Genetically engineered membrane-based nanoengagers for immunotherapy of pancreatic cancer.

Modulating macrophages presents a promising avenue in tumor immunotherapy. However, tumor cells have evolved mechanisms to evade macrophage activation and phagocytosis. Herein, we introduced a bispecific antibody-based nanoengager to facilitate the recognition and phagocytosis of tumor cells by macrophages. Specifically, we genetically engineered two single chain variable fragments (scFv) onto cell membrane: anti-CD40 scFv for engaging with macrophages and anti-Claudin18.2 (CLDN18.2) scFv for interacting with tumor cells. These nanoengagers were further constructed by coating scFv-anchored membrane into PLGA nanoparticle core. Our developed nanoengagers significantly boosted immune responses, including increased recognition and phagocytosis of tumor cells by macrophages, enhanced activation and antigen presentation, and elevated cytotoxic T lymphocyte activity. These combined benefits resulted in enhancing antitumor efficacy against highly aggressive "cold" pancreatic cancer. Overall, this study offers a versatile nanoengager design for immunotherapy, achieved through genetically engineering to incorporate antibody-anchored membrane.

OX40L-Armed Oncolytic Virus Boosts T-cell Response and Remodels Tumor Microenvironment for Pancreatic Cancer Treatment.

Rationale: The resistance of pancreatic ductal adenocarcinoma (PDAC) to immunotherapies is caused by the immunosuppressive tumor microenvironment (TME) and dense extracellular matrix. Currently, the efficacy of an isolated strategy targeting stromal desmoplasia or immune cells has been met with limited success in the treatment of pancreatic cancer. Oncolytic virus (OV) therapy can remodel the TME and damage tumor cells either by directly killing them or by enhancing the anti-tumor immune response, which holds promise for the treatment of PDAC. This study aimed to investigate the therapeutic effect of OX40L-armed OV on PDAC and to elucidate the underlying mechanisms. Methods: Murine OX40L was inserted into herpes simplex virus-1 (HSV-1) to construct OV-mOX40L. Its expression and function were assessed using reporter cells, cytopathic effect, and immunogenic cell death assays. The efficacy of OV-mOX40L was then evaluated in a KPC syngeneic mouse model. Tumor-infiltrating immune and stromal cells were analyzed using flow cytometry and single-cell RNA sequencing to gain insight into the mechanisms of oncolytic virotherapy. Results: OV-mOX40L treatment delayed tumor growth in KPC tumor-bearing C57BL/6 mice. It also boosted the tumor-infiltrating CD4+ T cell response, mitigated cytotoxic T lymphocyte (CTL) exhaustion, and reduced the number of regulatory T cells. The treatment of OV-mOX40L reprogrammed macrophages and neutrophils to a more pro-inflammatory anti-tumor state. In addition, the number of myofibroblastic cancer-associated fibroblasts (CAF) was reduced after treatment. Based on single-cell sequencing analysis, OV-mOX40L, in combination with anti-IL6 and anti-PD-1, significantly extended the lifespan of PDAC mice. Conclusion: OV-mOX40L converted the immunosuppressive tumor immune microenvironment to a more activated state, remodeled the stromal matrix, and enhanced T cell response. OV-mOX40L significantly prolonged the survival of PDAC mice, either as a monotherapy or in combination with synergistic antibodies. Thus, this study provides a multimodal therapeutic strategy for pancreatic cancer treatment.

A novel autophagy-related long non-coding RNAs signature predicting progression-free interval and I-131 therapy benefits in papillary thyroid carcinoma.

This study aimed to explore the prognostic and predictive value of autophagy-related lncRNAs in papillary thyroid carcinoma (PTC). The expression data of autophagy-related genes and lncRNAs of the PTC patients were obtained from TCGA database. Autophagy-related-differentially expressed lncRNAs (DElncs) were identified and used to establish the lncRNAs signature predicting patients' progression-free interval (PFI) in the training cohort. Its performance was assessed in the training cohort, validation cohort, and entire cohort. Effects of the signature on I-131 therapy were also explored. We identified 199 autophagy-related-DElncs and constructed a novel six-lncRNAs signature was constructed based on these lncRNAs. This signature had a good predictive performance and was superior to TNM stages and previous clinical risk scores. I-131 therapy was found to be associated with favorable prognosis in patients with high-risk scores but not those with low-risk scores. Gene set enrichment analysis suggested that a series of hallmark gene sets were enriched in the high-risk subgroup. Single-cell RNA sequencing analysis suggested that the lncRNAs were mainly expressed in thyroid cells but not stromal cells. In conclusion, our study constructed a well-performed six-lncRNAs signature to predict PFI and I-131 therapy benefits in PTC.

Tumor Cell Nanovaccines Based on Genetically Engineered Antibody-Anchored Membrane.

Despite the promise in whole-tumor cell vaccines, a key challenge is to overcome the lack of costimulatory signals. Here, agonistic-antibody-boosted tumor cell nanovaccines are reported by genetically engineered antibody-anchored membrane (AAM) technology, capable of effectively activating costimulatory pathways. Specifically, the AAM can be stably constructed following genetic engineering of tumor cell membranes with anti-CD40 single chain variable fragment (scFv), an agonistic antibody to induce costimulatory signals. The nanovaccines are versatilely designed and obtained based on the anti-CD40 scFv-anchored membrane and nanotechnology. Following vaccination, the anti-CD40 scFv-anchored membrane nanovaccine (Nano-AAM/CD40) significantly facilitates dendritic cell maturation in CD40-humanized transgenic mice and subsequent adaptive immune responses. Compared to membrane-based nanovaccines alone, the enhanced antitumor efficacy in both "hot" and "cold" tumor models of the Nano-AAM/CD40 demonstrates the importance of agonistic antibodies in development of tumor-cell-based vaccines. To expand the design of nanovaccines, further incorporation of cell lysates into the Nano-AAM/CD40 to conceptually construct tumor cell-like nanovaccines results in boosted immune responses and improved antitumor efficacy against malignant tumors inoculated into CD40-humanized transgenic mice. Overall, this genetically engineered AAM technology provides a versatile design of nanovaccines by incorporation of tumor-cell-based components and agonistic antibodies of costimulatory immune checkpoints.

Construction of an IL12 and CXCL11 armed oncolytic herpes simplex virus using the CRISPR/Cas9 system for colon cancer treatment.

Oncolytic viruses are an emerging cancer treatment modality with promising results in clinical trials. The new generation of oncolytic viruses are genetically modified to enhance virus selectivity for tumor cells and allow local expression of therapeutic genes in tumors. The traditional technique for viral genome engineering based on homologous recombination using a bacterial artificial chromosome (BAC) system is laborious and time-consuming. With the advent of the CRISPR/Cas9 system, the efficiency of gene editing in human cells and other organisms has dramatically increased. In this report, we successfully applied the CRISPR/Cas9 technique to construct an HSV-based oncolytic virus, where the ICP34.5 coding region was replaced with the therapeutic genes murine interleukin 12 (IL12, p40-p35) and C-X-C motif chemokine ligand 11 (CXCL11), and ICP47 gene was deleted. The combination of IL12 and CXCL11 in oncolytic viruses showed considerable promise in colorectal cancer (CRC) treatment. Overall, our study describes genetic modification of the HSV-1 genome using the CRISPR/Cas9 system and provides evidence from principle studies for engineering of the HSV genome to express foreign genes.

An armed oncolytic virus enhances the efficacy of tumor-infiltrating lymphocyte therapy by converting tumors to artificial antigen-presenting cells in situ.

The full potential of tumor-infiltrating lymphocyte (TIL) therapy has been hampered by the inadequate activation and low persistence of TILs, as well as inefficient neoantigen presentation by tumors. We transformed tumor cells into artificial antigen-presenting cells (aAPCs) by infecting them with a herpes simplex virus 1 (HSV-1)-based oncolytic virus encoding OX40L and IL12 (OV-OX40L/IL12) to provide local signals for optimum T cell activation. The infected tumor cells displayed increased expression of antigen-presenting cell-related markers and induced enhanced T cell activation and killing in coculture with TILs. Combining OV-OX40L/IL12 and TIL therapy induced complete tumor regression in patient-derived xenograft and syngeneic mouse tumor models and elicited an antitumor immunological memory. In addition, the combination therapy produced aAPC properties in tumor cells, activated T cells, and reprogrammed macrophages to a more M1-like phenotype in the tumor microenvironment. This combination strategy unleashes the full potential of TIL therapy and warrants further evaluation in clinical studies.

CD40L-armed oncolytic herpes simplex virus suppresses pancreatic ductal adenocarcinoma by facilitating the tumor microenvironment favorable to cytotoxic T cell response in the syngeneic mouse model.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant cancers worldwide. Despite the promising outcome of immune checkpoint inhibitors and agonist antibody therapies in different malignancies, PDAC exhibits high resistance due to its immunosuppressive tumor microenvironment (TME). Ameliorating the TME is thus a rational strategy for PDAC therapy. The intratumoral application of oncolytic herpes simplex virus-1 (oHSV) upregulates pro-inflammatory macrophages and lymphocytes in TME, and enhances the responsiveness of PDAC to immunotherapy. However, the antitumor activity of oHSV remains to be maximized. The aim of this study is to investigate the effect of the CD40L armed oHSV on the tumor immune microenvironment, and ultimately prolong the survival of the PDAC mouse model. METHODS: The membrane-bound form of murine CD40L was engineered into oHSV by CRISPR/Cas9-based gene editing. oHSV-CD40L induced cytopathic effect and immunogenic cell death were determined by microscopy and flow cytometry. The expression and function of oHSV-CD40L was assessed by reporter cell assay. The oHSV-CD40L was administrated intratumorally to the immune competent syngeneic PDAC mouse model, and the leukocytes in TME and tumor-draining lymph node were analyzed by multicolor flow cytometry. Intratumoral cytokines were determined by ELISA. RESULTS: Intratumoral application of oHSV-CD40L efficiently restrained the tumor growth and prolonged the survival of the PDAC mouse model. In TME, oHSV-CD40L-treated tumor accommodated more maturated dendritic cells (DCs), which in turn activated T helper 1 and cytotoxic CD8+ T cells in an interferon-γ-dependent and interleukin-12-dependent manner. In contrast, the regulatory T cells were significantly reduced in TME by oHSV-CD40L treatment. Repeated dosing and combinational therapy extended the lifespan of PDAC mice. CONCLUSION: CD40L-armed oncolytic therapy endues TME with increased DCs maturation and DC-dependent activation of cytotoxic T cells, and significantly prolongs the survival of the model mice. This study may lead to the understanding and development of oHSV-CD40L as a therapy for PDAC in synergy with immune checkpoint blockade.

Induction of meiosis by embryonic gonadal somatic cells differentiated from pluripotent stem cells.

BACKGROUND: Depletion of oocytes leads to ovarian aging-associated infertility, endocrine disruption and related diseases. Excitingly, unlimited oocytes can be generated by differentiation of primordial germ cell like cells (PGCLCs) from pluripotent stem cells. Nevertheless, development of oocytes and follicles from PGCLCs relies on developmentally matched gonadal somatic cells, only available from E12.5 embryos in mice. It is therefore imperative to achieve an in vitro source of E12.5 gonadal somatic cells. METHODS: We explored to identify small molecules, which can induce female embryonic stem cells (ESCs) into gonadal somatic cell like cells. RESULTS: Using RNA-sequencing, we identified signaling pathways highly upregulated in E12.5_gonadal somatic cells (E12.5_GSCs). Through searching for the activators of these pathways, we identified small-molecule compounds Vitamin C (Vc) and AM580 in combination (V580) for inducing differentiation of female embryonic stem cells (ESCs) into E12.5_GSC-like cells (E12.5_GSCLCs). After V580 treatment for 6 days and sorted by a surface marker CD63, the cell population yielded a transcriptome profile similar to that of E12.5_GSCs, which promoted meiosis progression and folliculogenesis of primordial germ cells. This approach will contribute to the study of germ cell and follicle development and oocyte production and have implications in potentially treating female infertility. CONCLUSION: ESCs can be induced into embryonic gonadal somatic cell like cells by small molecules.

Validation of PM2.5 model particle through physicochemical evaluation and atherosclerotic plaque formation in ApoE-/- mice.

PM2.5 particles are regarded as prominent risk factors that contribute to the development of atherosclerosis. However, the composition of PM2.5 is rather complicated. This study aimed to provide a model particle that simulates the behavior of actual PM2.5, for subsequent use in exploring mechanisms and major complications arising from PM2.5. To establish model particles of PM2.5, a series of monodisperse SiO2 microspheres with different average grain diameters were mixed according to the size distribution of actual PM2.5. The organic carbon (OC) was removed from PM2.5 and coated onto the SiO2 model particle, to formulate simulant PM2.5. Results showed that the size distribution of the model particle was highly approximate to that of the PM2.5 core. The polycyclic aromatic hydrocarbon (PAHs) composition profile of the simulated PM2.5 were approximate to PM2.5, and loading efficiency was approximately 80%-120%. Furthermore, compared to the control, SiO2-only model particle had negligible cytotoxicity on cell viability and oxidative stress of HUVECs, and marginal effect on the lipid metabolism and atherosclerotic plaque formation in ApoE-/- mice. In contrast, simulated PM2.5 exhibited similar cytotoxic and detrimental effects on lipid metabolism and atherosclerotic plaque formation with actual PM2.5. Traffic-related PM2.5 had negative effects on endothelial function and led to the formation of atherosclerosis via oxidative stress. The simulated PM2.5 simulated the outcomes of actual PM2.5 exposure. Here, we show that SiO2 particle model cores coated with OC could significantly assist in the evaluation of the effects of specific organic compositions bound on PM2.5, specifically in the context of environmental health and safety.

The interaction between Vav1 and EBNA1 promotes survival of Burkitt's lymphoma cells by down-regulating the expression of Bim.

Vav1 is a guanine nucleotide exchange factor (GEF) predominantly expressed in hematopoietic cells, and functions in the development and antigen-stimulated response of lymphocytes. Burkitt's lymphoma (BL) is characterized as transformed B cell lymphoma, and is highly associated with Epstein-Barr virus (EBV). EBV nuclear antigen 1 (EBNA1) is the only viral protein expressed across all three types of latency and essential for the persistence of EBV genome. It is not clear yet how EBNA1 contributes to the growth advantage of latently infected cells such as in EBV+ lymphoma B cells. Here, we reported that Vav1 interacts with EBNA1 via its C-terminal SH3 domain. This interaction suppresses the expression of a pro-apoptotic Bcl-2 family member, Bim, resulting in the resistance of the BL cells to apoptotic inductions. Our data uncovered Vav1 as a novel target for EBNA1, and suggested a pro-survival role of Vav1 in the pathogenesis of EBV associated BLs.

Role of Aif1 in regulation of cell death under environmental stress in Candida albicans.

Apoptosis-inducing factor (AIF) is a conserved flavoprotein localized in the mitochondria, inducing apoptosis after translocation into the nucleus. However, its role in the important fungal pathogen, Candida albicans, remains to be investigated. In this study, we find that the C. albicans AIF protein Aif1, similar to its homologues in other organisms, is localized at the mitochondria and translocated into the nucleus under apoptosis-inducing conditions. Moreover, deletion of AIF1 causes attenuated apoptosis in this pathogen under apoptosis-inducing conditions, such as the treatment of 2 mm H2 O2 , 10 mm acetic acid or 0.08 mg/l caspofungin, and its overexpression enhances this process. Interestingly, treatment with high levels of these agents leads to reversed sensitivity of aif1Δ/Δ and the overexpression strain AIF1ov. In addition, the virulence of C. albicans is not affected by deletion or overexpression of AIF1. Hence, C. albicans Aif1, as a mitochondria-localized protein, plays a dual role in the regulation of cell death under different concentrations of the stress-caused agents. Copyright © 2016 John Wiley & Sons, Ltd.

Parthenolide induces autophagy via the depletion of 4E-BP1.

Parthenolide (PTL) is a sesquiterpene lactone isolated from feverfew and exhibits potent antitumor activity against various cancers. Many studies indicate that PTL treatment leads to apoptosis, however, the mechanism has not been defined. Here, we observed that cells underwent autophagy shortly after PTL treatment. Inhibition of autophagy by knocking out autophagy associated gene atg5 blocked PTL-induced apoptosis. Surprisingly, PTL decreased the level of translation initiation factor eIF4E binding protein 1 (4E-BP1) in correlation with autophagy. Ectopic expression or shRNA knockdown of 4E-BP1 further verified the effect of 4E-BP1 on PTL-induced autophagy. Meanwhile, PTL elevated the cellular reactive oxygen species (ROS) which located upstream of the depletion of 4E-BP1, and contributed to the consequent autophagy. This study revealed 4E-BP1 as a trigger for PTL-induced autophagy and may lead to therapeutic strategy to enhance the efficacy of anticancer drugs.

Estrogen induces Vav1 expression in human breast cancer cells.

Vav1, a guanine nucleotide exchange factor (GEF) for Rho family GTPases, is a hematopoietic protein involved in a variety of cellular events. In recent years, aberrant expression of Vav1 has been reported in non-hematopoietic cancers including human breast cancer. It remains to be answered how Vav1 is expressed and what Vav1 does in its non-resident tissues. In this study, we aimed to explore the mechanism for Vav1 expression in breast cancer cells in correlation with estrogen-ER pathway. We not only verified the ectopic expression of Vav1 in human breast cancer cell lines, but also observed that Vav1 expression was induced by 17ß-estradiol (E2), a typical estrogen receptor (ER) ligand, in ER-positive cell lines. On the other hand, Tamoxifen, a selective estrogen receptor modulator (SERM), and ICI 182,780, an ER antagonist, suppressed the expression of Vav1. The estrogen receptor modulating Vav1 expression was identified to be α form, not ß. Furthermore, treatment of E2 increased the transcription of vav1 gene by enhancing the promoter activity, though there was no recognizable estrogen response element (ERE). Nevertheless, two regions at the vav1 gene promoter were defined to be responsible for E2-induced activation of vav1 promoter. Chromatin immunoprecipitation (ChIP) and co-immunoprecipitation (Co-IP) analyses suggested that ERα might access to the vav1 promoter via interacting with transcription factors, c-Myb and ELF-1. Consequently, the enhanced expression of Vav1 led to the elevation of Cyclin D1 and the progression of cell cycle. The present study implies that estrogen-ER modulates the transcription and expression of Vav1, which may contribute to the proliferation of cancerous cells.

Vav1 increases Bcl-2 expression by selective activation of Rac2-Akt in leukemia T cells.

Vav proteins are guanine nucleotide exchange factors (GEFs) that activate a group of small G proteins (GTPases). Vav1 is predominantly expressed in hematopoietic cells, whereas Vav2 and Vav3 are ubiquitously distributed in almost all human tissues. All three Vav proteins contain conserved structural motifs and associate with a variety of cellular activities including proliferation, migration, and survival. Previous observation with Jurkat leukemia T cells showed that Vav1 possessed anti-apoptotic activity by enhancing Bcl-2 transcription. However the mechanism has not been unveiled. Here, we explored the effectors of Vav1 in promoting Bcl-2 expression in Jurkat cells and revealed that Rac2-Akt was specifically evoked by the expression of Vav1, but not Vav2 or Vav3. Although all three Vav isoforms existed in Jurkat cells, Rac2 was distinguishably activated by Vav1 and that led to enhanced Bcl-2 expression and cell survival. Akt was modulated downstream of Vav1-Rac2, and the activation of Akt was indispensable in the enhanced transcription of Bcl-2. Intriguingly, neither Vav2 nor Vav3 was able to activate Rac2-Akt pathway as determined by gene silencing approach. Our data illustrated a unique role of Vav1 in T leukemia survival by selectively triggering Rac2-Akt axis and elevating the expression of anti-apoptotic Bcl-2.

Decreased Vδ2 γδ T cells associated with liver damage by regulation of Th17 response in patients with chronic hepatitis B.

BACKGROUND: γδ T cells comprise a small subset of T cells and play a protective role against cancer and viral infections; however, their precise role in patients with chronic hepatitis B remains unclear. METHODS: Flow cytometry and immunofunctional assays were performed to analyze the impact of Vδ2 γδ (Vδ2) T cells in 64 immune-activated patients, 22 immune-tolerant carriers, and 30 healthy controls. RESULTS: The frequencies of peripheral and hepatic Vδ2 T cells decreased with disease progression from immune tolerant to immune activated. In the latter group of patients, the decreases in peripheral and intrahepatic frequencies of Vδ2 T cells reversely correlated with alanine aminotransferase levels and histological activity index. These activated terminally differentiated memory phenotypic Vδ2 T cells exhibited impaired abilities in proliferation and chemotaxis, while maintained a relative intact interferon (IFN) γ production. Importantly, Vδ2 T cells, in vitro, significantly suppressed the production of cytokines associated with interleukin 17-producing CD4+ T (Th17) cells through both cell contact-dependent and IFN-γ-dependent mechanisms. CONCLUSIONS: Inflammatory microenvironment in IA patients result in decreased numbers of Vδ2 T cells, which play a novel role by regulating the pathogenic Th17 response to protect the liver in patients with chronic hepatitis B.

The N-terminal 20-amino acid region of guanine nucleotide exchange factor Vav1 plays a distinguished role in T cell receptor-mediated calcium signaling.

Vav1 is a guanine nucleotide exchange factor (GEF) specifically expressed in hematopoietic cells. It consists of multiple structural domains and plays important roles in T cell activation. The other highly conserved isoforms of Vav family, Vav2 and Vav3, are ubiquitously expressed in human tissues including lymphocytes. All three Vav proteins activate Rho family small GTPases, which are involved in a variety of biological processes during T cell activation. Intensive studies have demonstrated that Vav1 is indispensable for T cell receptor (TCR)-mediated signal transduction, whereas Vav2 and Vav3 function as GEFs that overlap with Vav1 on TCR-induced cytoskeleton reorganization. T cells lacking Vav1 exhibited severe defect in TCR-mediated calcium elevation, indicating that the co-existing Vav2 and Vav3 did not compensate Vav1 in calcium signaling. What is the functional particularity of Vav1 in lymphocytes? In this study, we identified the N-terminal 20 amino acids of Vav1 in the calponin homology (CH) domain to be essential for its interaction with calmodulin (CaM) that leads to TCR-induced calcium mobilization. Substitution of the 1-20 amino acids of Vav1 with those of Vav2 or Vav3 abolished the association with CaM, and the N-terminal mutations of Vav1 failed to potentiate normal TCR-induced calcium mobilization, that in turn, suspended nuclear factor of activated T cells (NFAT) activation and IL-2 production. This study highlights the importance of the N-terminal 20 aa of Vav1 for CaM binding, and provides new insights into the distinguished and irreplaceable role of Vav1 in T cell activation and signal transduction.

The distinct role of guanine nucleotide exchange factor Vav1 in Bcl-2 transcription and apoptosis inhibition in Jurkat leukemia T cells.

AIM: To investigate a novel function of proto-oncogene Vav1 in the apoptosis of human leukemia Jurkat cells. METHODS: Jurkat cells, Jurkat-derived vav1-null cells (J.Vav1) and Vav1-reconstituted J.WT cells were treated with a Fas agonist antibody, IgM clone CH11. Apoptosis was determined using propidium iodide (PI) staining, Annexin-V staining, DNA fragmentation, cleavage of caspase 3/caspase 8, and poly (ADP-ribose) polymerase (PARP). Mitochondria transmembrane potential (ΔΨ(m)) was measured using DiOC(6)(3) staining. Transcription and expression of the Bcl-2 family of proteins were evaluated using semi-quantitative RT-PCR and Western blot, respectively. Bcl-2 promoter activity was analyzed using luciferase reporter assays. RESULTS: Cells lacking Vav1 were more sensitive to Fas-mediated apoptosis than Jurkat and J.WT cells. J.Vav1 cells lost mitochondria transmembrane potential (ΔΨ(m)) more rapidly upon Fas induction. These phenotypes could be rescued by re-expression of Vav1 in J.Vav1 cells. The expression of Vav1 increased the transcription of pro-survival Bcl-2. The guanine nucleotide exchange activity of Vav1 was required for enhancing Bcl-2 promoter activity, and the Vav1 downstream substrate, small GTPase Rac2, was likely involved in the control of Bcl-2 expression. CONCLUSION: Vav1 protects Jurkat cells from Fas-mediated apoptosis by promoting Bcl-2 transcription through its GEF activity.

Effects of humidity on the plasma-catalytic removal of low-concentration BTX in air.

Effects of relative humidity (30%, 50% and 80% RH) on the removal of low-concentration benzene, toluene and p-xylene (BTX mixture) in air by non-thermal plasma (NTP) and the combination of NTP and MnO(x)/Al(2)O(3) catalyst (CPC) were systematically investigated in a link tooth wheel-cylinder plasma reactor. A long-term (150 h) CPC experiment under 30% RH was also conducted to investigate the stability of the catalyst. Results show that increasing humidity inhibits the O(3) production in plasma and its decomposition over the catalyst. As for BTX conversion, increasing humidity suppresses the benzene conversion by both NTP and CPC; although higher humidity slightly promotes the toluene conversion by NTP, it negatively influences that by CPC; while the conversion of p-xylene by both NTP and CPC is insensitive to the humidity levels. Irrespective of the RH, the introduction of MnO(x)/Al(2)O(3) catalyst significantly promotes BTX conversion and improves the energy efficiency. On the other hand, CPC under 30% RH shows the best performance towards CO(x) formation during BTX oxidation processes. However, for a specific input energy of 10 J L(-1) in this study, organic intermediates generated and accumulated over the catalyst surface, resulting in a slight deactivation of the MnO(x)/Al(2)O(3) catalyst after 150-h reactions.