Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins ...Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins and other factors involved in various biological processes,includingβ-lactamase and antibiotic-resistance genes.This study aimed to reveal the transmission mechanism of OMV-mediated drug resistance of Klebsiella(K.)pneumoniae.Methods We selected CR-KP producing K.pneumoniae carbapenemase-2(KPC-2)to study whether they can transfer resistance genes through OMVs.The OMVs of CR-KP were obtained by ultracentrifugation,and incubated with carbapenem-sensitive K.pneumoniae for 4 h.Finally,the carbapenem-sensitive K.pneumoniae was tested for the presence of bla_(KPC-2)resistance gene and its sensitivity to carbapenem antibiotics.Results The existence of OMVs was observed by the electron microscopy.The extracted OMVs had bla_(KPC-2)resistance gene.After incubation with OMVs,bla_(KPC-2)resistance gene was detected in sensitive K.pneumoniae,and it became resistant to imipenem and meropenem.Conclusion This study demonstrated that OMVs isolated from KPC-2-producing CR-KP could deliver bla_(KPC-2)to sensitive K.pneumoniae,allowing the bacteria to produce carbapenemase,which may provide a novel target for innovative therapies in combination with conventional antibiotics for treating carbapenem-resistant Enterobacteriaceae.展开更多
Vibrio splendidus is an important opportunistic pathogen ubiquitously present in the marine environment,exhibiting virulence to a variety of cultured animals.The extracellular products secreted by V.splendidus are cru...Vibrio splendidus is an important opportunistic pathogen ubiquitously present in the marine environment,exhibiting virulence to a variety of cultured animals.The extracellular products secreted by V.splendidus are crucial to bacterial survival and virulence.In this study,the secretion of outer membrane vesicles(OMVs)by V.splendidus was determined,purified,and morphologically characterized.The protein composition of OMVs was analyzed by proteomic analysis.The results showed that approximately 120 proteins were contained in these OMVs,including outer membrane proteins,flagellins,ABC transporters,protease,and iron regulation proteins,etc.,which were involved in bacterial motility,formation of biofilms and the cell membrane components,and cellular localization based on their structural molecule activity,passive transmembrane transporter activity,channel activity,neurotransmitter receptor activity,extracellular ligand-gated ion channel activity,glutamate receptor activity,ligand-gated ion channel activity,and transmembrane signaling receptor activity.To explore the biological functions of OMVs in V.splendidus,the effects of OMVs on the bacterial adaption to iron limitation,antibiotic,and the coelomic fluid of the Apostichopus japonicus were confirmed.This study is the first time to show that V.splendidus secretes OMVs,and OMVs carry functional proteins that enhance bacterial survival under various stresses.展开更多
Tumor treatment remains a significant medical challenge,with many traditional therapies causing notable side effects.Recent research has led to the development of immunotherapy,which offers numerous advantages.Bacteri...Tumor treatment remains a significant medical challenge,with many traditional therapies causing notable side effects.Recent research has led to the development of immunotherapy,which offers numerous advantages.Bacteria inherently possess motility,allowing them to preferentially colonize tumors and modulate the tumor immune microenvironment,thus influencing the efficacy of immunotherapy.Bacterial outer membrane vesicles(OMVs)secreted by gram-negative bacteria are nanoscale lipid bilayer structures rich in bacterial antigens,pathogen-associated molecular patterns(PAMPs),various proteins,and vesicle structures.These features allow OMVs to stimulate immune system activation,generate immune responses,and serve as efficient drug delivery vehicles.This dual capability enhances the effectiveness of immunotherapy combined with chemotherapy or phototherapy,thereby improving anticancer drug efficacy.Current research has concentrated on engineering OMVs to enhance production yield,minimize cytotoxicity,and improve the safety and efficacy of treatments.Consequently,OMVs hold great promise for applications in tumor immunotherapy,tumor vaccine development,and drug delivery.This article provides an overview of the structural composition and immune mechanisms of OMVs,details various OMVs modification strategies,and reviews the progress in using OMVs for tumor treatment and their anti-tumor mechanisms.Additionally,it discusses the challenges faced in translating OMV-based anti-tumor therapies into clinical practice,aiming to provide a comprehensive understanding of OMVs'potential for in-depth research and clinical application.展开更多
In this study, liposomes were used to decorate bacterial outer membrane vesicles(OMVs), and decorated OMVs were evaluated in vitro. The OMVs of Pseudomonas aeruginosa were extracted by pressure-induced ammonium sulfat...In this study, liposomes were used to decorate bacterial outer membrane vesicles(OMVs), and decorated OMVs were evaluated in vitro. The OMVs of Pseudomonas aeruginosa were extracted by pressure-induced ammonium sulfate precipitation,and their particle size, distribution, zeta potential, protein content and stability were determined. Several types of liposomes were prepared by thin film dispersion method, and the OMVs were decorated by vortexing, sonication and extrusion, respectively. The interaction between liposome and OMV was studied with fluorescence resonance energy transfer(FRET) method. The results showed that the OMVs were spherical in shape and negatively charged. The vortexing method exerted little effect on the particle size and distribution of the decorated OMVs. The sonication process reduced the particle size and distribution of OMVs. FRET experiment indicated that the OMVs were decorated through membrane fusion. The above-mentioned results indicated that liposomes could successfully decorate OMVs, and decorated OMVs certainly widened their applications.展开更多
1 Introduction Outer-membrane vesicles (OMVs) are nanoscale,bilayered particles shed by Gram-negative bacteria [1].Enriched in lipopolysaccharides (LPS),outer-membrane proteins,and periplasmic cargos (Figure 1),OMVs a...1 Introduction Outer-membrane vesicles (OMVs) are nanoscale,bilayered particles shed by Gram-negative bacteria [1].Enriched in lipopolysaccharides (LPS),outer-membrane proteins,and periplasmic cargos (Figure 1),OMVs are central to bacterial communication and host interaction,and they naturally traffic proteins,nucleic acids,and small molecules across biological barriers [2].These same traits,intrinsic immunogenicity,colloidal stability in complex fluids,and efficient cell entry,have positioned OMVs as attractive chassis for vaccines and drug delivery [3–5].Yet native vesicles are constrained by non-specific biodistribution,batch heterogeneity,reactogenic LPS,and limited control over cargo loading and release [6,7].These challenges necessitate the development of strategies to enhance their functionality and broaden their applications.展开更多
Bacterial outer membrane vesicles(OMVs)are potent immuno-stimulating agents and have the potentials to be bioengineered as platforms for antitumor nanomedicine.In this study,OMVs are demonstrated as promising antitumo...Bacterial outer membrane vesicles(OMVs)are potent immuno-stimulating agents and have the potentials to be bioengineered as platforms for antitumor nanomedicine.In this study,OMVs are demonstrated as promising antitumor therapeutics.OMVs can lead to beneficial M2-to-M1 polarization of macrophages and induce pyroptosis to enhance antitumor immunity,but the therapeutic window of OMVs is narrow for its toxicity.We propose a bioengineering strategy to enhance the tumor-targeting ability of OMVs by macrophage-mediated delivery and improve the antitumor efficacy by co-loading of photosensitizer chlorin e6(Ce6)and chemotherapeutic drug doxorubicin(DOX)into OMVs as a therapeutic platform.We demonstrate that systemic injection of the DOX/Ce6-OMVs@M therapeutic platform,providing combinational photodynamic/chemo-/immunotherapy,eradicates triple-negative breast tumors in mice without side effects.Importantly,this strategy also effectively prevents tumor metastasis to the lung.This OMVs-based strategy with bioengineering may serve as a powerful therapeutic platform for a synergic antitumor therapy.展开更多
Nanocarriers with intrinsic immune adjuvant properties can activate the innate immune system while delivering tumor antigen,thus efficiently facilitating antitumor adaptive immunity.Bacteria-derived outer membrane ves...Nanocarriers with intrinsic immune adjuvant properties can activate the innate immune system while delivering tumor antigen,thus efficiently facilitating antitumor adaptive immunity.Bacteria-derived outer membrane vesicles(OMVs)are an excellent candidate due to their abundance of pathogen associated molecular patterns.However,during the uptake of OMVs by dendritic cells(DCs),the interaction between lipopolysaccharide and toll-like receptor 4 induces rapid DC maturation and uptake blockage,a phenomenon we refer to as“maturation-induced uptake obstruction"(MUO).Herein we decorated OMV with the DC-targeting aDEC205 antibody(OMV-DEC),which endowed the nanovaccine with an uptake mechanism termed as 4<not restricted to maturation via antibody modifying”(Normandy),thereby overcoming the MUO phenomenon.We also proved the applicability of this nanovaccine in identifying the human tumor neoantigens through rapid antigen display.In summary,this engineered OMV represents a powerful nanocarrier for personalized cancer vaccines,and this antibody modification strategy provides a reference to remodel the DC uptake pattern in nanocarrier design.展开更多
Bacterial outer membrane vesicles(OMVs)are potent immunostimulants of regulating the tumor microenvironment(TME)for immunotherapy,and can be used to deliver drugs.However,the severe systemic inflammatory response trig...Bacterial outer membrane vesicles(OMVs)are potent immunostimulants of regulating the tumor microenvironment(TME)for immunotherapy,and can be used to deliver drugs.However,the severe systemic inflammatory response triggered by OMVs upon intravenous(i.v.)injection has limited their application.Here,we developed a safe and effective strategy by conjugating doxorubicin-loaded serum albumin(SA-DOX,AD)onto the surface of OMVs using a matrix metalloproteinase(MMP)-cleavable peptide linker(cL).This approach enabled the dynamic shielding of OMVs to reduce the systemic side effects while simultaneously enhancing the anti-tumor effects through chemo-immunotherapy.Specifically,the resulting OMV-cL-AD formulation exhibited significantly enhanced accumulation at the tumor site after i.v.administration,facilitated by the SA decoration on the OMVs surface.Subsequently,the shield on the OMV-cL-AD was cleaved by the over-expressed MMP in the TME,leading to the release of both OMVs and AD.This process provided OMV-induced immunotherapy and DOX-induced chemotherapy,resulting in synergistic tumor inhibition.In conclusion,our work demonstrated the potential of OMV-cL-AD as an effective immunochemotherapy strategy that can prolong the survival time of mice without inducing side effects.展开更多
Bacterial outer membrane vesicles(OMVs)have shown great potential in cancer immunotherapy.The isolation of OMVs from complex media with high purity and high bioactivity is the prerequisite of therapeutic applications,...Bacterial outer membrane vesicles(OMVs)have shown great potential in cancer immunotherapy.The isolation of OMVs from complex media with high purity and high bioactivity is the prerequisite of therapeutic applications,which remains highly challenging.Herein,we report a smart DNA hydrogel for the efficient isolation of OMVs from bacterial culture medium,which is further applied for localized cancer immunotherapy.The DNA hydrogel is constructed through the cross-linking of two ultralong DNA chains generated via rolling circle amplification(RCA).One chain contains polyvalent GN6 aptamer for the specific capture of OMVs,and the other contains polyvalent programmed death-1(PD-1)aptamer for the blocking of PD-1 immune checkpoint on the surface of T lymphocytes.The OMVs capsulated by DNA hydrogel maintain high immunostimulatory bioactivity.In the mouse model of melanoma,this OMVs-containing DNA hydrogel shows a remarkable tumor inhibition rate of∼95%.This smart DNA hydrogel represents a promising biomedical platform for the efficient isolation of bacterial-derived OMVs,and provides a powerful strategy for cancer immunotherapy.展开更多
Bacterial outer membrane vesicles(OMVs)are diminutive vesicles naturally released by Gram-negative bacteria.These vesicles possess distinctive characteristics that attract attention for their potential use in drug adm...Bacterial outer membrane vesicles(OMVs)are diminutive vesicles naturally released by Gram-negative bacteria.These vesicles possess distinctive characteristics that attract attention for their potential use in drug administration and immunotherapy in cancer treatment.Therapeutic medicines may be delivered via OMVs directly to the tumor sites,thereby minimizing exposure to healthy cells and lowering the risk of systemic toxicity.Furthermore,the activation of the immune system by OMVs has been demonstrated to facilitate the recognition and elimination of cancer cells,which makes them a desirable tool for immunotherapy.They can also be genetically modified to carry specific antigens,immunomodulatory compounds,and small interfering RNAs,enhancing the immune response to cancerous cells and silencing genes associated with disease progression.Combining OMVs with other cancer treatments like chemotherapy and radiation has shown promising synergistic effects.This review highlights the crucial role of bacterial OMVs in cancer,emphasizing their potential as vectors for novel cancer targeted therapies.As researchers delve deeper into the complexities of these vesicles and their interactions with tumors,there is a growing sense of optimism that this avenue of study will bring positive outcomes and renewed hope to cancer patients in the foreseeable future.展开更多
Noncoding small RNAs(sRNAs)packaged in bacterial outer membrane vesicles(OMVs)function as novel mediators of interspecies communication.While the role of bacterial sRNAs in enhancing virulence is well established,the ...Noncoding small RNAs(sRNAs)packaged in bacterial outer membrane vesicles(OMVs)function as novel mediators of interspecies communication.While the role of bacterial sRNAs in enhancing virulence is well established,the role of sRNAs in the interaction between OMVs from phytopathogenic bacteria and their host plants remains unclear.In this study,we employ RNA sequencing to characterize differentially pack-aged sRNAs in OMVs of the phytopathogen Xanthomonas oryzae pv.oryzicola(Xoc).Our candidate sRNA(Xosr001)was abundant in OMVs and involved in the regulation of OsJMT1 to impair host stomatal immu-nity.Xoc loads Xosr001 into OMVs,which are specifically ttransferred into the mechanical tissues of rice leaves.Xosr001 suppresses OsJMT1 transcript accumulation in vivo,leading to a reduction in MeJA accu-mulation in rice leaves.Furthermore,the application of synthesized Xosr001 sRNA to the leaves of OsJMT1-HA-OE transgenic line results in the suppression of OsJMT1 expression by Xosr001.Notably,the OsJMT1-HA-OE transgenic line exhibited attenuated stomatal immunity and disease susceptibility upon infection with DXosr001 compared to Xoc.These results suggest that Xosr001 packaged in Xoc OMVs functions to suppress stomatal immunity in rice.展开更多
Outer membrane vesicles(OMVs)are spherical particles shed from the outer membrane of Gram-negative bacteria,which contain the typical components present in the outer membrane,although enrichment of specific molecules ...Outer membrane vesicles(OMVs)are spherical particles shed from the outer membrane of Gram-negative bacteria,which contain the typical components present in the outer membrane,although enrichment of specific molecules may occur,and furthermore a variety of periplasmic components and occasionally some inner membrane or cytoplasmic fractions.Although the detailed mechanisms of OMV biogenesis are not fully illuminated yet,several models have been proposed that demonstrate OMV biogenesis is an orchestrated well-regulated process.OMV secretion offers a way for both intra-and inter-species bacterial communication and for interaction or modulation of the bacterial environment.Therefore,OMVs have proven to be functionally versatile and important for bacterial physiology and survival of the host environment.In the host,OMVs are internalized via host cell endocytosis pathways,allowing them to subsequently trigger a variety of cellular responses.In this review,we discuss the recent advances in establishing the mechanisms involved in OMV biogenesis and the impact of OMVs on bacterial physiology and intracellular modulation of the host.展开更多
Gram-negative bacteria produce outer membrane vesicles(OMVs)that play a critical role in cell−cell communication and virulence.OMVs have emerged as promising therapeutic agents for various biological applications such...Gram-negative bacteria produce outer membrane vesicles(OMVs)that play a critical role in cell−cell communication and virulence.OMVs have emerged as promising therapeutic agents for various biological applications such as vaccines and targeted drug delivery.However,the full potential of OMVs is currently constrained by inherent heterogeneities,such as size and cargo differences,and traditional ensemble assays are limited in their ability to reveal OMV heterogeneity.To overcome this issue,we devised an innovative approach enabling the identification of various characteristics of individual OMVs.This method,employing fluorescence microscopy,facilitates the detection of variations in size and surface markers.To demonstrate our method,we utilize the oral bacterium Aggregatibacter actinomycetemcomitans(A.actinomycetemcomitans)which produces OMVs with a bimodal size distribution.As part of its virulence,A.actinomycetemcomitans secretes leukotoxin(LtxA)in two forms:soluble and surface associated with the OMVs.We observed a correlation between the size and toxin presence where larger OMVs were much more likely to possess LtxA compared to the smaller OMVs.In addition,we noted that,among the smallest OMVs(<100 nm diameter),the fractions that are toxin positive range from 0 to 30%,while the largest OMVs(>200 nm diameter)are between 70 and 100%toxin positive.展开更多
Rapid detection and quantification of outer membrane vesicle(OMV)are of both scientific value and clinical implications.However,limited tools are available for investigations of OMVs.Herein,we report a novel fluoresce...Rapid detection and quantification of outer membrane vesicle(OMV)are of both scientific value and clinical implications.However,limited tools are available for investigations of OMVs.Herein,we report a novel fluorescent probe with aggregation-induced emission(AIE)characteristics,namely,OEO-TPE-MEM(OTM),for OMV detection.OTM emits faintly in an aqueous medium,but its fluorescence could be effectively turned on upon interacting with bacteria bodies and OMVs produced by Gram-negative bacteria.Notably,OTM could provide quantitative information on bacterial membrane remodeling and OMV secretion and be applied to high-throughput screening of OMV-inducing agents.This study presents a powerful AIE probe for imaging and quantitative analysis of bacteria envelop and derived OMVs,which might be applied for evaluating research and clinical antimicrobial materials in future studies.展开更多
Tumor vaccines,a type of personalized tumor immunotherapy,have developed rapidly in recent decades.These vaccines evoke tumor antigen-specific T cells to achieve immune recognition and killing of tumor cells.Because t...Tumor vaccines,a type of personalized tumor immunotherapy,have developed rapidly in recent decades.These vaccines evoke tumor antigen-specific T cells to achieve immune recognition and killing of tumor cells.Because the immunogenicity of tumor antigens alone is insufficient,immune adjuvants and nanocarriers are often required to enhance anti-tumor immune responses.At present,vaccine carrier development often integrates nanocarriers and immune adjuvants.Among them,outer membrane vesicles(OMVs)are receiving increasing attention as a delivery platform for tumor vaccines.OMVs are natural nanovesicles derived from Gramnegative bacteria,which have adjuvant function because they contain pathogen associated molecular patterns.Importantly,OMVs can be functionally modified by genetic engineering of bacteria,thus laying a foundation for applications as a delivery platform for tumor nanovaccines.This review summarizes 5 aspects of recent progress in,and future development of,OMV-based tumor nanovaccines:strain selection,heterogeneity,tumor antigen loading,immunogenicity and safety,and mass production of OMVs.展开更多
Cancer vaccine efficacy relies on T cells eliciting tumor-specific adaptive immunity,with antigen-presenting cells,particularly dendritic cells(DCs),playing a crucial role.After capturing antigens,DCs migrate to lymph...Cancer vaccine efficacy relies on T cells eliciting tumor-specific adaptive immunity,with antigen-presenting cells,particularly dendritic cells(DCs),playing a crucial role.After capturing antigens,DCs migrate to lymph nodes,where they present antigens to naïve T cells and activate B and natural killer(NK)cells,thereby strengthening anti-tumor immune responses.However,limitations in immune adjuvants and insufficient antigen presentation hinder DCs migration,reducing vaccine effectiveness.This study introduces an outer membrane vesicle(OMV)-based platform engineered to express Vibrio vulnificus flagellin B(FlaB),a Toll-like receptor 5(TLR5)agonist.FlaB effectively activates DCs,enhances interactions with T cells,provides robust costimulatory signals,and promotes cytotoxic CD8^(+)T cell differentiation.Compared to unmodified OMV-Ag,the antigen-loaded OMV-FlaB-Ag nanovaccine significantly enhances DC function,eliciting potent antitumor responses and delaying tumor progression across multiple models.When combined with immune checkpoint inhibitors,it further amplifies antitumor immunity,markedly suppressing tumor growth and improving therapeutic outcomes.展开更多
Insufficient radiofrequency ablation(IRFA)of hepatocellular carcinoma(HCC)leads to alterations in epigenetic properties such as N^(6)-methyladenosine(m^(6)A)RNA methylation in tumor cells,which creates an immune-suppr...Insufficient radiofrequency ablation(IRFA)of hepatocellular carcinoma(HCC)leads to alterations in epigenetic properties such as N^(6)-methyladenosine(m^(6)A)RNA methylation in tumor cells,which creates an immune-suppressive tumor microenvironment capable of promoting residual tumor growth and recurrence and affecting the efficacy of RFA.In this study,the constructed STM-Mn@OMVs,which were produced through the rational functionalisation of bacterial-derived OMVs with Mn^(2+)ions and the methylation inhibitor STM2457,were found to effectively activate antitumor immunity.Our study shows that STM-Mn@OMVs can effectively promote dendritic cells(DCs)maturation,T cell activation,and STING pathway activation after endocytosis by cells,thus promoting immune cell infiltration.The STM-Mn@OMVs were able to promote cellular pyroptosis and synergistically activate the STING pathway.Furthermore,STM-Mn@OMVs promoted the increase of M1 macrophage phenotype in tumor-associated macrophages(TAMs)by reducing the infiltration of immunosuppressive cell populations such as regulatory T cells(Tregs)and myeloid-derived suppressor cells(MDSCs),thus reversing the suppressive immune microenvironment after IRFA to some extent.Ultimately,the growth of residual tumors was inhibited.In addition,the biosafety of STM-Mn@OMVs was demonstrated in this study.Therefore,the STM-Mn@OMVs constructed in this study have great potential for application in the field of RFA and immunotherapy for HCC.展开更多
Leveraging bacteria for cancer immunotherapy has gradually attracted wide attention since the discovery of“Cloey’s toxin.”However,one of the persistent challenges for bacteria-based therapy is striking a balance be...Leveraging bacteria for cancer immunotherapy has gradually attracted wide attention since the discovery of“Cloey’s toxin.”However,one of the persistent challenges for bacteria-based therapy is striking a balance between safety and immunogenicity.Genetically engineered bacteria with virulence factors removed could further enhance antitumor ability by integrating genetic elements.In addition,bacterial derivatives,including outer membrane vesicles(OMVs)produced by bacterial secretion and nanovesicles synthesized by modification of OMVs,could enhance antitumor immunity while improving safety.This perspective discusses the unique advantages of engineered bacteria and their derivatives for immunotherapy,as well as the challenges that need to be overcome to achieve clinical translation.展开更多
Photosynthetic bacteria(PSB)has shown significant potential as a drug or drug delivery system owing to their photothermal capabilities and antioxidant properties.Nevertheless,the actualization of their potential is im...Photosynthetic bacteria(PSB)has shown significant potential as a drug or drug delivery system owing to their photothermal capabilities and antioxidant properties.Nevertheless,the actualization of their potential is impeded by inherent constraints,including their considerable size,heightened immunogenicity and compromised biosafety.Conquering these obstacles and pursuing more effective solutions remains a top priority.Similar to extracellular vesicles,bacterial outer membrane vesicles(OMVs)have demonstrated a great potential in biomedical applications.OMVs from PSB encapsulate a rich array of bioactive constituents,including proteins,nucleic acids,and lipids inherited from their parent cells.Consequently,they emerge as a promising and practical alternative.Unfortunately,OMVs have suffered from low yield and inconsistent particle sizes.In response,bacteria-derived nanovesicles(BNVs),created through controlled extrusion,adeptly overcome the challenges associated with OMVs.However,the differences,both in composition and subsequent biological effects,between OMVs and BNVs remain enigmatic.In a groundbreaking endeavor,our study meticulously cultivates PSB-derived OMVs and BNVs,dissecting their nuances.Despite minimal differences in morphology and size between PSB-derived OMVs and BNVs,the latter contains a higher concentration of active ingredients and metabolites.Particularly noteworthy is the elevated levels of lysophosphatidylcholine(LPC)found in BNVs,known for its ability to enhance cell proliferation and initiate downstream signaling pathways that promote angiogenesis and epithelialization.Importantly,our results indicate that BNVs can accelerate wound closure more effectively by orchestrating a harmonious balance of cell proliferation and migration within NIH-3T3 cells,while also activating the EGFR/AKT/PI3K pathway.In contrast,OMVs have a pronounced aptitude in anti-cancer efforts,driving macrophages toward the M1 phenotype and promoting the release of inflammatory cytokines.Thus,our findings not only provide a promising methodological framework but also establish a definitive criterion for discerning the optimal application of OMVs and BNVs in addressing a wide range of medical conditions.展开更多
Extracellular vesicles(EVs)are secreted by both eukaryotes and prokaryotes,and are present in all biological fluids of vertebrates,where they transfer DNA,RNA,proteins,lipids,and metabolites from donor to recipient ce...Extracellular vesicles(EVs)are secreted by both eukaryotes and prokaryotes,and are present in all biological fluids of vertebrates,where they transfer DNA,RNA,proteins,lipids,and metabolites from donor to recipient cells in cell-to-cell communication.Some EV components can also indicate the type and biological status of their parent cells and serve as diagnostic targets for liquid biopsy.EVs can also natively carry or be modified to contain therapeutic agents(e.g.,nucleic acids,proteins,polysaccharides,and small molecules)by physical,chemical,or bioengineering strategies.Due to their excellent biocompatibility and stability,EVs are ideal nanocarriers for bioactive ingredients to induce signal transduction,immunoregulation,or other therapeutic effects,which can be targeted to specific cell types.Herein,we review EV classification,intercellular communication,isolation,and characterization strategies as they apply to EV therapeutics.This review focuses on recent advances in EV applications as therapeutic carriers from in vitro research towards in vivo animal models and early clinical applications,using representative examples in the fields of cancer chemotherapeutic drug,cancer vaccine,infectious disease vaccines,regenerative medicine and gene therapy.Finally,we discuss current challenges for EV therapeutics and their future development.展开更多
基金supported by the National Natural Science Foundation of China(No.31771189)the Wuhan Health Commission(No.WX18C17 and No.WX19Q31)the Natural Science Foundation of Hubei Province,China(No.2017CFA065 and No.WJ2019H378).
文摘Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins and other factors involved in various biological processes,includingβ-lactamase and antibiotic-resistance genes.This study aimed to reveal the transmission mechanism of OMV-mediated drug resistance of Klebsiella(K.)pneumoniae.Methods We selected CR-KP producing K.pneumoniae carbapenemase-2(KPC-2)to study whether they can transfer resistance genes through OMVs.The OMVs of CR-KP were obtained by ultracentrifugation,and incubated with carbapenem-sensitive K.pneumoniae for 4 h.Finally,the carbapenem-sensitive K.pneumoniae was tested for the presence of bla_(KPC-2)resistance gene and its sensitivity to carbapenem antibiotics.Results The existence of OMVs was observed by the electron microscopy.The extracted OMVs had bla_(KPC-2)resistance gene.After incubation with OMVs,bla_(KPC-2)resistance gene was detected in sensitive K.pneumoniae,and it became resistant to imipenem and meropenem.Conclusion This study demonstrated that OMVs isolated from KPC-2-producing CR-KP could deliver bla_(KPC-2)to sensitive K.pneumoniae,allowing the bacteria to produce carbapenemase,which may provide a novel target for innovative therapies in combination with conventional antibiotics for treating carbapenem-resistant Enterobacteriaceae.
基金the Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars(No.LR20C190001)the National Natural Science Foundation of China(No.31972833)+1 种基金the Fundamental Research Funds for the Provincial Universities of Zhejiang(No.SJ LZ2020001)the K.C.Wong Magna Fund at Ningbo University。
文摘Vibrio splendidus is an important opportunistic pathogen ubiquitously present in the marine environment,exhibiting virulence to a variety of cultured animals.The extracellular products secreted by V.splendidus are crucial to bacterial survival and virulence.In this study,the secretion of outer membrane vesicles(OMVs)by V.splendidus was determined,purified,and morphologically characterized.The protein composition of OMVs was analyzed by proteomic analysis.The results showed that approximately 120 proteins were contained in these OMVs,including outer membrane proteins,flagellins,ABC transporters,protease,and iron regulation proteins,etc.,which were involved in bacterial motility,formation of biofilms and the cell membrane components,and cellular localization based on their structural molecule activity,passive transmembrane transporter activity,channel activity,neurotransmitter receptor activity,extracellular ligand-gated ion channel activity,glutamate receptor activity,ligand-gated ion channel activity,and transmembrane signaling receptor activity.To explore the biological functions of OMVs in V.splendidus,the effects of OMVs on the bacterial adaption to iron limitation,antibiotic,and the coelomic fluid of the Apostichopus japonicus were confirmed.This study is the first time to show that V.splendidus secretes OMVs,and OMVs carry functional proteins that enhance bacterial survival under various stresses.
基金supported by the National Natural Science Foundation of China(Grant Nos.:52122317 and 22175120)the Science and Technology Foundation of Shenzhen City,China(Grant Nos.:JCYJ20210324142211031,RCYX20200714114525101,and RCYX20220809130438001)+5 种基金the Pearl River Talent Recruitment Program,China(Program No.:2019QN01Y103)the Medical-Engineering Interdisciplinary Research Foundation of Shenzhen University,China(Grant No.:2023YG021)the Research Team Cultivation Program of Shenzhen University,China(Program No.:2023QNT003)the Jiaxing Public Welfare Research Program Project,China(Program No.:2023AY11018)the project supported by Scientific Research Fund of Zhejiang Provincial Education Department,China(Project No.:Y202352075)Arshad Khan thanks the research support by King Abdullah International Medical Research Center(KAIMRC),Saudi Arabia through start up grant(Grant No.:SF23/006/R).
文摘Tumor treatment remains a significant medical challenge,with many traditional therapies causing notable side effects.Recent research has led to the development of immunotherapy,which offers numerous advantages.Bacteria inherently possess motility,allowing them to preferentially colonize tumors and modulate the tumor immune microenvironment,thus influencing the efficacy of immunotherapy.Bacterial outer membrane vesicles(OMVs)secreted by gram-negative bacteria are nanoscale lipid bilayer structures rich in bacterial antigens,pathogen-associated molecular patterns(PAMPs),various proteins,and vesicle structures.These features allow OMVs to stimulate immune system activation,generate immune responses,and serve as efficient drug delivery vehicles.This dual capability enhances the effectiveness of immunotherapy combined with chemotherapy or phototherapy,thereby improving anticancer drug efficacy.Current research has concentrated on engineering OMVs to enhance production yield,minimize cytotoxicity,and improve the safety and efficacy of treatments.Consequently,OMVs hold great promise for applications in tumor immunotherapy,tumor vaccine development,and drug delivery.This article provides an overview of the structural composition and immune mechanisms of OMVs,details various OMVs modification strategies,and reviews the progress in using OMVs for tumor treatment and their anti-tumor mechanisms.Additionally,it discusses the challenges faced in translating OMV-based anti-tumor therapies into clinical practice,aiming to provide a comprehensive understanding of OMVs'potential for in-depth research and clinical application.
基金National Natural Science Foundation of China(Grant No.81573381)CAMS Initiative for Innovative Medicine(Grant No.CAMS-I2M-1-012)
文摘In this study, liposomes were used to decorate bacterial outer membrane vesicles(OMVs), and decorated OMVs were evaluated in vitro. The OMVs of Pseudomonas aeruginosa were extracted by pressure-induced ammonium sulfate precipitation,and their particle size, distribution, zeta potential, protein content and stability were determined. Several types of liposomes were prepared by thin film dispersion method, and the OMVs were decorated by vortexing, sonication and extrusion, respectively. The interaction between liposome and OMV was studied with fluorescence resonance energy transfer(FRET) method. The results showed that the OMVs were spherical in shape and negatively charged. The vortexing method exerted little effect on the particle size and distribution of the decorated OMVs. The sonication process reduced the particle size and distribution of OMVs. FRET experiment indicated that the OMVs were decorated through membrane fusion. The above-mentioned results indicated that liposomes could successfully decorate OMVs, and decorated OMVs certainly widened their applications.
基金supported by the National Key Research and Development Program of China (2021YFA1201100,2021YFA1201103,X.Zhao)the National Natural Science Foundation of China (32471450,82402462,K.Cheng)+1 种基金the Beijing Municipal Science&Technology Commission (Z231100007223011,X.Zhao)the Beijing Natural Science Foundation (7244523,K.Cheng)。
文摘1 Introduction Outer-membrane vesicles (OMVs) are nanoscale,bilayered particles shed by Gram-negative bacteria [1].Enriched in lipopolysaccharides (LPS),outer-membrane proteins,and periplasmic cargos (Figure 1),OMVs are central to bacterial communication and host interaction,and they naturally traffic proteins,nucleic acids,and small molecules across biological barriers [2].These same traits,intrinsic immunogenicity,colloidal stability in complex fluids,and efficient cell entry,have positioned OMVs as attractive chassis for vaccines and drug delivery [3–5].Yet native vesicles are constrained by non-specific biodistribution,batch heterogeneity,reactogenic LPS,and limited control over cargo loading and release [6,7].These challenges necessitate the development of strategies to enhance their functionality and broaden their applications.
基金supported by the Hunan Provincial Science and Technology Plan(No.2016TP2002).
文摘Bacterial outer membrane vesicles(OMVs)are potent immuno-stimulating agents and have the potentials to be bioengineered as platforms for antitumor nanomedicine.In this study,OMVs are demonstrated as promising antitumor therapeutics.OMVs can lead to beneficial M2-to-M1 polarization of macrophages and induce pyroptosis to enhance antitumor immunity,but the therapeutic window of OMVs is narrow for its toxicity.We propose a bioengineering strategy to enhance the tumor-targeting ability of OMVs by macrophage-mediated delivery and improve the antitumor efficacy by co-loading of photosensitizer chlorin e6(Ce6)and chemotherapeutic drug doxorubicin(DOX)into OMVs as a therapeutic platform.We demonstrate that systemic injection of the DOX/Ce6-OMVs@M therapeutic platform,providing combinational photodynamic/chemo-/immunotherapy,eradicates triple-negative breast tumors in mice without side effects.Importantly,this strategy also effectively prevents tumor metastasis to the lung.This OMVs-based strategy with bioengineering may serve as a powerful therapeutic platform for a synergic antitumor therapy.
基金the National Key R&D Program of China(Grants No.2018YFA0208900,2018YFE0205300,and 2021YFA0909900)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB36000000)+5 种基金the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-010)the Beijing Natural Science Foundation of China(Grant No.Z200020)the Beijing Nova Program(Z201100006820031)the National Natural Science Foundation of China(Grants No.32171384,31800838,31820103004,31730032,and 51861145302)the Key Research Project of Frontier Science of the Chinese Academy of Sciences(Grant No.QYZDJ-SSW-SLH022)the Innovation Research Group of National Natural Science Foundation(Grant No.11621505).
文摘Nanocarriers with intrinsic immune adjuvant properties can activate the innate immune system while delivering tumor antigen,thus efficiently facilitating antitumor adaptive immunity.Bacteria-derived outer membrane vesicles(OMVs)are an excellent candidate due to their abundance of pathogen associated molecular patterns.However,during the uptake of OMVs by dendritic cells(DCs),the interaction between lipopolysaccharide and toll-like receptor 4 induces rapid DC maturation and uptake blockage,a phenomenon we refer to as“maturation-induced uptake obstruction"(MUO).Herein we decorated OMV with the DC-targeting aDEC205 antibody(OMV-DEC),which endowed the nanovaccine with an uptake mechanism termed as 4<not restricted to maturation via antibody modifying”(Normandy),thereby overcoming the MUO phenomenon.We also proved the applicability of this nanovaccine in identifying the human tumor neoantigens through rapid antigen display.In summary,this engineered OMV represents a powerful nanocarrier for personalized cancer vaccines,and this antibody modification strategy provides a reference to remodel the DC uptake pattern in nanocarrier design.
基金supported by the Beijing Natural Science Foundation(No.JQ21027)the National Natural Science Foundation of China(Nos.U2001224,32030062,21821005,and 82202028).
文摘Bacterial outer membrane vesicles(OMVs)are potent immunostimulants of regulating the tumor microenvironment(TME)for immunotherapy,and can be used to deliver drugs.However,the severe systemic inflammatory response triggered by OMVs upon intravenous(i.v.)injection has limited their application.Here,we developed a safe and effective strategy by conjugating doxorubicin-loaded serum albumin(SA-DOX,AD)onto the surface of OMVs using a matrix metalloproteinase(MMP)-cleavable peptide linker(cL).This approach enabled the dynamic shielding of OMVs to reduce the systemic side effects while simultaneously enhancing the anti-tumor effects through chemo-immunotherapy.Specifically,the resulting OMV-cL-AD formulation exhibited significantly enhanced accumulation at the tumor site after i.v.administration,facilitated by the SA decoration on the OMVs surface.Subsequently,the shield on the OMV-cL-AD was cleaved by the over-expressed MMP in the TME,leading to the release of both OMVs and AD.This process provided OMV-induced immunotherapy and DOX-induced chemotherapy,resulting in synergistic tumor inhibition.In conclusion,our work demonstrated the potential of OMV-cL-AD as an effective immunochemotherapy strategy that can prolong the survival time of mice without inducing side effects.
基金supported by National Natural Science Foundation of China(22225505,22322407,and 22174097)Fudan University Ruiqing Education Funding。
文摘Bacterial outer membrane vesicles(OMVs)have shown great potential in cancer immunotherapy.The isolation of OMVs from complex media with high purity and high bioactivity is the prerequisite of therapeutic applications,which remains highly challenging.Herein,we report a smart DNA hydrogel for the efficient isolation of OMVs from bacterial culture medium,which is further applied for localized cancer immunotherapy.The DNA hydrogel is constructed through the cross-linking of two ultralong DNA chains generated via rolling circle amplification(RCA).One chain contains polyvalent GN6 aptamer for the specific capture of OMVs,and the other contains polyvalent programmed death-1(PD-1)aptamer for the blocking of PD-1 immune checkpoint on the surface of T lymphocytes.The OMVs capsulated by DNA hydrogel maintain high immunostimulatory bioactivity.In the mouse model of melanoma,this OMVs-containing DNA hydrogel shows a remarkable tumor inhibition rate of∼95%.This smart DNA hydrogel represents a promising biomedical platform for the efficient isolation of bacterial-derived OMVs,and provides a powerful strategy for cancer immunotherapy.
基金supported by the Fundamental Research Funds for the Central UniversitiesNatural Science Foundation(Nos.2022-YGJC-86 and 2020-ZLLH-38 to Yiming Meng)of Liaoning ProvinceExcellent Talent Fund of Liaoning Province Cancer Hospital of Yiming Meng.
文摘Bacterial outer membrane vesicles(OMVs)are diminutive vesicles naturally released by Gram-negative bacteria.These vesicles possess distinctive characteristics that attract attention for their potential use in drug administration and immunotherapy in cancer treatment.Therapeutic medicines may be delivered via OMVs directly to the tumor sites,thereby minimizing exposure to healthy cells and lowering the risk of systemic toxicity.Furthermore,the activation of the immune system by OMVs has been demonstrated to facilitate the recognition and elimination of cancer cells,which makes them a desirable tool for immunotherapy.They can also be genetically modified to carry specific antigens,immunomodulatory compounds,and small interfering RNAs,enhancing the immune response to cancerous cells and silencing genes associated with disease progression.Combining OMVs with other cancer treatments like chemotherapy and radiation has shown promising synergistic effects.This review highlights the crucial role of bacterial OMVs in cancer,emphasizing their potential as vectors for novel cancer targeted therapies.As researchers delve deeper into the complexities of these vesicles and their interactions with tumors,there is a growing sense of optimism that this avenue of study will bring positive outcomes and renewed hope to cancer patients in the foreseeable future.
基金supported by the National Natural Science Foundation of China (32272479,32200142)Open Project Program of State Key Laboratory of Rice Biology (20190109)+3 种基金Open Project Program of State Key Laboratory for Biology of Plant Diseases and Insect Pests (SKLOF202201)Zhejiang Province Ecological Environment Research and Promotion Project (2020HT0009)Shanghai Committee of Science and Technology (19390743300 and 21ZR1435500)Chongqing Natural Science Foundation (CSTB2022NSCQ-MSX0524).
文摘Noncoding small RNAs(sRNAs)packaged in bacterial outer membrane vesicles(OMVs)function as novel mediators of interspecies communication.While the role of bacterial sRNAs in enhancing virulence is well established,the role of sRNAs in the interaction between OMVs from phytopathogenic bacteria and their host plants remains unclear.In this study,we employ RNA sequencing to characterize differentially pack-aged sRNAs in OMVs of the phytopathogen Xanthomonas oryzae pv.oryzicola(Xoc).Our candidate sRNA(Xosr001)was abundant in OMVs and involved in the regulation of OsJMT1 to impair host stomatal immu-nity.Xoc loads Xosr001 into OMVs,which are specifically ttransferred into the mechanical tissues of rice leaves.Xosr001 suppresses OsJMT1 transcript accumulation in vivo,leading to a reduction in MeJA accu-mulation in rice leaves.Furthermore,the application of synthesized Xosr001 sRNA to the leaves of OsJMT1-HA-OE transgenic line results in the suppression of OsJMT1 expression by Xosr001.Notably,the OsJMT1-HA-OE transgenic line exhibited attenuated stomatal immunity and disease susceptibility upon infection with DXosr001 compared to Xoc.These results suggest that Xosr001 packaged in Xoc OMVs functions to suppress stomatal immunity in rice.
基金supported by the National Natural Science Foundation of China(grant number 81871695).
文摘Outer membrane vesicles(OMVs)are spherical particles shed from the outer membrane of Gram-negative bacteria,which contain the typical components present in the outer membrane,although enrichment of specific molecules may occur,and furthermore a variety of periplasmic components and occasionally some inner membrane or cytoplasmic fractions.Although the detailed mechanisms of OMV biogenesis are not fully illuminated yet,several models have been proposed that demonstrate OMV biogenesis is an orchestrated well-regulated process.OMV secretion offers a way for both intra-and inter-species bacterial communication and for interaction or modulation of the bacterial environment.Therefore,OMVs have proven to be functionally versatile and important for bacterial physiology and survival of the host environment.In the host,OMVs are internalized via host cell endocytosis pathways,allowing them to subsequently trigger a variety of cellular responses.In this review,we discuss the recent advances in establishing the mechanisms involved in OMV biogenesis and the impact of OMVs on bacterial physiology and intracellular modulation of the host.
基金supported by grants from the National Institutes of Health to N.J.W.(R21GM134414,R15GM152918)and A.C.B.(R21DE027769,R21DE032153).
文摘Gram-negative bacteria produce outer membrane vesicles(OMVs)that play a critical role in cell−cell communication and virulence.OMVs have emerged as promising therapeutic agents for various biological applications such as vaccines and targeted drug delivery.However,the full potential of OMVs is currently constrained by inherent heterogeneities,such as size and cargo differences,and traditional ensemble assays are limited in their ability to reveal OMV heterogeneity.To overcome this issue,we devised an innovative approach enabling the identification of various characteristics of individual OMVs.This method,employing fluorescence microscopy,facilitates the detection of variations in size and surface markers.To demonstrate our method,we utilize the oral bacterium Aggregatibacter actinomycetemcomitans(A.actinomycetemcomitans)which produces OMVs with a bimodal size distribution.As part of its virulence,A.actinomycetemcomitans secretes leukotoxin(LtxA)in two forms:soluble and surface associated with the OMVs.We observed a correlation between the size and toxin presence where larger OMVs were much more likely to possess LtxA compared to the smaller OMVs.In addition,we noted that,among the smallest OMVs(<100 nm diameter),the fractions that are toxin positive range from 0 to 30%,while the largest OMVs(>200 nm diameter)are between 70 and 100%toxin positive.
基金Ming Wai Lau Centre for Reparative MedicineKarolinska Institutet+2 种基金Innovation and Technology Commission,Grant/Award Number:MHP/047/19Research Grants Council of Hong Kong,Grant/Award Number:C6014-20WNational Natural Science Foundation of China,Grant/Award Number:22005050。
文摘Rapid detection and quantification of outer membrane vesicle(OMV)are of both scientific value and clinical implications.However,limited tools are available for investigations of OMVs.Herein,we report a novel fluorescent probe with aggregation-induced emission(AIE)characteristics,namely,OEO-TPE-MEM(OTM),for OMV detection.OTM emits faintly in an aqueous medium,but its fluorescence could be effectively turned on upon interacting with bacteria bodies and OMVs produced by Gram-negative bacteria.Notably,OTM could provide quantitative information on bacterial membrane remodeling and OMV secretion and be applied to high-throughput screening of OMV-inducing agents.This study presents a powerful AIE probe for imaging and quantitative analysis of bacteria envelop and derived OMVs,which might be applied for evaluating research and clinical antimicrobial materials in future studies.
基金supported by grants from the National Key R&D Program of China(Grant No.2021YFA0909900,X.Z.)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-010,X.Z.)+2 种基金the Beijing Natural Science Foundation(Grant No.Z200020,X.Z.)the Beijing Nova Program(Grant No.Z201100006820031,X.Z.)the National Natural Science Foundation of China(Grant No.32171384,X.Z.).
文摘Tumor vaccines,a type of personalized tumor immunotherapy,have developed rapidly in recent decades.These vaccines evoke tumor antigen-specific T cells to achieve immune recognition and killing of tumor cells.Because the immunogenicity of tumor antigens alone is insufficient,immune adjuvants and nanocarriers are often required to enhance anti-tumor immune responses.At present,vaccine carrier development often integrates nanocarriers and immune adjuvants.Among them,outer membrane vesicles(OMVs)are receiving increasing attention as a delivery platform for tumor vaccines.OMVs are natural nanovesicles derived from Gramnegative bacteria,which have adjuvant function because they contain pathogen associated molecular patterns.Importantly,OMVs can be functionally modified by genetic engineering of bacteria,thus laying a foundation for applications as a delivery platform for tumor nanovaccines.This review summarizes 5 aspects of recent progress in,and future development of,OMV-based tumor nanovaccines:strain selection,heterogeneity,tumor antigen loading,immunogenicity and safety,and mass production of OMVs.
基金supported by the National Natural Science Foundation of China(Nos.U24A20765 and T2321005)Jiangsu Provincial Science and Technology Plan Special Fund(No.BM2023003)+1 种基金Jiangsu Provincial Medical Key Discipline(No.ZDXK202247)the Priority Academic Program Development of the Jiangsu Higher Education Institutes.
文摘Cancer vaccine efficacy relies on T cells eliciting tumor-specific adaptive immunity,with antigen-presenting cells,particularly dendritic cells(DCs),playing a crucial role.After capturing antigens,DCs migrate to lymph nodes,where they present antigens to naïve T cells and activate B and natural killer(NK)cells,thereby strengthening anti-tumor immune responses.However,limitations in immune adjuvants and insufficient antigen presentation hinder DCs migration,reducing vaccine effectiveness.This study introduces an outer membrane vesicle(OMV)-based platform engineered to express Vibrio vulnificus flagellin B(FlaB),a Toll-like receptor 5(TLR5)agonist.FlaB effectively activates DCs,enhances interactions with T cells,provides robust costimulatory signals,and promotes cytotoxic CD8^(+)T cell differentiation.Compared to unmodified OMV-Ag,the antigen-loaded OMV-FlaB-Ag nanovaccine significantly enhances DC function,eliciting potent antitumor responses and delaying tumor progression across multiple models.When combined with immune checkpoint inhibitors,it further amplifies antitumor immunity,markedly suppressing tumor growth and improving therapeutic outcomes.
基金supported by the National Natural Science Foundation of China(Nos.82402408 and 82271943)the Guangdong Special Support Program for Young Top-Notch Talents(No.2024TQ08Y995,China)+6 种基金the Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515012660,2022A1515220159 and 2023A1515220128,China)the Postdoctoral Fellowship Program of CPSF(No.BX20230068,China)the China Postdoctoral Science Foundation(2024M750452)the Guangzhou Science and Technology Plan Project(No.2023A03J1037,China)the Clinical Frontier Technology Program of the First Affiliated Hospital of Jinan University,China(No.JNU1AF-CFTP-2022-a01233)the Nonprofit Central Research Institute Fund of the Chinese Academy of Medical Sciences(2022-RC350-04,China)the CAMS Innovation Fund for Medical Sciences(Nos.2023-I2M-2-006 and 2023-I2M-QJ-010,China).
文摘Insufficient radiofrequency ablation(IRFA)of hepatocellular carcinoma(HCC)leads to alterations in epigenetic properties such as N^(6)-methyladenosine(m^(6)A)RNA methylation in tumor cells,which creates an immune-suppressive tumor microenvironment capable of promoting residual tumor growth and recurrence and affecting the efficacy of RFA.In this study,the constructed STM-Mn@OMVs,which were produced through the rational functionalisation of bacterial-derived OMVs with Mn^(2+)ions and the methylation inhibitor STM2457,were found to effectively activate antitumor immunity.Our study shows that STM-Mn@OMVs can effectively promote dendritic cells(DCs)maturation,T cell activation,and STING pathway activation after endocytosis by cells,thus promoting immune cell infiltration.The STM-Mn@OMVs were able to promote cellular pyroptosis and synergistically activate the STING pathway.Furthermore,STM-Mn@OMVs promoted the increase of M1 macrophage phenotype in tumor-associated macrophages(TAMs)by reducing the infiltration of immunosuppressive cell populations such as regulatory T cells(Tregs)and myeloid-derived suppressor cells(MDSCs),thus reversing the suppressive immune microenvironment after IRFA to some extent.Ultimately,the growth of residual tumors was inhibited.In addition,the biosafety of STM-Mn@OMVs was demonstrated in this study.Therefore,the STM-Mn@OMVs constructed in this study have great potential for application in the field of RFA and immunotherapy for HCC.
基金supported by the National Natural Science Foundation of China(nos.82222035 and 82372106)the Shenzhen Medical Research Found(no.B2302041).
文摘Leveraging bacteria for cancer immunotherapy has gradually attracted wide attention since the discovery of“Cloey’s toxin.”However,one of the persistent challenges for bacteria-based therapy is striking a balance between safety and immunogenicity.Genetically engineered bacteria with virulence factors removed could further enhance antitumor ability by integrating genetic elements.In addition,bacterial derivatives,including outer membrane vesicles(OMVs)produced by bacterial secretion and nanovesicles synthesized by modification of OMVs,could enhance antitumor immunity while improving safety.This perspective discusses the unique advantages of engineered bacteria and their derivatives for immunotherapy,as well as the challenges that need to be overcome to achieve clinical translation.
基金supported by the National Natural Science Foundation of China(32322045,32271420,31971304,and 21977024)The Beijing-Tianjin-Hebei Basic Research Cooperation Project(19JCZDJC64100)+5 种基金Cross-Disciplinary Project of Hebei University(DXK201916)One Hundred Talent Project of Hebei Province(E2018100002)National High-End Foreign Expert Recruitment Plan(G2022003007L)Science Fund for Creative Research Groups of Nature Science Foundation of Hebei Province(B2021201038)Natural Science Foundation of Hebei Province(B2023201108)Hebei Province Higher Education Science and Technology Research Project(JZX2023001).
文摘Photosynthetic bacteria(PSB)has shown significant potential as a drug or drug delivery system owing to their photothermal capabilities and antioxidant properties.Nevertheless,the actualization of their potential is impeded by inherent constraints,including their considerable size,heightened immunogenicity and compromised biosafety.Conquering these obstacles and pursuing more effective solutions remains a top priority.Similar to extracellular vesicles,bacterial outer membrane vesicles(OMVs)have demonstrated a great potential in biomedical applications.OMVs from PSB encapsulate a rich array of bioactive constituents,including proteins,nucleic acids,and lipids inherited from their parent cells.Consequently,they emerge as a promising and practical alternative.Unfortunately,OMVs have suffered from low yield and inconsistent particle sizes.In response,bacteria-derived nanovesicles(BNVs),created through controlled extrusion,adeptly overcome the challenges associated with OMVs.However,the differences,both in composition and subsequent biological effects,between OMVs and BNVs remain enigmatic.In a groundbreaking endeavor,our study meticulously cultivates PSB-derived OMVs and BNVs,dissecting their nuances.Despite minimal differences in morphology and size between PSB-derived OMVs and BNVs,the latter contains a higher concentration of active ingredients and metabolites.Particularly noteworthy is the elevated levels of lysophosphatidylcholine(LPC)found in BNVs,known for its ability to enhance cell proliferation and initiate downstream signaling pathways that promote angiogenesis and epithelialization.Importantly,our results indicate that BNVs can accelerate wound closure more effectively by orchestrating a harmonious balance of cell proliferation and migration within NIH-3T3 cells,while also activating the EGFR/AKT/PI3K pathway.In contrast,OMVs have a pronounced aptitude in anti-cancer efforts,driving macrophages toward the M1 phenotype and promoting the release of inflammatory cytokines.Thus,our findings not only provide a promising methodological framework but also establish a definitive criterion for discerning the optimal application of OMVs and BNVs in addressing a wide range of medical conditions.
基金supported by Tulane Weatherhead Endowment Fund (USA)
文摘Extracellular vesicles(EVs)are secreted by both eukaryotes and prokaryotes,and are present in all biological fluids of vertebrates,where they transfer DNA,RNA,proteins,lipids,and metabolites from donor to recipient cells in cell-to-cell communication.Some EV components can also indicate the type and biological status of their parent cells and serve as diagnostic targets for liquid biopsy.EVs can also natively carry or be modified to contain therapeutic agents(e.g.,nucleic acids,proteins,polysaccharides,and small molecules)by physical,chemical,or bioengineering strategies.Due to their excellent biocompatibility and stability,EVs are ideal nanocarriers for bioactive ingredients to induce signal transduction,immunoregulation,or other therapeutic effects,which can be targeted to specific cell types.Herein,we review EV classification,intercellular communication,isolation,and characterization strategies as they apply to EV therapeutics.This review focuses on recent advances in EV applications as therapeutic carriers from in vitro research towards in vivo animal models and early clinical applications,using representative examples in the fields of cancer chemotherapeutic drug,cancer vaccine,infectious disease vaccines,regenerative medicine and gene therapy.Finally,we discuss current challenges for EV therapeutics and their future development.
