Prognostic value and computer image analysis of p53 in mantle cell lymphoma.

P53 prognostic cut-off values differ between studies of mantle cell lymphoma (MCL), and its immunohistochemistry (IHC) interpretation is still based on semiquantitative estimation, which might be inaccurate. This study aimed to investigate the optimal cut-off value for p53 in predicting prognosis of patients with MCL and the possible use of computer image analysis to identify the positive rate of p53. We calculated p53 positive rate using QuPath software and compared it with the data obtained by manual counting and semiquantitative estimation. Survival curves were generated by using the Youden index and the Kaplan-Meier method. The chi-squared (χ2) test was used to compare MIPI, Ann Arbor stage, and cell morphology with p53. Spearman rank correlation test and Bland-Altman analysis were used to compare manual counting, computer image analysis and semiquantitative estimation, as well as the consistency between different observers. The optimal cut-off value of p53 for predicting prognosis was 20% in MCL patients. Patients with p53 ≥ 20% had a significantly worse overall survival (OS) than those with p53 < 20% (P < 0.0001). MCL patients with MIPI intermediate to high risk, Ann Arbor stage III-IV, and blastoid/pleomorphic variant cell morphology had more p53 ≥ 20%. There was a strong correlation between computer image analysis and manual counting of p53 from the same areas in MCL tissues (Spearman's rho = 0.966, P < 0.0001). The results of computer analysis are completely consistent between observers, and computer image analysis of Ki-67 can predict the prognosis of MCL patients. MCL patients with p53 ≥ 20% had a shorter OS and a tendency for MIPI intermediate to high risk, Ann Arbor stage III-IV, and blastoid/pleomorphic variant. Computer image analysis could determine the actual positive rate of p53 and Ki-67 and is a more attractive alternative than semiquantitative estimation in MCL.

Vasodilator-stimulated phosphoprotein promotes activation of hepatic stellate cells by regulating Rab11-dependent plasma membrane targeting of transforming growth factor beta receptors.

UNLABELLED: Liver microenvironment is a critical determinant for development and progression of liver metastasis. Under transforming growth factor beta (TGF-ß) stimulation, hepatic stellate cells (HSCs), which are liver-specific pericytes, transdifferentiate into tumor-associated myofibroblasts that promote tumor implantation (TI) and growth in the liver. However, the regulation of this HSC activation process remains poorly understood. In this study, we tested whether vasodilator-stimulated phosphoprotein (VASP) of HSCs regulated the TGF-ß-mediated HSC activation process and tumor growth. In both an experimental liver metastasis mouse model and cancer patients, colorectal cancer cells reaching liver sinusoids induced up-regulation of VASP and alpha-smooth muscle actin (α-SMA) in adjacent HSCs. VASP knockdown in HSCs inhibited TGF-ß-mediated myofibroblastic activation of HSCs, TI, and growth in mice. Mechanistically, VASP formed protein complexes with TGF-ß receptor II (TßRII) and Rab11, a Ras-like small GTPase and key regulator of recycling endosomes. VASP knockdown impaired Rab11 activity and Rab11-dependent targeting of TßRII to the plasma membrane, thereby desensitizing HSCs to TGF-ß1 stimulation. CONCLUSIONS: Our study demonstrates a requirement of VASP for TGF-ß-mediated HSC activation in the tumor microenvironment by regulating Rab11-dependent recycling of TßRII to the plasma membrane. VASP and its effector, Rab11, in the tumor microenvironment thus present therapeutic targets for reducing TI and metastatic growth in the liver.

Exosome-like nanoparticles from intestinal mucosal cells carry prostaglandin E2 and suppress activation of liver NKT cells.

Regulation and induction of anergy in NKT cells of the liver can inhibit autoimmune and antitumor responses by mechanisms that are poorly understood. We investigated the effects of PGE2, delivered by intestinal, mucus-derived, exosome-like nanoparticles (IDENs), on NKT cells in mice. In this study, we demonstrate that IDENs migrate to the liver where they induce NKT cell anergy. These effects were mediated by an IDENs' PGE2. Blocking PGE2 synthesis attenuated IDENs inhibition of induction of IFN-γ and IL-4 by α-galactosylceramide (α-GalCer)-stimulated liver NKT cells in a PGE2 E-type prostanoid 2/E-type prostanoid 4 receptor-mediated manner. Proinflammatory conditions enhanced the migration of IDENs to the liver where α-GalCer and PGE2 induced NKT anergy in response to subsequent α-GalCer stimulation. These findings demonstrate that IDENs carrying PGE2 can be transferred from the intestine to the liver, where they act as immune modulators, inducing an anergic-like state of NKT cells. These reagents might be developed as therapeutics for autoimmune liver diseases.

Targeted drug delivery to intestinal macrophages by bioactive nanovesicles released from grapefruit.

The gut mucosal immune system is considered to play an important role in counteracting potential adverse effects of food-derived antigens including nanovesicles. Whether nanovesicles naturally released from edible fruit work in a coordinated manner with gut immune cells to maintain the gut in a noninflammatory status is not known. Here, as proof of concept, we demonstrate that grapefruit-derived nanovesicles (GDNs) are selectively taken up by intestinal macrophages and ameliorate dextran sulfate sodium (DSS)-induced mouse colitis. These effects were mediated by upregulating the expression of heme oxygenase-1 (HO-1) and inhibiting the production of IL-1ß and TNF-α in intestinal macrophages. The inherent biocompatibility and biodegradability, stability at wide ranges of pH values, and targeting of intestinal macrophages led us to further develop a novel GDN-based oral delivery system. Incorporating methotrexate (MTX), an anti-inflammatory drug, into GDNs and delivering the MTX-GDNs to mice significantly lowered the MTX toxicity when compared with free MTX, and remarkably increased its therapeutic effects in DSS-induced mouse colitis. These findings demonstrate that GDNs can serve as immune modulators in the intestine, maintain intestinal macrophage homeostasis, and can be developed for oral delivery of small molecule drugs to attenuate inflammatory responses in human disease.

PDGF receptor-α promotes TGF-ß signaling in hepatic stellate cells via transcriptional and posttranscriptional regulation of TGF-ß receptors.

Platelet-derived growth factor (PDGF) and transforming growth factor-ß (TGF-ß) signaling are required for hepatic stellate cell (HSC) activation under pathological conditions such as liver metastatic tumor growth. These two signaling pathways are functionally divergent; PDGF signaling promotes proliferation and migration of HSCs, and TGF-ß induces transdifferentiation of quiescent HSCs into myofibroblasts. Although PDGF signaling is implicated in TGF-ß-mediated epithelial mesenchymal transition of tumor cells, the role of PDGF receptors in TGF-ß activation of HSCs has not been investigated. Here we report that PDGF receptor-α (PDGFR-α) is required for TGF-ß signaling of cultured human HSCs although HSCs express both PDGF-α and -ß receptors. PDGFR-α knockdown inhibits TGF-ß-induced phosphorylation and nuclear accumulation of SMAD2 with no influence on AKT or ERK phosphorylation associated with noncanonical TGF-ß signaling. PDGFR-α knockdown suppresses TGF-ß receptor I (TßRI) but increases TßRII gene transcription. At the protein level, PDGFR-α is recruited to TßRI/TßRII complexes by TGF-ß stimulation. PDGFR-α knockdown blocks TGF-ß-mediated internalization of TßRII and induces accumulation of TßRII at the plasma membrane, thereby inhibiting TGF-ß phosphorylation of SMAD2. Functionally, knockdown of PDGFR-α reduces paracrine effects of HSCs on colorectal cancer cell proliferation and migration in vitro. In mice and patients, colorectal cancer cell invasion of the liver induces upregulation of PDGFR-α of HSCs. In summary, our finding that PDGFR-α knockdown inhibits SMAD-dependent TGF-ß signaling by repressing TßRI transcriptionally and blocking endocytosis of TGF-ß receptors highlights a convergence of PDGF and TGF-ß signaling for HSC activation and PDGFR-α as a therapeutic target for liver metastasis and other settings of HSC activation.

Intestinal mucus-derived nanoparticle-mediated activation of Wnt/ß-catenin signaling plays a role in induction of liver natural killer T cell anergy in mice.

UNLABELLED: The Wnt/ß-catenin pathway has been known to play a role in induction of immune tolerance, but its role in the induction and maintenance of natural killer T (NKT) cell anergy is unknown. We found that activation of the Wnt pathways in the liver microenvironment is important for induction of NKT cell anergy. We identified a number of stimuli triggering Wnt/ß-catenin pathway activation, including exogenous NKT cell activator, glycolipid α-GalCer, and endogenous prostaglandin E2 (PGE2). Glycolipid α-GalCer treatment of mice induced the expression of wnt3a and wnt5a in the liver and subsequently resulted in a liver microenvironment that induced NKT cell anergy to α-GalCer restimulation. We also found that circulating PGE2 carried by nanoparticles is stable, and that these nanoparticles are A33(+) . A33(+) is a marker of intestinal epithelial cells, which suggests that the nanoparticles are derived from the intestine. Mice treated with PGE2 associated with intestinal mucus-derived exosome-like nanoparticles (IDENs) induced NKT cell anergy. PGE2 treatment leads to activation of the Wnt/ß-catenin pathway by inactivation of glycogen synthase kinase 3ß of NKT cells. IDEN-associated PGE2 also induces NKT cell anergy through modification of the ability of dendritic cells to induce interleukin-12 and interferon-ß in the context of both glycolipid presentation and Toll-like receptor-mediated pathways. CONCLUSION: These findings demonstrate that IDEN-associated PGE2 serves as an endogenous immune modulator between the liver and intestines and maintains liver NKT cell homeostasis. This finding has implications for development of NKT cell-based immunotherapies. (HEPATOLOGY 2013).

Grape exosome-like nanoparticles induce intestinal stem cells and protect mice from DSS-induced colitis.

Food-derived exosome-like nanoparticles pass through the intestinal tract throughout our lives, but little is known about their impact or function. Here, as a proof of concept, we show that the cells targeted by grape exosome-like nanoparticles (GELNs) are intestinal stem cells whose responses underlie the GELN-mediated intestinal tissue remodeling and protection against dextran sulfate sodium (DSS)-induced colitis. This finding is further supported by the fact that coculturing of crypt or sorted Lgr5⁺ stem cells with GELNs markedly improved organoid formation. GELN lipids play a role in induction of Lgr5⁺ stem cells, and the liposome-like nanoparticles (LLNs) assembled with lipids from GELNs are required for in vivo targeting of intestinal stem cells. Blocking ß-catenin-mediated signaling pathways of GELN recipient cells attenuates the production of Lgr5⁺ stem cells. Thus, GELNs not only modulate intestinal tissue renewal processes, but can participate in the remodeling of it in response to pathological triggers.

Selenomethionine alleviates chronic heat stress-induced breast muscle injury and poor meat quality in broilers via relieving mitochondrial dysfunction and endoplasmic reticulum stress.

In the present study, the chronic heat stress (CHS) broiler model was developed to investigate the potential protection mechanism of organic selenium (selenomethionine, SeMet) on CHS-induced skeletal muscle growth retardation and poor meat quality. Four hundred Arbor Acres male broilers (680 ± 70 g, 21 d old) were grouped into 5 treatments with 8 replicates of 10 broilers per replicate. Broilers in the control group were raised in a thermoneutral environment (22 ± 2 °C) and fed with a basal diet. The other four treatments were exposed to hyperthermic conditions (33 ± 2 °C, 24 h in each day) and fed on the basal diet supplied with SeMet at 0.0, 0.2, 0.4, and 0.6 mg Se/kg, respectively, for 21 d. Results showed that CHS reduced (P < 0.05) the growth performance, decreased (P < 0.05) the breast muscle weight and impaired the meat quality of breast muscle in broilers. CHS induced protein metabolic disorder in breast muscle, which increased (P < 0.05) the expression of caspase 3, caspase 8, caspase 9 and ubiquitin proteasome system related genes, while decreased the protein expression of P-4EBP1. CHS also decreased the antioxidant capacity and induced mitochondrial stress and endoplasmic reticulum (ER) stress in breast muscle, which increased (P < 0.05) the ROS levels, decreased the concentration of ATP, increased the protein expression of HSP60 and CLPX, and increased (P < 0.05) the expression of ER stress biomarkers. Dietary SeMet supplementation linearly increased (P < 0.05) breast muscle Se concentration and exhibited protective effects via up-regulating the expression of the selenotranscriptome and several key selenoproteins, which increased (P < 0.05) body weight, improved meat quality, enhanced antioxidant capacity and mitigated mitochondrial stress and ER stress. What's more, SeMet suppressed protein degradation and improved protein biosynthesis though inhibiting the caspase and ubiquitin proteasome system and promoting the mTOR-4EBP1 pathway. In conclusion, dietary SeMet supplementation increases the expression of several key selenoproteins, alleviates mitochondrial dysfunction and ER stress, improves protein biosynthesis, suppresses protein degradation, thus increases the body weight and improves meat quality of broilers exposed to CHS.

Tumor cell cross talk with tumor-associated leukocytes leads to induction of tumor exosomal fibronectin and promotes tumor progression.

Exosomes participate in intercellular communication, but most data published are based on exosomes released from in vitro cultured cells that do not communicate with neighboring cells located in the same microenvironment as the exosomal-producing cells in vivo. In this study, our data show that co-culture of leukocytes isolated from breast tumor tissue leads to uptake of fibronectin (FN) on or in the tumor exosomes (Exo(fib+)). The induction of FN and exosomal uptake is tumor tissue derived and leukocyte specific, because leukocytes isolated from the peripheral blood of naïve mice failed to induce FN uptake by tumor exosomes. Furthermore, depletion of both CD25(+) cells and Gr-1(+) cells from tumor-associated leukocytes causes a reduction of Exo(fib+), suggesting that tumor-associated CD25(+) cells and Gr-1(+) cells participate in FN production and uptake by tumor exosomes, resulting in Exo(fib+). As a result of tumor cells absorbing Exo(fib+), two major events are induced: focal adhesion kinase/Src-dependent signaling pathways are activated, and the production of proinflammatory cytokines and metalloproteinase 9 is enhanced in response to absorbing exosomes. This, in turn, enhances tumor cell invasion in vitro and in vivo. Collectively, our findings provide evidence that exosomes released from freshly excised tumor tissue cells that have communicated/interacted with immune cells gain new immune evasion capacity.

Plant homologue constitutive photomorphogenesis 9 (COP9) signalosome subunit CSN5 regulates innate immune responses in macrophages.

COP9 plays a role in plant innate immunity. The role of COP9 in mammalian innate immune responses is unknown. Here, we show that the COP9 signalosome subunit 5 (CSN5) is required for activation of proinflammatory kinases p38 and Erk and for down-regulation of the expression of genes regulated by nuclear factor E2-related factor 2. Mice with myeloid-specific CSN5 deficiency have lower mortality in polymicrobial sepsis. CSN5 is required for both Toll-like receptor (TLR) and reactive oxygen species-mediated deneddylation of Cul3, which is essential for Cul3/Keap1-mediated degradation of nuclear factor E2-related factor 2. On the basis of our results COP9 subunit CSN5 is considered to be an essential component of mammalian innate immunity.

STDAN: Deformable Attention Network for Space-Time Video Super-Resolution.

The target of space-time video super-resolution (STVSR) is to increase the spatial-temporal resolution of low-resolution (LR) and low-frame-rate (LFR) videos. Recent approaches based on deep learning have made significant improvements, but most of them only use two adjacent frames, that is, short-term features, to synthesize the missing frame embedding, which cannot fully explore the information flow of consecutive input LR frames. In addition, existing STVSR models hardly exploit the temporal contexts explicitly to assist high-resolution (HR) frame reconstruction. To address these issues, in this article, we propose a deformable attention network called STDAN for STVSR. First, we devise a long short-term feature interpolation (LSTFI) module that is capable of excavating abundant content from more neighboring input frames for the interpolation process through a bidirectional recurrent neural network (RNN) structure. Second, we put forward a spatial-temporal deformable feature aggregation (STDFA) module, in which spatial and temporal contexts in dynamic video frames are adaptively captured and aggregated to enhance SR reconstruction. Experimental results on several datasets demonstrate that our approach outperforms state-of-the-art STVSR methods. The code is available at https://github.com/littlewhitesea/STDAN.

Hydroxy Selenomethionine Exert Different Protective Effects Against Dietary Oxidative Stress-Induced Inflammatory Responses in Spleen and Thymus of Pigs.

Oxidative stress (OS) is widespread in animal husbandry, which causes edema in immune organs and suppresses immune function of animals. Selenium (Se) is an essential trace element involved in immune regulation and improves animals' immunity. In present study, growing and finishing pigs were used to determine the protective effects of the new organic Se (hydroxy selenomethionine, OH-SeMet) on dietary oxidative stress (DOS) induced inflammatory responses, and the corresponding response of selenotranscriptome in spleen and thymus. Forty castrated male pigs (25.0 ± 3.0 kg) were randomly grouped into 5 dietary treatments (n = 8) and fed on basal diet (formulated with normal corn and normal oils) or oxidized diet (formulated with aged corn and oxidized oils) supplied with 0.0, 0.3, 0.6, or 0.9 mg Se/kg OH-SeMet, after 16 weeks, the corresponding indicators were determined. Results showed that DOS moderately increased the spleen and thymus index, decreased the antioxidant capacity of serum, spleen and thymus, and increased the concentration of serum inflammatory cytokines (IL-6 and TNF-α). The inflammatory response in spleen and thymus under DOS were discrepancies, DOS increased the expression of inflammation-related gene (IFN-ß and TNF-α) in thymus, while exhibited no impact on that of the spleen. Dietary OH-SeMet supplementation exhibited protective effects, which decreased the spleen and thymus index, improved the antioxidant capacity of serum, spleen and thymus, and decreased the serum IL-1ß and IL-6 levels. Se supplementation exhibited limited impact on the inflammation-related genes in spleen, except decreased the mRNA expression of IL-8. On the contrary, Se supplementation showed more impact on that of the thymus, which decreased the mRNA expression of IL-8 and TNF-α, increased the expression of IFN-ß, IL-6, IL-10, and MCP1. In addition, selenotranscriptome responsive to dietary Se levels in spleen and thymus were discrepancies. Se supplementation increased the mRNA expression of  the selenotranscriptome in thymus, while exhibited limited impact on that of in spleen. In conclusion, dietary OH-SeMet supplementation mitigates the DOS-induced immunological stress by increasing the antioxidant capacity and altering the expression of inflammation-related genes and selenotranscriptome in immune organs, and these response in spleen and thymus were discrepancies.

Identifying CD1c as a potential biomarker by the comprehensive exploration of tumor mutational burden and immune infiltration in diffuse large B cell lymphoma.

Background: Tumor mutational burden (TMB) is a valuable prognostic biomarker. This study explored the predictive value of TMB and the potential association between TMB and immune infiltration in diffuse large B-cell lymphoma (DLBCL). Methods: We downloaded the gene expression profile, somatic mutation, and clinical data of DLBCL patients from The Cancer Genome Atlas (TCGA) database. We classified the samples into high-and low-TMB groups to identify differentially expressed genes (DEGs). Functional enrichment analyses were performed to determine the biological functions of the DEGs. We utilized the cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm to estimate the abundance of 22 immune cells, and the significant difference was determined by the Wilcoxon rank-sum test between the high- and low-TMB group. Hub gene had been screened as the prognostic TMB-related immune biomarker by the combination of the Immunology Database and Analysis Portal (ImmPort) database and the univariate Cox analysis from the Gene Expression Omnibus (GEO) database including six DLBCL datasets. Various database applications such as Tumor Immune Estimation Resource (TIMER), CellMiner, konckTF, and Genotype-Tissue Expression (GTEx) verified the functions of the target gene. Wet assay confirmed the target gene expression at RNA and protein levels in DLBCL tissue and cell samples. Results: Single nucleotide polymorphism (SNP) occurred more frequently than insertion and deletion, and C > T was the most common single nucleotide variant (SNV) in DLBCL. Survival analysis showed that the high-TMB group conferred poor survival outcomes. A total of 62 DEGs were obtained, and 13 TMB-related immune genes were identified. Univariate Cox analysis results illustrated that CD1c mutation was associated with lower TMB and manifested a satisfactory clinical prognosis by analysis of large samples from the GEO database. In addition, infiltration levels of immune cells in the high-TMB group were lower. Using the TIMER database, we systematically analyzed that the expression of CD1c was positively correlated with B cells, neutrophils, and dendritic cells and negatively correlated with CD8+ T cells, CD4+ T cells, and macrophages. Drug sensitivity showed a significant positive correlation between CD1c expression level and clinical drug sensitivity from the CellMiner database. CREB1, AHR, and TOX were used to comprehensively explore the regulation of CD1c-related transcription factors and signaling pathways by the KnockTF database. We searched the GETx database to compare the mRNA expression levels of CD1c between DLBCL and normal tissues, and the results suggested a significant difference between them. Moreover, wet experiments were conducted to verify the high expression of CD1c in DLBCL at the RNA and protein levels. Conclusions: Higher TMB correlated with poor survival outcomes and inhibited the immune infiltrates in DLBCL. Our results suggest that CD1c is a TMB-related prognostic biomarker.

Treatment of brain inflammatory diseases by delivering exosome encapsulated anti-inflammatory drugs from the nasal region to the brain.

In this study, exosomes used to encapsulate curcumin (Exo-cur) or a signal transducer and activator of transcription 3 (Stat3) inhibitor, i.e., JSI124 (Exo-JSI124) were delivered noninvasively to microglia cells via an intranasal route. The results generated from three inflammation-mediated disease models, i.e., a lipopolysaccharide (LPS)-induced brain inflammation model, experimental autoimmune encephalitis and a GL26 brain tumor model, showed that mice treated intranasally with Exo-cur or Exo-JSI124 are protected from LPS-induced brain inflammation, the progression of myelin oligodendrocyte glycoprotein (MOG) peptide induced experimental autoimmune encephalomyelitis (EAE), and had significantly delayed brain tumor growth in the GL26 tumor model. Intranasal administration of Exo-cur or Exo-JSI124 led to rapid delivery of exosome encapsulated drug to the brain that was selectively taken up by microglial cells, and subsequently induced apoptosis of microglial cells. Our results demonstrate that this strategy may provide a noninvasive and novel therapeutic approach for treating brain inflammatory-related diseases.

Inflammation-Related Genes Serve as Prognostic Biomarkers and Involve in Immunosuppressive Microenvironment to Promote Gastric Cancer Progression.

Gastric cancer (GC) is a typical inflammatory-related malignant tumor which is closely related to helicobacter pylori infection. Tumor inflammatory microenvironment plays a crucial role in tumor progression and affect the clinical benefit from immunotherapy. In recent years, immunotherapy for gastric cancer has achieved promising outcomes, but not all patients can benefit from immunotherapy due to tumor heterogeneity. In our study, we identified 29 differentially expressed and prognostic inflammation-related genes in GC and normal samples. Based on those genes, we constructed a prognostic model using a least absolute shrinkage and selection operator (LASSO) algorithm, which categorized patients with GC into two groups. The high-risk group have the characteristics of "cold tumor" and have a poorer prognosis. In contrast, low-risk group was "hot tumor" and had better prognosis. Targeting inflammatory-related genes and remodeling tumor microenvironment to turn "cold tumor" into "hot tumor" may be a promising solution to improve the efficacy of immunotherapy for patients with GC.

Identification of FCER1G related to Activated Memory CD4+ T Cells Infiltration by Gene Co-expression Network and Construction of a Risk Prediction Module in Diffuse Large B-Cell Lymphoma.

Diffuse large B cell lymphoma (DLBCL) is a group of biologically heterogeneous tumors with different prognoses. The tumor microenvironment plays a vital role in the tumorigenesis and development of DLBCL, and activated memory CD4+ T cells are an essential component of immunological cells in the lymphoma microenvironment. So far, there are few reports about activated memory CD4+T cells infiltration and related genes in the DLBCL tumor microenvironment. This study obtained the mRNA expression profile information of the testing GSE87371 dataset and another six validation datasets (GSE53786, GSE181063, GSE10846, GSE32918, GSE32018, GSE9327, GSE3892, TCGA-DLBC) from the GEO and TCGA databases. Weighted Gene Co-expression Network Analysis (WGCNA) screened gene module associated with activated memory CD4+ T cells infiltration. CIBERSORT and TIMER (immune cells infiltrating estimation analysis tools) were used to identify the relationship between activated memory CD4+ T cells and genes associated with immune infiltrating cells in the tumor microenvironment. The least absolute shrinkage and selection operator (LASSO) built the risk prediction model and verified it using nomogram and Kaplan-Meier analysis. Further functional characterization includes Gene Ontology, KEGG pathway analysis and Gene Set Enrichment Analysis (GSEA) to investigate the role and underlying mechanisms of these genes. These results suggest that the expression of FCER1G can reflect the invasion of activated memory CD4+ T cells in DLBCL, which provides a new idea for studying the tumor microenvironment and may become a potential predictive biomarker for the assessment of DLBCL.

TLR2-mediated expansion of MDSCs is dependent on the source of tumor exosomes.

Exosomes released from tumor cells having been shown to induce interleukin-6 release from myeloid-derived suppressor cells in a Toll-like receptor 2/Stat3-dependent manner. In this study, we show that exosomes released from tumor cells re-isolated from syngeneic mice are capable of inducing interleukin-6 in a Toll-like receptor 2-independent manner, whereas the data generated from exosomes of tumor cells having undergone numerous in vitro passages induce interleukin-6 in a Toll-like receptor 2-dependent manner. This discrepancy may be due to the source of tumor cells used to generate the exosomes for this study. These results suggest that exosomes released from tumor cells that are not within a tumor microenvironment may not realistically represent the role of tumor exosomes in vivo. This is an important consideration since frequently passing tumor cells in vivo is an accepted practice for studying tumor exosome-mediated inflammatory responses.

Contribution of MyD88 to the tumor exosome-mediated induction of myeloid derived suppressor cells.

In this study we observed that mice pretreated with tumor exosomes had a significant acceleration of tumor metastasis in the lung. Tumor metastasis correlated significantly with an increase in recruitment of more Myeloid-derived suppressor cells (MDSCs) in the lung of C57BL/6j (B6) mice pretreated with tumor exosomes. These effects were blunted when MyD88 knockout (KO) mice were pretreated with tumor exosomes. MDSCs induced by tumor exosomes and isolated from wild-type B6 mice also more potently inhibited T cell activation and induction of interleukin-6 and tumor necrosis factor-alpha than MDSCs isolated from the lung of MyD88 KO mice. In vitro, addition of tumor exosomes to bone marrow-derived CD11b(+)Gr-1(+) cells isolated from wild-type B6 mice resulted in more cytokine production, including tumor necrosis factor-alpha, interleukin-6, and the chemokine CCL2, than CD11b(+)Gr-1(+) cells isolated from MyD88 KO mice. Moreover, lower levels of CCL2 were observed in the lungs in MyD88 KO mice pretreated with tumor exosomes than that in wild-type mice. Together these data demonstrate a pivotal role for MyD88 in tumor exosome-mediated expansion of MDSCs and tumor metastasis.

A novel nanoparticle drug delivery system: the anti-inflammatory activity of curcumin is enhanced when encapsulated in exosomes.

Monocyte-derived myeloid cells play vital roles in inflammation-related autoimmune/inflammatory diseases and cancers. Here, we report that exosomes can deliver anti-inflammatory agents, such as curcumin, to activated myeloid cells in vivo. This technology provides a means for anti-inflammatory drugs, such as curcumin, to target the inflammatory cells as well as to overcome unwanted off-target effects that limit their utility. Using exosomes as a delivery vehicle, we provide evidence that curcumin delivered by exosomes is more stable and more highly concentrated in the blood. We show that the target specificity is determined by exosomes, and the improvement of curcumin activity is achieved by directing curcumin to inflammatory cells associated with therapeutic, but not toxic, effects. Furthermore, we validate the therapeutic relevance of this technique in a lipopolysaccharide (LPS)-induced septic shock mouse model. We further show that exosomes, but not lipid alone, are required for the enhanced anti-inflammatory activity of curcumin. The specificity of using exosomes as a drug carrier creates opportunities for treatments of many inflammation-related diseases without significant side effects due to innocent bystander or off-target effects.