovaccines based on fluoropolymers for post-surgical cancer immunotherapy.

Cancer metastases and recurrence after surgical resection remain an important cause of treatment failure. Here we demonstrate a general strategy to fabricate personalized nanovaccines based on a cationic fluoropolymer for post-surgical cancer immunotherapy. Nanoparticles formed by mixing the fluoropolymer with a model antigen ovalbumin, induce dendritic cell maturation via the Toll-like receptor 4 (TLR4)-mediated signalling pathway, and promote antigen transportation into the cytosol of dendritic cells, which leads to an effective antigen cross-presentation. Such a nanovaccine inhibits established ovalbumin-expressing B16-OVA melanoma. More importantly, a mix of the fluoropolymer with cell membranes from resected autologous primary tumours synergizes with checkpoint blockade therapy to inhibit post-surgical tumour recurrence and metastases in two subcutaneous tumour models and an orthotopic breast cancer tumour. Furthermore, in the orthotopic tumour model, we observed a strong immune memory against tumour rechallenge. Our work offers a simple and general strategy for the preparation of personalized cancer vaccines to prevent post-operative cancer recurrence and metastasis.

Photosensitizer-Modified MnO2 Nanoparticles to Enhance Photodynamic Treatment of Abscesses and Boost Immune Protection for Treated Mice.

The emergence of drug-resistant bacteria and easy recurrence has been challenging in the clinical treatment of skin abscesses resulting from bacterial infections (e.g., by Staphylococcus aureus (S. aureus)). Herein, an antibacterial nanoagent capable of modulating the abscess microenvironment is designed to enhance photodynamic treatment of skin abscesses, and subsequently activate the immune system to effectively prevent abscess recurrence. In the system, manganese dioxide nanoparticles (MnO2 NPs) with high catalytic reactivity toward H2 O2 are modified with photosensitizer chlorine e6 (Ce6) and coated with polyethylene glycol (PEG). The obtained Ce6@MnO2 -PEG NPs, by triggering the decomposition of lesion endogenous H2 O2 , are able to effectively relieve the hypoxic abscess microenvironment during S. aureus infection. The light-triggered photodynamic bacterial killing effect could thus be remarkably enhanced, resulting in effective in vivo therapy of S. aureus-induced skin abscesses. Interestingly, a notable pathogen-specific immunological memory effect against future infection by the same species of bacteria is elicited after such treatment, owing to the release of bacterial antigens post photodynamic therapy (PDT) together with the adjuvant-like function of manganese ions to activate the host immune system. This work thus presents a new type of photodynamic nanoagent particularly promising for highly effective light-triggered abscess treatment and prevention of abscess recurrence.

Facile Preparation of Cu2Se Nanosheets as Dual-Functional Antibacterial Agents.

The spread of antibiotic-resistance poses a great threat, making it a growing need to develop other antibacterial strategies and therapeutics. Recently, owing to their excellent physicochemical properties, copper chalcogenides have received extensive attention as photothermal agents. However, most reports are focused on Cu2-xS nanoparticles, whereas very few water-dispersible Cu2-xSe nanomaterials have been reported due to their difficult preparation process. Herein, water-dispersible and biocompatible cuprous selenide nanosheets (Cu2Se NSs) were synthesized by a simple anion exchange method starting from cuprous oxide nanorods (Cu2O NRs), which could also help avoid any environmental pollution caused by the organic solvent used during synthesis. The obtained Cu2Se NSs showed strong absorption in the second near-infrared window (NIR II) with a good photothermal conversion efficiency as high as ∼61.16%, outstanding among the previously reported NIR II photothermal agents. Interestingly, using Staphylococcus aureus and Escherichia coli as model pathogens, these Cu2Se NSs possess an intrinsic bacteriostatic effect and could inhibit the growth of both bacteria species. Furthermore, both the fluorescent-based microscopy and the bacterial morphology analysis using a scanning electron microscope have demonstrated that incubation of both species of bacteria with Cu2Se NSs under laser irradiation (1064 nm) would lead to complete disruption of the bacterial cell wall. Our work presents a facile method to prepare water-dispersible Cu2Se NSs-, which could serve as highly efficient dual-functional antibacterial agents.

Cell-Penetrating Peptide Enhanced Antigen Presentation for Cancer Immunotherapy.

The development of effective cancer vaccines is an important direction in the area of cancer immunotherapy. Although certain types of preventive cancer vaccines have already been used in the clinic, therapeutic cancer vaccines for treatment of already established tumors are still in high demand. In this study, we develop a new type of cancer vaccine by mixing cell-penetrating peptide (CPP) conjugated antigen as the enhanced antigen, together with CpG as the immune adjuvant. A special CPP, cytosol-localizing internalization peptide 6 (CLIP6), which has the ability to enter cells exclusively via a nonendosomal mechanism, i.e., direct translocation across the cell membrane, is conjugated with model antigen ovalbumin (OVA). Compared to naked OVA, the obtained CLIP6-OVA conjugates show greatly increased uptake by dendritic cells (DCs) and, more importantly, remarkably enhanced antigen cross-presentation, eliciting stronger cytotoxic T lymphocyte (CTL) mediated immune responses with the help of CpG. This CLIP6-OVA/CpG formulation offers effective protection for mice against challenged B16-OVA tumors, and is able to further function as a therapeutic vaccine, which, in combination with immune checkpoint blockade therapy, can significantly suppress the already-established tumors. Such a CLIP6-based cancer vaccine developing strategy shows promising potential toward clinical practice owing to its features of easy preparation, low cost, and remarkable biocompatibility.

Nanovaccine based on a protein-delivering dendrimer for effective antigen cross-presentation and cancer immunotherapy.

Cancer vaccines for prevention and treatment of tumors have attracted tremendous interests as a type of cancer immunotherapy strategy. A major challenge in achieving robust T-cell responses to destruct tumor cells after vaccination is the abilities of antigen cross-presentation for antigen-presenting cells (APCs) such as dendritic cells (DCs). Herein, we demonstrate that a polyamidoamine dendrimer modified with guanidinobenzoic acid (DGBA) could serve as an effective protein carrier to enable delivery of protein antigen, thereby leading to effective antigen cross-presentation by DCs. With ovalbumin (OVA) as the model antigen and unmethylated cytosine-guanine dinucleotides (CpG) as the adjuvant, a unique type of tumor vaccine is formulated. Importantly, such DGBA-OVA-CpG nanovaccine can induce robust antigen-specific cellular immunities and further demonstrates outstanding prophylactic efficacy against B16-OVA melanoma. More significantly, the nanovaccine shows excellent therapeutic effect to treat established B16-OVA melanoma when used in combination with the programmed cell death protein 1 (PD-1) checkpoint-blockade immunotherapy. This study presents the great promises of employing rationally engineered cytosolic protein carriers for the development of tumor vaccines to achieve effective cancer immunotherapy.

Near-Infrared-Triggered Photodynamic Therapy with Multitasking Upconversion Nanoparticles in Combination with Checkpoint Blockade for Immunotherapy of Colorectal Cancer.

While immunotherapy has become a highly promising paradigm for cancer treatment in recent years, it has long been recognized that photodynamic therapy (PDT) has the ability to trigger antitumor immune responses. However, conventional PDT triggered by visible light has limited penetration depth, and its generated immune responses may not be robust enough to eliminate tumors. Herein, upconversion nanoparticles (UCNPs) are simultaneously loaded with chlorin e6 (Ce6), a photosensitizer, and imiquimod (R837), a Toll-like-receptor-7 agonist. The obtained multitasking UCNP-Ce6-R837 nanoparticles under near-infrared (NIR) irradiation with enhanced tissue penetration depth would enable effective photodynamic destruction of tumors to generate a pool of tumor-associated antigens, which in the presence of those R837-containing nanoparticles as the adjuvant are able to promote strong antitumor immune responses. More significantly, PDT with UCNP-Ce6-R837 in combination with the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) checkpoint blockade not only shows excellent efficacy in eliminating tumors exposed to the NIR laser but also results in strong antitumor immunities to inhibit the growth of distant tumors left behind after PDT treatment. Furthermore, such a cancer immunotherapy strategy has a long-term immune memory function to protect treated mice from tumor cell rechallenge. This work presents an immune-stimulating UCNP-based PDT strategy in combination with CTLA-4 checkpoint blockade to effectively destroy primary tumors under light exposure, inhibit distant tumors that can hardly be reached by light, and prevent tumor reoccurrence via the immune memory effect.

Protective effects of five allium derived organosulfur compounds against mutation and oxidation.

In this study, we examined the ability of five allium-derived organosulfur compounds to protect cells against mutation and oxidation. The compounds tested were 1-propylmercaptan (PM), dimethyl disulfide (DMDS), diallyl disulfide (DADS), propyl disulfide (PDS), and 2,5-dimethylthiophene (DMT). Our results showed that when used at concentrations of 100-400 µmol/l, the five compounds inhibited the mutagenicity of 4-nitroquinoline-N-oxide, a direct mutagen, and benzo[a]pyrene, an indirect mutagen, toward Salmonella typhimurium TA 98 and TA 100. Furthermore, at these concentrations, all five of the compounds protected HepG2 cells against tert-butyl hydroperoxide-induced oxidative cytotoxicity. The compounds likely enhanced cell viability by suppressing the formation of reactive oxygen species and the depletion of glutathione depletion in cells. DMT and PM inhibited mutation and oxidation to a greater extent than DMDS, DADS, and PDS. These results demonstrate for the first time that DMT and PM can contribute to the antimutagenic and the antioxidative property of Allium vegetables.

[Inhibitory effect of all-trans-retinoid and polyphenon-100 on microsatellite instability in a colon cancer line].

OBJECTIVE: To investigate the effects of all-trans-retinoic acid(ATRA) and polyphenon-100 (PP) on genetic instability of human tumor cells via their role in alteration of microsatellite sequence(MS) and the expression of mismatch repair gene hMLH(1) and hMSH(2) in RER(+) (replication error) cells. METHODS: RER(+) colon cancer cell line was used as a host for lipofection with pCMV-CAR in which a foreign (CA)(14) repeat was inserted in the coding sequence of LacZ reporter gene, resulting in misreading LacZ frame. Any mutation which made the base number of (CA)(14) tract to be 3-fold resumed normal reading frame of LacZ, and thus led to expression of beta-galactosidase. Variable expression of LacZ in the transfectant cells resulting from RATA or PP treatment was measured by OD reading at lambda 620 after X-gal staining. Expression of mismatch repair genes of hMLH(1) and hMSH(2) was examined at mRNA level by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: ATRA at 1 mu mol/L, 0.1 u mol/L and PP at 3 mu g/ml had no significant inhibitory effect on cell proliferation. After being treated with ATRA or PP for 1 week, the blue cells of RKO transfectant clones were significantly reduced, and this meant the mutation of exogenous (CA)(14) in RKO cells were inhibited. But no expression of hMLH(1) and hMSH(2) was observed. CONCLUSION: The above data showed both ATRA and PP had inhibitory effects on MS instability of cancer and thus demonstrated directly their beneficial role in stabilization of genomic DNA. However, the present authors have not observed any expression of hMLH(1) and hMSH(2) in RKO cells treated with ATRA or PP.

Comparison of breast mammography, sonography and physical examination for screening women at high risk of breast cancer in taiwan.

Recommended surveillance for screening breast cancer, which includes regular mammography and clinical breast examination, has long been established in Western countries. This strategy may be too costly and unnecessary for countries with low incidences of breast cancer. The purpose of the present study is to compare breast mammography, sonography and physical examination in screening female relatives of breast cancer index cases from the hospital, and their relative efficiency. A total of 935 women over 35 years old, who were relatives of breast cancer patients, were invited to an annual screening by means of a combination of mammography, sonography and physical examination on a single day. A biopsy was performed when any of the three investigations indicated a possibility of malignancy. A total of 21 breast cancers, including sixteen invasive cancers and 5 noninvasive cancers, were detected among the 935 high-risk women. Of the cancers, 18, including 16 invasive cancers and 3 noninvasive cancers, were detected by sonography. In contrast, only 11 invasive cancers were detected by mammography, and 7 by physical examination. There were only 14 cancers detected by a combination of mammography and physical examination. The 7 (33.3%) additional cancers were detected when sonography was added. The sensitivity of sonography was 90.4%, which was higher than mammography (52.4%) and physical examination (33.3%), or even a combination of these two modalities (66.7%). This indicates that sonography is a more accurate screening tool for breast cancer in the high-risk group. Although breast sonography has not yet been recommended as a routine screening tool for breast cancer in Western countries, it may be superior to mammography and physical examination for the screening of Taiwanese high-risk female relatives of breast cancer index cases. If it should also be considered as a routine adjunct screening modality for Taiwanese women with lower rates of breast cancer will need further study.