Self-Assembled STING-Activating Coordination Nanoparticles for Cancer Immunotherapy and Vaccine Applications.

The cGAS-STING pathway plays a crucial role in innate immune activation against cancer and infections, and STING agonists based on cyclic dinucleotides (CDN) have garnered attention for their potential use in cancer immunotherapy and vaccines. However, the limited drug-like properties of CDN necessitate an efficient delivery system to the immune system. To address these challenges, we developed an immunostimulatory delivery system for STING agonists. Here, we have examined aqueous coordination interactions between CDN and metal ions and report that CDN mixed with Zn2+ and Mn2+ formed distinctive crystal structures. Further pharmaceutical engineering led to the development of a functional coordination nanoparticle, termed the Zinc-Mn-CDN Particle (ZMCP), produced by a simple aqueous one-pot synthesis. Local or systemic administration of ZMCP exerted robust antitumor efficacy in mice. Importantly, recombinant protein antigens from SARS-CoV-2 can be simply loaded during the aqueous one-pot synthesis. The resulting ZMCP antigens elicited strong cellular and humoral immune responses that neutralized SARS-CoV-2, highlighting ZMCP as a self-adjuvant vaccine platform against COVID-19 and other infectious pathogens. Overall, this work establishes a paradigm for developing translational coordination nanomedicine based on drug-metal ion coordination and broadens the applicability of coordination medicine for the delivery of proteins and other biologics.

A point mutation in the meiotic crossover formation gene HEI10/TFS2 leads to thermosensitive genic sterility in rice.

Thermosensitive genic female sterility (TGFS) is a promising property to be utilized for hybrid breeding. Here, we identified a rice TGFS line, tfs2, through an ethyl methyl sulfone (EMS) mutagenesis strategy. This line showed sterility under high temperature and became fertile under low temperature. Few seeds were produced when the tfs2 stigma was pollinated, indicating that tfs2 is female sterile. Gene cloning and genetic complementation showed that a point mutation from leucine to phenylalanine in HEI10 (HEI10tfs2), a crossover formation protein, caused the TGFS trait of tfs2. Under high temperature, abnormal univalents were formed, and the chromosomes were unequally segregated during meiosis, similar to the reported meiotic defects in oshei10. Under low temperature, the number of univalents was largely reduced, and the chromosomes segregated equally, suggesting that crossover formation was restored in tfs2. Yeast two-hybrid assays showed that HEI10 interacted with two putative protein degradation-related proteins, RPT4 and SRFP1. Through transient expression in tobacco leaves, HEI10 were found to spontaneously aggregate into dot-like foci in the nucleus under high temperature, but HEI10tfs2 failed to aggregate. In contrast, low temperature promoted HEI10tfs2 aggregation. This result suggests that protein aggregation at the crossover position contributes to the fertility restoration of tfs2 under low temperature. In addition, RPT4 and SRFP1 also aggregated into dot-like foci, and these aggregations depend on the presence of HEI10. These findings reveal a novel mechanism of fertility restoration and facilitate further understanding of HEI10 in meiotic crossover formation.

Effects of anterolateral femoral free flap transplantation on the repair of soft tissue defect of hands and feet and risk factors for flap necrosis.

OBJECTIVE: To retrospectively analyze the effect of anterolateral femoral free flap transplantation in repairing hand and foot soft tissue defects and the risk factors for skin flap necrosis. METHODS: The clinical data of 62 patients with hand and foot soft tissue defects admitted to Department of Hand and Foot Microsurgery in Yuyao People's Hospital of Zhejiang Province from January 2018 to December 2021 were retrospectively analyzed. According to the different methods of skin flap transplantation, these patients were divided into a control group (n=30, conventional skin flap transplantation) and an observation group (n=32, anterolateral femoral free skin flap transplantation). The clinical outcomes and postoperative flap survival rate were compared between the two groups. The risk factors of flap necrosis were analyzed by univariate and multivariate Logistic regression. RESULTS: The surgical time, intraoperative blood loss and hospital stay in the observation group were significantly less than those in the control group (all P<0.05). The survival rate of skin flap in the observation group was significantly higher than in the control group (P<0.05). Logistic regression analysis showed that intraoperatively incomplete hemostasis, inappropriate selection of anastomotic vessels, irrational use of antibiotics, infection and unstable fixation were independent risk factors for skin flap necrosis following hand and foot soft tissue defects surgery. CONCLUSION: Anterolateral femoral free flap transplantation is beneficial to improve the clinical outcomes in patients with hand or foot soft tissue defects, increase the survival rate of skin flap and promote recovery. Incomplete hemostasis during operation, inappropriate choice of anastomotic vessels, irrational application of antibiotics, concurrent infection and unstable fixation are independent risk factors for postoperative flap necrosis.

A comparison between anterolateral thigh perforator flap and abdominal pedicle flap in repair of hand injuries and tissue defects.

The purpose of this study was to compare the outcome of anterolateral thigh perforator flap and abdominal pedicled flap repair for treating traumatic tissue defects of the hand. A total of 140 patients with hand trauma tissue defects were randomly divided (random number table) into Group A and Group B, with 70 cases in each group. Group A was given anterolateral thigh perforator flap repair, while Group B was given abdominal pedicled flap repair. The healing time of wounds in Group A was noted to be shorter than that in Group B (p<0.001). At one week after surgery, VAS score, serum IL-6 and TNF-α levels in Group A were 4 times lower than those in Group B (p<0.001 for all). Anterolateral thigh perforator flap repair works more effectively on traumatic tissue defects of the hands than abdominal pedicled flap repair. It reduces pain, shortens wound healing time, and lowers serum IL-6 and TNF-α levels.

Computed Tomography Angiography and B-Mode Ultrasonography under Artificial Intelligence Plaque Segmentation Algorithm in the Perforator Localization for Preparation of Free Anterolateral Femoral Flap.

This research was aimed to investigate the accuracy of U-shaped network (UNet)-based computed tomography angiography (CTA) and B-mode ultrasonography (US) in the perforator localization of free anterolateral thigh flap (ALTF). Based on UNet, a fusion of deep supervision mechanism, squeeze-and-excitation module, and attention mechanism was introduced to optimize the algorithm. Then, a CTA segmentation model, DA-UNet, was established. The segmentation performance of DA-UNet and other algorithms was compared under the same conditions. 30 patients who were planned to receive ALTF surgery were selected as the research objects. According to different preoperative localization methods, they were divided into group A (CTA) and group B (B-mode US), 15 cases in each group. Combined with the actual situation during surgery, the diagnostic accordance rate, sensitivity (Sen), specificity, and the distance between the perforator location and the actual location were compared between the two groups. The Dice coefficient, Jaccard index, Sen, the area under curve (AUC), and average Hausdorff distance (AVD) of the DA-UNet segmentation algorithm were 80.70%, 69.97%, 77.56%, 0.887, and 2.48, respectively. These results were significantly better than those of other algorithms (P < 0.05). In group A, the diagnostic accordance rate, Sen, and specificity of patients were 96.55%, 90.52%, and 73.58%, respectively, which were higher than 91.53%, 81.36%, and 15.60% of patients in group B significantly (P < 0.05). There was no statistical difference in the distance between the perforator location and the actual location (P > 0.05). It showed that the accuracy of CTA under the UNet-based DA-UNet segmentation model in the perforator localization of ALTF was better than that of B-mode US. Thus, a reference could be provided for the preparation of free ALTF and its clinical application.

A retrotransposon insertion in MUTL-HOMOLOG 1 affects wild rice seed set and cultivated rice crossover rate.

Wild rice (Oryza rufipogon) has a lower panicle seed setting rate (PSSR) and gamete fertility than domesticated rice (Oryza sativa), but the genetic mechanisms of this phenomenon remain unknown. Here, we cloned a null allele of OsMLH1, an ortholog of MutL-homolog 1 to yeast and mammals, from wild rice O. rufipogon W1943 and revealed a 5.4-kb retrotransposon insertion in OsMLH1 is responsible for the low PSSR in wild rice. In contrast to the wild-type, a near isogenic line NIL-mlh1 exhibits defective crossover (CO) formation during meiosis, resulting in reduced pollen viability, partial embryo lethality, and low PSSR. Except for the mutant of mismatch repair gene postmeiotic segregation 1 (Ospms1), all other MutL mutants from O. sativa indica subspecies displayed male and female semi-sterility similar to NIL-mlh1, but less severe than those from O. sativa japonica subspecies. MLH1 and MLH3 did not contribute in an additive fashion to fertility. Two types of MutL heterodimers, MLH1-PMS1 and MLH1-MLH3, were identified in rice, but only the latter functions in promoting meiotic CO formation. Compared to japonica varieties, indica cultivars had greater numbers of CO events per meiosis. Our results suggest that low fertility in wild rice may be caused by different gene defects, and indica and japonica subspecies have substantially different CO rates responsible for the discrepancy between the fertility of mlh1 and mlh3 mutants.

Self-Blockade of PD-L1 with Bacteria-Derived Outer-Membrane Vesicle for Enhanced Cancer Immunotherapy.

The checkpoint inhibitor therapy that blocks programmed death-1 (PD-1) and its major ligand PD-L1 has achieved encouraging clinical efficacy in certain cancers. However, the binding of checkpoint inhibitors with other immune cells that express PD-L1 often results in a low response rate to the blockade and severe adverse effects. Herein, an LyP1 polypeptide-modified outer-membrane vesicle (LOMV) loaded with a PD-1 plasmid is developed to achieve self-blockade of PD-L1 in tumor cells. The nanocarriers accumulate in the tumor tissue through OMV-targeting ability and are internalized into the tumor cells via the LyP1-mediated target, subsequently delivering PD-1 plasmid into the nucleus, leading to the expression of PD-1 by the tumor cells. In addition, a magnetic particle chemiluminescence kit is developed to quantitatively detect the binding rate of PD-1/PD-L1. The self-expressed PD-1 bonded with the PD-L1 is expressed by both autologous and neighboring tumor cells, achieving self-blockade. Simultaneously, the outer-membrane protein of LOMV recruits cytotoxic lymphocyte cells and natural killer cells to tumor tissues and stimulates them to secrete IFN-γ  , improving the antitumor activity of the PD-1/PD-L1 self-blocking therapy.

Generation of systemic antitumour immunity via the in situ modulation of the gut microbiome by an orally administered inulin gel.

The performance of immune-checkpoint inhibitors, which benefit only a subset of patients and can cause serious immune-related adverse events, underscores the need for strategies that induce T-cell immunity with minimal toxicity. The gut microbiota has been implicated in the outcomes of patients following cancer immunotherapy, yet manipulating the gut microbiome to achieve systemic antitumour immunity is challenging. Here we show in multiple murine tumour models that inulin-a widely consumed dietary fibre-formulated as a 'colon-retentive' orally administered gel can effectively modulate the gut microbiome in situ, induce systemic memory-T-cell responses and amplify the antitumour activity of the checkpoint inhibitor anti-programmed cell death protein-1 (α-PD-1). Orally delivered inulin-gel treatments increased the relative abundances of key commensal microorganisms and their short-chain-fatty-acid metabolites, and led to enhanced recall responses for interferon-γ+CD8+ T cells as well as to the establishment of stem-like T-cell factor-1+PD-1+CD8+ T cells within the tumour microenvironment. Gels for the in situ modulation of the gut microbiome may be applicable more broadly to treat pathologies associated with a dysregulated gut microbiome.

Subtelomeric assembly of a multi-gene pathway for antimicrobial defense compounds in cereals.

Non-random gene organization in eukaryotes plays a significant role in genome evolution. Here, we investigate the origin of a biosynthetic gene cluster for production of defence compounds in oat-the avenacin cluster. We elucidate the structure and organisation of this 12-gene cluster, characterise the last two missing pathway steps, and reconstitute the entire pathway in tobacco by transient expression. We show that the cluster has formed de novo since the divergence of oats in a subtelomeric region of the genome that lacks homology with other grasses, and that gene order is approximately colinear with the biosynthetic pathway. We speculate that the positioning of the late pathway genes furthest away from the telomere may mitigate against a 'self-poisoning' scenario in which toxic intermediates accumulate as a result of telomeric gene deletions. Our investigations reveal a striking example of adaptive evolution underpinned by remarkable genome plasticity.

Bacteria-Based Cancer Immunotherapy.

In the past decade, bacteria-based cancer immunotherapy has attracted much attention in the academic circle due to its unique mechanism and abundant applications in triggering the host anti-tumor immunity. One advantage of bacteria lies in their capability in targeting tumors and preferentially colonizing the core area of the tumor. Because bacteria are abundant in pathogen-associated molecular patterns that can effectively activate the immune cells even in the tumor immunosuppressive microenvironment, they are capable of enhancing the specific immune recognition and elimination of tumor cells. More attractively, during the rapid development of synthetic biology, using gene technology to enable bacteria to be an efficient producer of immunotherapeutic agents has led to many creative immunotherapy paradigms. The combination of bacteria and nanomaterials also displays infinite imagination in the multifunctional endowment for cancer immunotherapy. The current progress report summarizes the recent advances in bacteria-based cancer immunotherapy with specific foci on the applications of naive bacteria-, engineered bacteria-, and bacterial components-based cancer immunotherapy, and at the same time discusses future directions in this field of research based on the present developments.

Genome-wide identification of agronomically important genes in outcrossing crops using OutcrossSeq.

Many important crops (e.g., tuber, root, and tree crops) are cross-pollinating. For these crops, no inbred lines are available for genetic study and breeding because they are self-incompatible, clonally propagated, or have a long generation time, making the identification of agronomically important genes difficult, particularly in crops with a complex autopolyploid genome. In this study, we developed a method, OutcrossSeq, for mapping agronomically important loci in outcrossing crops based on whole-genome low-coverage resequencing of a large genetic population, and designed three computation algorithms in OutcrossSeq for different types of outcrossing populations. We applied OutcrossSeq to a tuberous root crop (sweet potato, autopolyploid), a tree crop (walnut tree, highly heterozygous diploid), and hybrid crops (double-cross populations) to generate high-density genotype maps for the outcrossing populations, which enable precise identification of genomic loci underlying important agronomic traits. Candidate causative genes at these loci were detected based on functional clues. Taken together, our results indicate that OutcrossSeq is a robust and powerful method for identifying agronomically important genes in heterozygous species, including polyploids, in a cost-efficient way. The OutcrossSeq software and its instruction manual are available for downloading at www.xhhuanglab.cn/tool/OutcrossSeq.html.

Development of a pH-responsive polymersome inducing endoplasmic reticulum stress and autophagy blockade.

Autophagy is involved in the occurrence and development of tumors. Here, a pH-responsive polymersome codelivering hydroxychloroquine (HCQ) and tunicamycin (Tuni) drugs is developed to simultaneously induce endoplasmic reticulum (ER) stress and autophagic flux blockade for achieving an antitumor effect and inhibiting tumor metastasis. The pH response of poly(ß-amino ester) and HCQ synergistically deacidifies the lysosomes, thereby blocking the fusion of autophagosomes and lysosomes and lastly blocking autophagic flux. The function mechanism of regulating autophagy was systematically investigated on orthotopic luciferase gene-transfected, 4T1 tumor-bearing BALB/c mice through Western blot and immunohistochemistry analyses. The Tuni triggers ER stress to regulate the PERK/Akt signaling pathway to increase the autophagic level. The "autophagic stress" generated by triggering ER stress-induced autophagy and blocking autophagic flux is effective against tumors. The reduced expression of matrix metalloproteinase-2 due to ER stress and reduced focal adhesions turnover due to the blockade of autophagic flux synergistically inhibit tumor metastasis.

Pan-Genome of Wild and Cultivated Soybeans.

Soybean is one of the most important vegetable oil and protein feed crops. To capture the entire genomic diversity, it is needed to construct a complete high-quality pan-genome from diverse soybean accessions. In this study, we performed individual de novo genome assemblies for 26 representative soybeans that were selected from 2,898 deeply sequenced accessions. Using these assembled genomes together with three previously reported genomes, we constructed a graph-based genome and performed pan-genome analysis, which identified numerous genetic variations that cannot be detected by direct mapping of short sequence reads onto a single reference genome. The structural variations from the 2,898 accessions that were genotyped based on the graph-based genome and the RNA sequencing (RNA-seq) data from the representative 26 accessions helped to link genetic variations to candidate genes that are responsible for important traits. This pan-genome resource will promote evolutionary and functional genomics studies in soybean.

A Size-Changeable Collagenase-Modified Nanoscavenger for Increasing Penetration and Retention of Nanomedicine in Deep Tumor Tissue.

The complex tumor microenvironment constitutes a variety of barriers to prevent nanoparticles (NPs) delivery and results in extremely low accumulation of nanomedicines in solid tumors. Here, a newly developed size-changeable collagenase-modified polymer micelle is employed to enhance the penetration and retention of nanomedicine in deep tumor tissue. The TCPPB micelle is first formed by self-assembly of maleimide-terminated poly(ethylene glycol)-block-poly(ß-amino ester) (MAL-PEG-PBAE) and succinic anhydride-modified cisplatin-conjugated poly(ε-caprolactone)-block-poly(ethylene oxide)-triphenylphosphonium (CDDP-PCL-PEO-TPP). Next, Col-TCPPB NPs are prepared through a "click" chemical combination of thiolated collagenase and maleimide groups on TCPPB micelle. Finally, biocompatible chondroitin sulfate (CS) is coated to obtain CS/Col-TCPPB NPs for avoiding collagenase inactivation in blood circulation. In tumor acidic microenvironment, the hydrophobic PBAE segments of the resultant micelles become hydrophilic, leading to a dissociation and subsequent dissolution of partial collagenase-containing components (Col-PEG-PBAE) from NPs. The dissolved Col-PEG-PBAE promotes the digestion of collagen fibers in tumor tissue like a scavenger, which enhances the NPs penetration. Simultaneously, the increased hydrophilicity of residual Col-PEG-PBAE in the micellar matrix causes an expansion of the NPs, resulting in an enhanced intratumoral retention. In tumor cells, the NPs target to release the cisplatin drugs into mitochondria, achieving an excellent anticancer efficacy.

Fenton Reaction-Assisted Photodynamic Therapy for Cancer with Multifunctional Magnetic Nanoparticles.

Tumor hypoxia and the short half-life of reactive oxygen species (ROS) with small diffusion distance have greatly limited the therapeutic effect of photodynamic therapy (PDT). Here, a multifunctional nanoplatform is developed to enhance the PDT effect through increasing the oxygen concentration in tumor cells by the Fenton reaction and reducing the distance between the ROS and the target site by mitochondrial targeting. Fe3O4@Dex-TPP nanoparticles are first prepared by coprecipitation in the presence of triphenylphosphine (TPP)-grafted dextran (Dex-TPP) and Fe2+/Fe3+, which have a magnetic resonance imaging effect. Next, the photosensitizers of protoporphyrin IX (PpIX) and glutathione-responsive mPEG-ss-COOH are grafted on Fe3O4@Dex-TPP to form Fe3O4@Dex/TPP/PpIX/ss-mPEG nanoparticles. After the nanoparticles are internalized, part of Fe3O4 are decomposed into Fe2+/Fe3+ in the acidic lysosome and then Fe2+/Fe3+ diffused into the cytoplasm, and subsequently, Fe2+ reacted with the overproduced H2O2 to produce O2 and •OH. The undecomposed nanoparticles enter the cytoplasm by photoinduced internalization and targeted to the mitochondria, leading to ROS direct generation around the mitochondria. Simultaneously, the produced O2 by the Fenton reaction can serve as a raw material for PDT to continuously exert PDT effect. As a result, the Fenton reaction-assisted PDT can significantly improve the therapeutic efficacy of tumors.

Enhancing the Accumulation of Polymer Micelles by Selectively Dilating Tumor Blood Vessels with NO for Highly Effective Cancer Treatment.

The accumulation of nanoparticles in tumors by the enhanced permeability and retention (EPR) effect is effective and well known. However, how to maximize accumulation is still a bottleneck in the development of nanomedicine. Herein, a tumor vascular-targeted hybrid polymeric micelle, which has a great capacity to selectively augment the EPR effect of nanoparticles by dilating tumor blood vessels via the activity of nitric oxide (NO), is presented. Under neutral conditions, the micelle is stable, with a long blood circulation half-life due to the carboxylated poly(ethylene glycol) (PEG) layer; in mildly acidic tumor tissues, the micelle can selectively target the tumor blood vessels by the exposed cyclic Arg-Gly-Asp peptide (cRGD) peptides, which is realized with a pH-dependent hydrolysis of the monomethoxy PEG layer. Simultaneously, exposed copper ions catalyze the decomposition of endogenous NO donors, which generates NO in situ, leading to vasodilation and increased tumor vascular permeability. As a result, the accumulation of nanoparticles is significantly enhanced, and a high accumulation of doxorubicin in tumors is achieved at 48 h after injection. This high dose of therapeutic agent produces a large inhibition of tumor growth (94%) in cancer treatment, and shows no general toxicity, with 100% of the mice surviving the treatment regimen.

Synthesis and anticancer activity of novel rapamycin C-28 containing triazole moiety compounds.

Rapamycin is an mTOR allosteric inhibitor with multiple functions such as immunosuppressive, anticancer, and lifespan prolonging activities. Its C-43 semi-synthetic derivatives temsirolimus and everolimus have been used as mTOR targeting anticancer drugs in the clinic. Following our previous research on antitumor rapalogs modified on the C-43 position, 13 novel rapamycin triazole hybrids (6a-g, 7a-f) were designed and synthesized on the C-28 position of rapamycin via Huisgen's reaction. Anticancer assays indicated that the targeted derivatives containing phenyl and 4-methylphenyl groups showed an obvious raise in anticancer activity. On the contrary, the compounds with methoxyl, amine, and halogen groups on the benzene ring displayed lower anticancer activity. Compound 6c, as the most active compound, showed a stronger inhibition effect as compared with rapamycin for almost all of the tested cell lines (p < 0.01), except PC-3. Meanwhile, the effect of 6c on inducing apoptosis and cell cycle arrest in A549 cells was more powerful than that of rapamycin. In addition, 6c inhibited the phosphorylation of mTOR and its downstream key kinases 4EBP1 and p70S6K1 in A549 cells, indicating that 6c also effectively inhibits the mTORC1 signaling pathway as rapamycin. On the basis of these findings, 6c may have the potential to be developed as a new mTOR inhibitor against specific cancers.

Induction of mitochondrial apoptosis for cancer therapy via dual-targeted cascade-responsive multifunctional micelles.

Herein, we present a prodrug-loaded multifunctional polymer micelle with hyaluronidase/redox/light multilevel responses and with cell membrane/mitochondrion-dual targeting abilities. This nanocarrier can be internalized by tumor cells via CD44 receptor-mediated targeting. The encapsulated prodrug is released as the carrier is dissociated after the initial degradation of the hyaluronic acid layer by hyaluronidase, followed by the cleavage of the disulfide bonds between hydrophilic and hydrophobic segments in the micelle under the conditions of increased levels of GSH in the cytoplasm. The released prodrug can rapidly target the mitochondria via the TPP function, and convert to the free drug cisplatin through a redox-responsiveness effect. Simultaneously, the membrane permeability of the mitochondria can be improved by the generated reactive oxygen species (ROS) from light irradiation, thus allowing the entry of cisplatin into the mitochondria and causing mitochondrial damage, ultimately leading to mitochondria-mediated apoptosis. Consequently, this nanoformulation shows a highly effective anticancer efficacy in vivo.

Multistage Targeting Strategy Using Magnetic Composite Nanoparticles for Synergism of Photothermal Therapy and Chemotherapy.

Mitochondrial-targeting therapy is an emerging strategy for enhanced cancer treatment. In the present study, a multistage targeting strategy using doxorubicin-loaded magnetic composite nanoparticles is developed for enhanced efficacy of photothermal and chemical therapy. The nanoparticles with a core-shell-SS-shell architecture are composed of a core of Fe3 O4 colloidal nanocrystal clusters, an inner shell of polydopamine (PDA) functionalized with triphenylphosphonium (TPP), and an outer shell of methoxy poly(ethylene glycol) linked to the PDA by disulfide bonds. The magnetic core can increase the accumulation of nanoparticles at the tumor site for the first stage of tumor tissue targeting. After the nanoparticles enter the tumor cells, the second stage of mitochondrial targeting is realized as the mPEG shell is detached from the nanoparticles by redox responsiveness to expose the TPP. Using near-infrared light irradiation at the tumor site, a photothermal effect is generated from the PDA photosensitizer, leading to a dramatic decrease in mitochondrial membrane potential. Simultaneously, the loaded doxorubicin can rapidly enter the mitochondria and subsequently damage the mitochondrial DNA, resulting in cell apoptosis. Thus, the synergism of photothermal therapy and chemotherapy targeting the mitochondria significantly enhances the cancer treatment.