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1.
Adv Mater ; : e2401384, 2024 Mar 24.
Article in English | MEDLINE | ID: mdl-38521987

ABSTRACT

Genome editing has the potential to improve the unsatisfactory therapeutic effect of antitumor immunotherapy. However, the cell plasma membrane prevents the entry of almost all free genome-manipulation agents. Therefore, a system can be spatiotemporally controlled and can instantly open the cellular membrane to allow the entry of genome-editing agents into target cells is needed. Here, inspired by the ability of T cells to deliver cytotoxins to cancer cells by perforation, an ultrasound (US)-controlled perforation system (UPS) is established to enhance the delivery of free genome-manipulating agents. The UPS can perforate the tumor cell membrane while maintaining cell viability via a controllable lipid peroxidation reaction. In vitro, transmembrane-incapable plasmids can enter cells and perform genome editing with the assistance of UPS, achieving an efficiency of up to 90%. In vivo, the UPS is biodegradable, nonimmunogenic, and tumor-targeting, enabling the puncturing of tumor cells under US. With the application of UPS-assisted genome editing, gasdermin-E expression in 4T1 tumor-bearing mice is successfully restored, which leads to pyroptosis-mediated antitumor immunotherapy via low-dose X-ray irradiation. This study provides new insights for designing a sonoporation system for genome editing. Moreover, the results demonstrate that restoring gasdermin expression by genome editing significantly improves the efficacy of radioimmunotherapy.

2.
Adv Sci (Weinh) ; : e2305934, 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38484186

ABSTRACT

The Gasdermin protein is a membrane disruptor that can mediate immunogenic pyroptosis and elicit anti-tumor immune function. However, cancer cells downregulate Gasdermin and develop membrane repair mechanisms to resist pyroptosis. Therefore, an artificial membrane disruptor (AMD) that can directly mediate membrane rupture in pyroptosis-deficient cells and induce antitumor immune responses in a controllable manner will be valuable in preclinical and clinical research. A micron-scale Ce6-based AMD that can directly induce plasma membrane rupture (PMR) in gasdermin-deficient tumor cells is established. Micron-scale AMDs localize Ce6 specifically to the plasma membrane without labeling other organelles. Compared to free Ce6 molecules, the use of AMDs results in a higher degree of specificity for the plasma membrane. Due to this specificity, AMDs mediate fast and irreversible PMR under 660 nm red light. Furthermore, the AMDs are capable of inducing programmed cell death and lytic cell death in a catalytic manner, demonstrating that the amount of Ce6 used by AMDs is only one-fifth of that used by Ce6 alone when inducing 80% of cancer cell death. In vivo, the AMDs show specificity for tumor targeting and penetration, suggesting that light-driven programmed cell death is specific to tumors. AMDs are applied to antitumor therapy in gasdermin-deficient tumors, resulting in efficient tumor elimination with minimal damage to major organs when combined with anti-PD-1 therapy. Tumor regression is correlated with PMR-mediated inflammation and T-cell-based immune responses. This study provides new insights for designing bioinspired membrane disruptors for PMR and mediating anti-tumor immunotherapy. Additionally, AMD is a dependable tool for examining the immunogenicity of PMR both in vitro and in vivo.

3.
Mol Plant ; 17(4): 509-512, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38327053

ABSTRACT

As the master regulators of the ET signaling pathway, EIL transcription factors directly activate the expression of CYP94C1 to inactivate bioactive JA-Ile, thereby attenuating JA-mediated defense during fruit ripening. Knockout of CYP94C1 improves tomato fruit resistance to necrotrophs without compromising fruit quality.


Subject(s)
Isoleucine/analogs & derivatives , Solanum lycopersicum , Solanum lycopersicum/genetics , Fruit/genetics , Fruit/metabolism , Oxylipins/metabolism , Cyclopentanes/metabolism , Gene Expression Regulation, Plant
4.
Adv Mater ; 36(13): e2309839, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38102944

ABSTRACT

A Cytotoxic T lymphocyte-inspired system capable of using ultralow-dose chemical drugs to manipulate cell death is needed to investigate the antitumor immunotherapy. Recent studies reveal pyroptosis promotes antitumor immune function. However, high-dose chemotherapy leads to cytokine release syndrome by pyroptosis. Therefore, pyroptosis-inducing ultralow-dose chemotherapy is potential in preclinical and clinical research, but its efficacy, safety, and the antitumor immune responses are not clear. Here, a near-infrared light controllable killing system (BIK system) is established by which ultralow-dose doxorubicin can be spatiotemporally transported to tumor cells and mediate efficient pyroptosis. This BIK system reduces total drug consumption to less than one-thirtieth the common dose in vitro. Moreover, this BIK system exhibited good tumor targeting and tumor penetration. This system is applied for pyroptosis-induced antitumor therapies, which shows less than ≈25 µg kg-1 doxorubicin is sufficient for tumor regression with negligible injuries to major organs. The antitumor immune function are proven to correlate with the impressive efficacy of pyroptosis-inducing ultralow-dose chemotherapy. This study provides new insights into the design of nanoassisted systems for activating the antitumor immunity by microstimulation; the application of the BIK system suggests that ultralow-dose chemotherapy is sufficient for inducing a robust pyroptosis-mediated antitumor immunity.


Subject(s)
Neoplasms , Pyroptosis , Humans , T-Lymphocytes, Cytotoxic , Neoplasms/drug therapy , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Immunity
5.
Nat Commun ; 14(1): 5456, 2023 09 06.
Article in English | MEDLINE | ID: mdl-37673934

ABSTRACT

Lytic cell death triggers an antitumour immune response. However, cancer cells evade lytic cell death by several mechanisms. Moreover, a prolonged and uncontrolled immune response conversely leads to T-cell exhaustion. Therefore, an oncolytic system capable of eliciting an immune response by killing cancer cells in a controlled manner is needed. Here, we establish a micro-scale cytotoxic T-cell-inspired oncolytic system (TIOs) to precisely lyse cancer cells by NIR-light-controlled lipid peroxidation. Our TIOs present antigen-based cell recognition, tumour-targeting and catalytic cell-lysis ability; thus, the TIOs induce oncolysis in vivo. We apply TIOs to preclinical cancer models, showing anti-tumor activity with negligible side-effects. Tumour regression is correlated with a T-cell based anti-tumour immune response and TIOs also improve responses to anti-PD-1 therapy or STING activation. Our study provides insights to design oncolytic systems for antitumour immunity. Moreover, activation of STING can reverse T-cell exhaustion in oncolysis.


Subject(s)
Cell Communication , T-Lymphocytes, Cytotoxic , Lipid Peroxidation , Catalysis , Cell Death
6.
Appl Microbiol Biotechnol ; 107(12): 3955-3966, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37166480

ABSTRACT

Fusion tag technology is an important tool for rapid separation, purification, and characterization of proteins. Combined with monoclonal antibodies, tag epitope systems can be rapidly adapted to many assay systems. A monoclonal antibody that reacts with the matrix protein of the rabies virus CVS-11 strain was reported. The epitope (termed M) targeted by this antibody contains only six amino acids. We examine whether this specific sequence epitope can be applied as a protein tag. We show ectopic expression of M-tagged proteins has little impact on cell viability or major signaling pathways. The M tag system can be used for western blotting, immunoprecipitation, immunofluorescence staining, and flow cytometry assays. The results indicate the specificity, sensitivity, and versatility of this novel epitope tag system are comparable to the widely used FLAG tag system, providing researchers with an additional tool for molecular analysis. KEY POINTS: • A short peptide (Pro Pro Tyr Asp Asp Asp) can be applied as a new tag. • The new epitope-tagging fusion system has no effect on the main cellular signaling pathway. • The epitope-tagging fusion system can be widely used for western blotting, immunoprecipitation, immunofluorescence, flow cytometry, etc.


Subject(s)
Rabies virus , Epitopes , Rabies virus/genetics , Peptides/metabolism , Antibodies, Monoclonal , Blotting, Western
7.
Front Immunol ; 13: 861723, 2022.
Article in English | MEDLINE | ID: mdl-35603146

ABSTRACT

Background: Drug-drug interactions (DDIs) pose new challenges beyond traditional pharmacodynamics in the context of optimizing the treatment options with immune checkpoint inhibitors (ICIs). To alleviate cancer-related pain, analgesics are of absolute vital importance as chronic medications used by cancer patients. However, the possible outcome of ICI treatment concomitant with analgesics remains unclear. Methods: Original articles describing the possible influence of analgesics use on ICI treatment published before December 1, 2021 were retrieved from PubMed, Embase, and the Cochrane Library. Odds ratio (OR) with 95% confidence interval (CI) for objective response rate (ORR), hazard ratio (HR) with 95% CI for progression-free survival (PFS), and overall survival (OS) were calculated using the random-effects or fixed-effects model, and heterogeneity was assessed using the χ2-based Q-test. Publication bias was examined by funnel plot analysis. Results: A total of 11 studies involving 4,404 patients were included. The pooled OR showed that opioid use decreased the response of opioid users to ICIs compared to non-opioid users (OR = 0.49, 95% CI = 0.37-0.65, p < 0.001). Compared to patients who did not receive opioids, opioid users had an increased risk of progression and mortality (HR = 1.61, 95% CI = 1.37-1.89, p < 0.001; HR = 1.67, 95% CI =1.30-2.14, p < 0.001, respectively). Furthermore, the concomitant use of non-steroidal anti-inflammatory drugs (NSAIDs) was not significantly associated with differences in ORR, PFS, and OS in patients treated with ICIs (OR = 1.40, 95% CI = 0.84-2.32, p = 0.190; HR = 0.90, 95% CI = 0.77-1.06, p = 0.186; HR = 0.90, 95% CI = 0.71-1.14, p = 0.384, respectively). Conclusion: The concomitant use of opioids during ICI treatment has an adverse effect on patient prognosis, while the use of NSAIDs is not significantly associated with the prognosis in patients treated with ICIs.


Subject(s)
Analgesics, Opioid , Immune Checkpoint Inhibitors , Analgesics , Analgesics, Opioid/adverse effects , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Humans , Immune Checkpoint Inhibitors/adverse effects , Prognosis
8.
Immunotherapy ; 2022 Mar 09.
Article in English | MEDLINE | ID: mdl-35259921

ABSTRACT

Aim: To compare the efficacy and safety of first-line chemotherapy (Chemo) plus immune checkpoint inhibitors (ICIs) or bevacizumab (Bev) in advanced non-squamous non-small-cell lung cancer without EGFR mutations or ALK fusions. Methods: A network meta-analysis was conducted to synthesize relative treatment outcomes. Results: Chemo + ICIs is superior to Chemo + Bev in both overall survival (hazard ratio: 0.92; 95% CI: 0.88-0.96) and progression-free survival (hazard ratio: 0.93; 95% CI: 0.90-0.97), with comparable severe adverse events. However, for patients with liver metastasis, Chemo + Bev has a 59.8% probability of providing better overall survival benefit. For specific regimens, pembrolizumab + Chemo showed an absolute advantage over other regimens. Conclusion: First-line Chemo + ICIs is superior to Chemo + Bev in advanced non-squamous non-small-cell lung cancer except for patients with liver metastasis.


Chemotherapy plus immune checkpoint inhibitors and chemotherapy plus bevacizumab were both superior to traditional chemotherapy and were recommended as the first-line treatment for advanced non-squamous non-small-cell lung cancer patients without EGFR mutations or ALK fusions. However, the efficacy and safety of these two treatment models have not been comprehensively discussed head-to-head in clinical trials. Therefore, a network meta-analysis was performed to compare efficacy between these two treatment models, especially according to different clinical characteristics, to guide decision making in clinical practice.

9.
Front Immunol ; 13: 1042072, 2022.
Article in English | MEDLINE | ID: mdl-36591290

ABSTRACT

Objective: Besides breast and gastric cancer, HER2 amplification/mutation are also found in lung adenocarcinoma (LUAD). However, the correlation between HER2 variations and the phenotype of immunogenicity and tumor immune microenvironment (TIME) in LUAD compared with breast and gastric cancer has yet to be fully elucidated. Methods: We integrated public databases (discovery set) and internal data (validated set) of 288 patients representing three distinct HER2-altered tumors. Genomic data were used to identify somatic mutations, copy number variations, and calculate tumor mutational burden (TMB) and microsatellite instability score. RNA sequencing was conducted to estimate immune gene signatures and contents of tumor-infiltrating immune cell populations. Finally, IHC was used to determine PD-L1 expression and the tumoral-infiltration of immune cells in 50 HER2-variant tumor specimens with no prior therapeutic regimens. Results: Compared with HER2-amplified breast and gastric cancers, patients with HER2-amplified LUAD showed higher immunogenicity, mainly manifested in immune checkpoints expression and tissue/blood TMB. Additionally, HER2-amplified LUAD exhibited an inflamed TIME with remarkably increased genes encoding HLAs, T-cell activity and immune cell-type, and accompanied with tumor-infiltrating lymphocytes. In LUAD, patients with HER2 amplification possessed higher tissue TMB than HER2 mutation, whereas no difference was observed in PD-L1 expression. HER2 amplification (primary) was associated with significantly higher PD-L1 expression and TMB than acquired HER2 amplification after resistance to EGFR-TKIs. Conclusion: Patients with HER2-amplified LUAD have better immunogenicity and/or an inflamed TIME among HER2-aberrant tumors. Our study may provide clues for establishing the benefits and uses of ICIs for patients with this disease.


Subject(s)
Adenocarcinoma of Lung , Lung Neoplasms , Receptor, ErbB-2 , Stomach Neoplasms , Tumor Microenvironment , Humans , Adenocarcinoma of Lung/genetics , Adenocarcinoma of Lung/immunology , Adenocarcinoma of Lung/pathology , B7-H1 Antigen/metabolism , Biomarkers, Tumor/genetics , Biomarkers, Tumor/immunology , DNA Copy Number Variations , Lung Neoplasms/genetics , Lung Neoplasms/immunology , Lung Neoplasms/pathology , Tumor Microenvironment/genetics , Tumor Microenvironment/immunology , Receptor, ErbB-2/genetics , Receptor, ErbB-2/immunology
10.
Cancer Med ; 10(24): 9139-9155, 2021 12.
Article in English | MEDLINE | ID: mdl-34747149

ABSTRACT

BACKGROUND: Immune-based combination therapies have revolutionized the first-line treatment for advanced non-small cell lung cancer (NSCLC). However, for the efficacy and safety, the best treatment option is still uncertain. METHODS: We conducted a Bayesian network meta-analysis of randomized controlled trials (RCTs) to evaluate first-line immune-based combination therapies for advanced NSCLC. RESULTS: Fourteen trials involving 8467 patients were included. For the programmed cell death-ligand 1 (PD-L1) expression non-selective patients, there were no significant differences among all the treatment modes for overall survival (OS), but the ranking profiles indicated that Immunotherapy + Immunotherapy + Chemotherapy (IO + IO + Chemo) was most likely to be the best mode (probability = 68%). Immunotherapy + Immunotherapy + Anti-angiogenic therapy + Chemotherapy (IO + Anti-angio + Chemo) was significantly better than most other treatment modes for progression-free survival (PFS) with better objective response rate (ORR) and more obvious grade ≥3 treatment-related adverse events (TRAEs). In PD-L1-high cohort, IO + Anti-angio + Chemo seemed to be the best mode for OS, PFS, and ORR according to the ranking profiles. In PD-L1-intermediate and PD-L1-negative cohort, IO + IO + Chemo was inclined to be ranked first for prolonging OS (probability = 78%; 37%) and IO + Anti-angio + Chemo was most likely to provide best PFS (probability = 96%; 100%). CONCLUSION: IO + IO + Chemo has great potential to improve the OS regardless of histology type, especially in PD-L1-intermediate and PD-L1-negative cohort. IO + Anti-angio + Chemo shows great superiority in improving the short-term survival accompanied by increasing grade ≥3 TRAEs.


Subject(s)
Carcinoma, Non-Small-Cell Lung/drug therapy , Immunotherapy/methods , Lung Neoplasms/drug therapy , Bayes Theorem , Carcinoma, Non-Small-Cell Lung/pathology , Humans , Lung Neoplasms/pathology , Network Meta-Analysis
11.
Front Oncol ; 11: 698199, 2021.
Article in English | MEDLINE | ID: mdl-34589422

ABSTRACT

BACKGROUND: Nivolumab + ipilimumab + two cycles chemotherapy (N-I + chemo, intensive immunotherapy but chemo-light) and pembrolizumab + chemotherapy (Pem + chemo) were both recommended as first-line treatment for metastatic non-small cell lung carcinoma (NSCLC) patients. We conducted this indirect comparison to compare the efficacy of and safety between these two treatments for providing reference for decision making. METHODS: Relevant databases were searched for eligible trials. A well-accepted adjusted indirect treatment comparison (ITC) approach was selected to pool efficacy results and safety outcomes. Subgroup analyses were stratified according to PD-L1 expression and clinical characteristics. RESULTS: Four eligible randomized trials (CheckMate9LA, KEYNOTE-021G, KEYNOTE 189, KEYNOTE 407) involving 2017 patients were available to analyze. The ITC results suggested that N-I + chemo is comparable to Pem + chemo in OS (HR 1.03, 95% CI 0.82-1.30) and ORR (RR 0.81, 95% CI 0.62-1.06), but tended to yield inferior PFS (HR 1.28, 95% CI 1.04-1.59) than did Pem + chemo. As for safety profiles, N-I + chemo showed no significant difference relative to Pem + chemo in any grade adverse events: (RR 1.03, 95% CI 0.99-1.10), but demonstrated reduced toxicity in chemo-related adverse events, such as anemia (RR 0.63, 95% CI 0.49-0.81), neutropenia (RR0.51, 95% CI 0.33-0.79), and thrombocytopenia (RR 0.38, 95% CI 0.21-0.69). CONCLUSIONS: N-I + chemo is a promising treatment option for providing comparable OS related to Pem + chemo. However, for never smoker female patients, Pem + chemo is preferable to choose for demonstrating favorable OS benefit than N-I + chemo.

12.
Curr Biol ; 30(24): 4826-4836.e7, 2020 12 21.
Article in English | MEDLINE | ID: mdl-33035482

ABSTRACT

Recent studies have reported that aphids facilitate their colonization of host plants by secreting salivary proteins into host tissues during their initial probing and feeding. Some of these salivary proteins elicit plant defenses, but the molecular and biochemical mechanisms that underlie the activation of phloem-localized resistance remain poorly understood. The aphid Myzus persicae, which is a generalized phloem-sucking pest, encompasses a number of lineages that are associated with and adapted to specific host plant species. The current study found that a cysteine protease Cathepsin B3 (CathB3), and the associated gene CathB3, was upregulated in the salivary glands and saliva of aphids from a non-tobacco-adapted (NTA) aphid lineage, when compared to those of a tobacco-adapted lineage. Furthermore, the knockdown of CathB3 improved the performance of NTA lineages on tobacco, and the propeptide domain of CathB3 was found to bind to tobacco cytoplasmic kinase ENHANCED DISEASE RESISTANCE 1-like (EDR1-like), which triggers the accumulation of reactive oxygen species in tobacco phloem, thereby suppressing both phloem feeding and colonization by NTA lineages. These findings reveal a novel function for a cathepsin-type protease in aphid saliva that elicits effective host plant defenses and warranted the theory of host specialization for generalist aphids.


Subject(s)
Aphids/physiology , Cathepsin B/metabolism , Insect Proteins/metabolism , Nicotiana/parasitology , Salivary Proteins and Peptides/metabolism , Adaptation, Physiological , Animals , Disease Resistance , Feeding Behavior , Gene Knockdown Techniques , Host Specificity/physiology , Host-Parasite Interactions/physiology , Insect Proteins/genetics , MAP Kinase Kinase Kinases/metabolism , Phloem/metabolism , Phloem/parasitology , Plant Proteins/metabolism , Plants, Genetically Modified , Protein Binding/physiology , Protein Domains/physiology , Reactive Oxygen Species/metabolism , Saliva/enzymology , Salivary Glands/enzymology , Up-Regulation
13.
Plant Cell Environ ; 43(9): 2311-2322, 2020 09.
Article in English | MEDLINE | ID: mdl-32596816

ABSTRACT

Aphids often carry facultative symbionts to achieve diverse advantages. Serratia symbiotica, one of facultative endosymbionts, increases aphid tolerance to heat. However, whether it benefits aphid colonization on host plants is yet to be determined. In the current study, we found that Acyrthosiphon pisum harbouring S. symbiotica had longer feeding duration on Medicago truncatula than Serratia-free aphids. Contrastingly, Serratia-free aphids triggered higher accumulation of reactive oxygen species (ROS), jasmonic acid and salicylic acid responsive genes and cytosolic Ca2+ elevations than Serratia-infected aphids. Transcriptomic analysis of salivary glands indicated that a histidine-rich Ca2+ -binding protein-like gene (ApHRC) was expressed more highly in the salivary gland of Serratia-infected aphids than that of Serratia-free aphids. Once ApHRC was silenced, Serratia-infected aphids also displayed shorter phloem-feeding duration and caused Ca2+ elevation and ROS accumulation in plants. Our results suggest that ApHRC, a potential effector up-regulated by S. symbiotica in the salivary glands, impairs plant defence response by suppressing Ca2+ elevation and ROS accumulation, allowing colonization of aphids. This study has provided an insight into how facultative symbionts facilitate aphid colonization and adaptation to host plants.


Subject(s)
Aphids/physiology , Medicago truncatula/physiology , Salivary Glands/physiology , Serratia/physiology , Animals , Aphids/genetics , Aphids/microbiology , Calcium/metabolism , China , Gene Expression , Insect Proteins/genetics , Plants, Genetically Modified , Reactive Oxygen Species/metabolism , Symbiosis
14.
Nature ; 579(7799): 421-426, 2020 03.
Article in English | MEDLINE | ID: mdl-32188939

ABSTRACT

Bioorthogonal chemistry capable of operating in live animals is needed to investigate biological processes such as cell death and immunity. Recent studies have identified a gasdermin family of pore-forming proteins that executes inflammasome-dependent and -independent pyroptosis1-5. Pyroptosis is proinflammatory, but its effect on antitumour immunity is unknown. Here we establish a bioorthogonal chemical system, in which a cancer-imaging probe phenylalanine trifluoroborate (Phe-BF3) that can enter cells desilylates and 'cleaves' a designed linker that contains a silyl ether. This system enabled the controlled release of a drug from an antibody-drug conjugate in mice. When combined with nanoparticle-mediated delivery, desilylation catalysed by Phe-BF3 could release a client protein-including an active gasdermin-from a nanoparticle conjugate, selectively into tumour cells in mice. We applied this bioorthogonal system to gasdermin, which revealed that pyroptosis of less than 15% of tumour cells was sufficient to clear the entire 4T1 mammary tumour graft. The tumour regression was absent in immune-deficient mice or upon T cell depletion, and was correlated with augmented antitumour immune responses. The injection of a reduced, ineffective dose of nanoparticle-conjugated gasdermin along with Phe-BF3 sensitized 4T1 tumours to anti-PD1 therapy. Our bioorthogonal system based on Phe-BF3 desilylation is therefore a powerful tool for chemical biology; our application of this system suggests that pyroptosis-induced inflammation triggers robust antitumour immunity and can synergize with checkpoint blockade.


Subject(s)
Delayed-Action Preparations/administration & dosage , Mammary Neoplasms, Experimental/immunology , Pyroptosis/immunology , Animals , Coumarins/administration & dosage , Coumarins/chemistry , Coumarins/metabolism , Coumarins/pharmacokinetics , Delayed-Action Preparations/chemistry , Delayed-Action Preparations/metabolism , Delayed-Action Preparations/pharmacokinetics , Female , Green Fluorescent Proteins/administration & dosage , Green Fluorescent Proteins/chemistry , Green Fluorescent Proteins/metabolism , Green Fluorescent Proteins/pharmacokinetics , HeLa Cells , Humans , Immunoconjugates/administration & dosage , Immunoconjugates/chemistry , Immunoconjugates/metabolism , Immunoconjugates/pharmacokinetics , Inflammasomes/immunology , Inflammation/immunology , Inflammation/metabolism , Inflammation/pathology , Mammary Neoplasms, Experimental/metabolism , Mammary Neoplasms, Experimental/pathology , Mice , Mice, Inbred BALB C , Oligopeptides/administration & dosage , Oligopeptides/chemistry , Oligopeptides/metabolism , Oligopeptides/pharmacokinetics , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Proteins/administration & dosage , Proteins/chemistry , Proteins/metabolism , Proteins/pharmacokinetics , Silanes/administration & dosage , Silanes/chemistry , Silanes/metabolism , Silanes/pharmacokinetics , T-Lymphocytes/immunology , Trastuzumab/administration & dosage , Trastuzumab/chemistry , Trastuzumab/metabolism , Trastuzumab/pharmacokinetics , Xenograft Model Antitumor Assays
15.
J Org Chem ; 83(13): 6907-6923, 2018 07 06.
Article in English | MEDLINE | ID: mdl-29508620

ABSTRACT

The asymmetric total synthesis of lancifodilactone G acetate was accomplished in 28 steps. The key steps in this synthesis include (i) an asymmetric Diels-Alder reaction for formation of the scaffold of the BC ring; (ii) an intramolecular ring-closing metathesis reaction for the formation of the trisubstituted cyclooctene using a Hoveyda-Grubbs II catalyst; (iii) an intramolecular Pauson-Khand reaction for construction of the sterically congested F ring; (iv) sequential cross-metathesis, hydrogenation, and lactonization reactions for installation of the anomerically stabilized bis-spiro ketal fragment of lancifodilactone G; and (v) a Dieckmann-type condensation reaction for installation of the A ring. The strategy and chemistry developed for the total synthesis will be useful in the synthesis of other natural products and complex molecules.

16.
J Exp Bot ; 67(3): 681-93, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26546578

ABSTRACT

The activation of the abscisic acid (ABA) signaling pathway reduces water loss from plants challenged by drought stress. The effect of drought-induced ABA signaling on the defense and nutrition allocation of plants is largely unknown. We postulated that these changes can affect herbivorous insects. We studied the effects of drought on different feeding stages of pea aphids in the wild-type A17 of Medicago truncatula and ABA signaling pathway mutant sta-1. We examined the impact of drought on plant water status, induced plant defense signaling via the abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA) pathways, and on the host nutritional quality in terms of leaf free amino acid content. During the penetration phase of aphid feeding, drought decreased epidermis/mesophyll resistance but increased mesophyll/phloem resistance of A17 but not sta-1 plants. Quantification of transcripts associated with ABA, JA and SA signaling indicated that the drought-induced up-regulation of ABA signaling decreased the SA-dependent defense but increased the JA-dependent defense in A17 plants. During the phloem-feeding phase, drought had little effect on the amino acid concentrations and the associated aphid phloem-feeding parameters in both plant genotypes. In the xylem absorption stage, drought decreased xylem absorption time of aphids in both genotypes because of decreased water potential. Nevertheless, the activation of the ABA signaling pathway increased water-use efficiency of A17 plants by decreasing the stomatal aperture and transpiration rate. In contrast, the water potential of sta-1 plants (unable to close stomata) was too low to support xylem absorption activity of aphids; the aphids on sta-1 plants had the highest hemolymph osmolarity and lowest abundance under drought conditions. Taken together this study illustrates the significance of cross-talk between biotic-abiotic signaling pathways in plant-aphid interaction, and reveals the mechanisms leading to alter aphid fecundity in water stresses plants.


Subject(s)
Abscisic Acid/metabolism , Aphids/physiology , Droughts , Osmoregulation , Signal Transduction , Stress, Physiological , Up-Regulation , Xylem/physiology , Absorption, Physiological/drug effects , Amino Acids/metabolism , Animals , Feeding Behavior/drug effects , Gases/metabolism , Gene Expression Regulation, Plant/drug effects , Hemolymph/drug effects , Hemolymph/metabolism , Medicago truncatula/drug effects , Medicago truncatula/genetics , Medicago truncatula/parasitology , Medicago truncatula/physiology , Models, Biological , Nitrogen/metabolism , Osmolar Concentration , Osmoregulation/drug effects , Phloem/drug effects , Phloem/metabolism , Plant Growth Regulators/pharmacology , Salicylic Acid/metabolism , Signal Transduction/drug effects , Stress, Physiological/drug effects , Up-Regulation/drug effects , Water/metabolism , Xylem/drug effects
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