Thrombopoietin receptor agonist antibody for treating chemotherapy-induced thrombocytopenia.

BACKGROUND: Thrombocytopenia is a common complication in cancer patients undergoing chemotherapy. Chemotherapy-induced thrombocytopenia (CIT) leads to dose reduction and treatment delays, lowering chemotherapy efficacy and survival rate. Thus, rapid recovery and continuous maintenance of platelet count during chemotherapy cycles are crucial in patients with CIT. Thrombopoietin (TPO) and its receptor, myeloid proliferative leukemia (MPL) protein, play a major role in platelet production. Although several MPL agonists have been developed to regulate thrombopoiesis, none have been approved for the management of CIT due to concerns regarding efficacy or safety. Therefore, the development of effective MPL agonists for treating CIT needs to be further expanded. METHODS: Anti-MPL antibodies were selected from the human combinatorial antibody phage libraries using phage display. We identified 2R13 as the most active clone among the binding antibodies via cell proliferation assay using BaF3/MPL cells. The effect of 2R13 on megakaryocyte differentiation was evaluated in peripheral blood CD34+ cells by analyzing megakaryocyte-specific differentiation markers (CD41a+ and CD42b+) and DNA ploidy using flow cytometry. The 2R13-induced platelet production was examined in 8- to 10-week-old wild-type BALB/c female mice and a thrombocytopenia mouse model established by intraperitoneal injection of 5-fluorouracil (150 mg/kg). The platelet counts were monitored twice a week over 14 days post-initiation of treatment with a single injection of 2R13, or recombinant human TPO (rhTPO) for seven consecutive days. RESULTS: We found that 2R13 specifically interacted with MPL and activated its signaling pathways. 2R13 stimulated megakaryocyte differentiation, evidenced by increasing the proportion of high-ploidy (≥ 8N) megakaryocytes in peripheral blood-CD34+ cells. The platelet count was increased by a single injection of 2R13 for up to 14 days. Injection of 5-fluorouracil considerably reduced the platelet count by day 4, which was recovered by 2R13. The platelets produced by 2R13 sustained a higher count than that achieved using seven consecutive injections of rhTPO. CONCLUSIONS: Our findings suggest that 2R13 is a promising therapeutic agent for CIT treatment.

Efficacy of Polydeoxyribonucleotide in Promoting the Healing of Diabetic Wounds in a Murine Model of Streptozotocin-Induced Diabetes: A Pilot Experiment.

We assessed the efficacy of polydeoxyribonucleotide (PDRN) in accelerating the healing of diabetic wounds in a murine model of streptozotocin (STZ)-induced diabetes. After the creation of diabetic wounds, the mice of the PDRN SC, PDRN IP and PBS groups received a subcutaneous, an intra-peritoneal injection of PDRN and a subcutaneous injection of PBS, respectively. After euthanasia, time-dependent changes in the wound diameter and histologic scores were measured and vascular endothelial growth factor (VEGF), transforming growth factor-ß1 (TGF-ß1) and collagen types I and III were assessed for their expression levels. The PDRN SC and the PDRN IP groups showed a significantly smaller diameter of diabetic wounds, significantly higher histologic scores, a significantly greater expression of VEGF, a significantly lower expression of TGF-ß1 and a significantly greater expression of collagen types I and III as compared with the PBS group (p < 0.05 or 0.0001). In conclusion, PDRN might be effective in promoting the healing of diabetic wounds in a murine model of STZ-induced diabetes.

Impact of Obesity on the IL-6 Immune Marker and Th17 Immune Cells in C57BL/6 Mice Models with Imiquimod-Induced Psoriasis.

Obese psoriatic patients experience higher disease severity and exhibit poorer treatment responses and clinical outcomes. It has been proposed that proinflammatory cytokines produced by adipose tissue exacerbate psoriasis; however, the role of obesity in psoriasis remains unclear. This study aimed to elucidate the role of obesity in the pathogenesis of psoriasis, focusing on immunological changes. To induce obesity, mice were fed a high-fat diet for 20 weeks. We then applied imiquimod to the skin on a mouse's back for seven consecutive days to induce psoriasis and scored lesion severity every day for seven days. Cytokine levels in serum and the Th17 cell population in the spleen and draining lymph nodes were studied to identify immunological differences. The clinical severity was more remarkable, and histologically the epidermis was also significantly thicker in the obese group. Increased levels of IL-6 and TNF-α were observed in serum after psoriasis. They were elevated to a greater degree, with greater expansion of the functional Th17 cell population in the obese group. It is concluded that obesity could exacerbate psoriasis through mechanisms that involve elevated proinflammatory cytokine secretion and an expanded Th17 cell population.

Combined treatment with anti-HER2/neu and anti-4-1BB monoclonal antibodies induces a synergistic antitumor effect but requires dose optimization to maintain immune memory for protection from lethal rechallenge.

Human epidermal growth factor receptor type 2 (HER2)-positive breast cancer that is treated with anti-HER2/neu monoclonal antibody (mAb) is not free from late recurrences. Addition of anti-4-1BB mAb to anti-HER2/neu mAb has been demonstrated to strengthen the cytotoxic antitumor response. Our study expands on this by revealing the influence of anti-4-1BB mAb addition on the immune memory of anti-HER2/neu mAb. We designed murine breast cancer models by implanting TUBO and TUBO-P2J cell lines in mice, which were then treated with anti-HER2/neu and/or anti-4-1BB mAb. After complete surgical and/or chemical regression of the tumor, the mice were rechallenged with a second injection of cancer cells. Notably, anti-HER2/neu and anti-4-1BB mAb combination therapy had a synergistic antitumor effect at the initial treatment. However, the combination therapy did not evoke immune memory, allowing the tumors to thrive at rechallenge with reduced CD44+ expression in CD8+ T cells. Immune memory was also impaired when anti-4-1BB mAb was administered to naive CD8+ T cells but was sustained when this was administered to activated CD8+ T cells. In an attempt to resist the loss of immune memory, we controlled the dose of anti-4-1BB mAb to optimize the stimulation of activated CD8+ T cells. Immune memory was achieved with the dose regulation of anti-4-1BB mAb to 1 mg/kg in our model. Our study demonstrates the importance in understanding the adaptive immune mechanism of anti-HER2/neu and anti-4-1BB mAb combination therapy and suggests a dose optimization strategy is necessary to ensure development of successful immune memory.

Role of the JAK/STAT pathway in a streptozotocin-induced diabetic retinopathy mouse model.

PURPOSE: The Janus tyrosine kinase and signal transducers and activators of transcription (JAK/STAT) pathway is involved in vascular endothelial growth factor (VEGF) expression, but the role of this pathway in diabetic retinopathy (DR) remains unclear. We investigated the role of the JAK/STAT pathway on DR and VEGF expression using a streptozotocin (STZ)-induced DR mouse model. METHODS: Cultured ARPE-19 cells were exposed to high-glucose conditions and treated with JAK/STAT inhibitors (JAK inhibitor I [JAKiI], tofacitinib, STAT3 inhibitor [STAT3i]) for 48 h. Reverse-transcription polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were used to investigate p-JAK/STAT and VEGF expression. Diabetes was induced by intraperitoneal injection of STZ (50 mg/kg) in C57BL/6 mice for 5 days. DR development was evaluated every 4 weeks. JAK/STAT inhibitors were administered for 8 weeks. Immunofluorescence was used to measure the activation status of the JAK/STAT pathway and VEGF production in the retinal tissue. RESULTS: In ARPE-19 cells exposed to high-glucose conditions, the mRNA and secretory protein levels of VEGF, p-JAK1, p-JAK2, p-STAT3, and p-STAT5 levels were significantly increased. Treatment with JAKiI, tofacitinib, and STAT3i significantly suppressed VEGF to basal levels at both the mRNA and secretory levels in vitro. In STZ-induced mice, retinal vascular leakage, p-JAK1, p-JAK2, p-JAK3, p-STAT3, and VEGF were significantly increased after diabetes induction. Diabetes-induced retinal vascular leakage was significantly reduced by treatment with JAKiI and tofacitinib. Increased p-JAK1 and VEGF in STZ-induced mice were significantly reduced by JAKiI (p < 0.05, p < 0.001) and tofacitinib (p < 0.001, respectively). CONCLUSION: JAK1 may be more involved in VEGF production and DR progression in mice than JAK2, JAK3, and STAT3.

Benzyl Isothiocyanate Attenuates Inflammasome Activation in Pseudomonas aeruginosa LPS-Stimulated THP-1 Cells and Exerts Regulation through the MAPKs/NF-κB Pathway.

Inflammasomes are a group of intracellular multiprotein platforms that play important roles in immune systems. Benzyl isothiocyanate (BITC) is a constituent of cruciferous plants and has been confirmed to exhibit various biological activities. The modulatory effects of BITC on inflammasome-mediated interleukin (IL)-1ß expression and its regulatory mechanisms in Pseudomonas aeruginosa (P. aeruginosa) LPS/ATP-stimulated THP-1 cells was investigated. Monocytic THP-1 cells were treated with phorbol myristate acetate (PMA) to induce differentiation into macrophages. Enzyme-linked immunosorbent assays (ELISA) were performed to measure the levels of IL-1ß produced in P. aeruginosa LPS/ATP-exposed THP-1 cells. Western blotting was performed to examine the BITC modulatory mechanisms in inflammasome-mediated signaling pathways. BITC inhibited IL-1ß production in P. aeruginosa LPS/ATP-induced THP-1 cells. BITC also inhibited activation of leucine-rich repeat protein-3 (NLRP3) and caspase-1 in P. aeruginosa LPS/ATP-induced THP-1 cells. Furthermore, we show that mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) activation in P. aeruginosa LPS was attenuated by BITC. These BITC-mediated modulatory effects on IL-1ß production may have therapeutic potential for inflammasome-mediated disorders such as a nasal polyp.

Promoter Methylation of Cancer Stem Cell Surface Markers as an Epigenetic Biomarker for Prognosis of Oral Squamous Cell Carcinoma.

Growing evidence suggests that genetic and epigenetic factors, including environmental factors, contribute to the development of oral squamous cell carcinoma (OSCC). Here, we investigated the transcriptional silencing of the CD24, CD44, CD133, and CD147 genes, which are well-known cancer stem cell surface markers in various cancer types, including OSCC. We first examined the correlation between the transcriptional expression level and reactivation by 5-aza-2'-deoxycytidine (5-aza-dC) and the promoter methylation levels of the four genes in several OSCC cell lines. We observed promoter hypermethylation for the CD24, CD133, and CD147 genes at 70%, 75%, and 70%, respectively, in OSCC cell lines compared to normal oral mucosa tissues (<53%), indicating that this methylation pattern is cancer-specific, which was confirmed by bisulfite sequencing analysis. More specifically, the expression and methylation profiles of CD133 and CD147 extracted from The Cancer Genome Atlas (TCGA) database were negatively correlated, supporting their epigenetic regulation in primary OSCC tumors. The methylation status of CD133 and CD147 was associated with poor survival in patients with OSCC using the TCGA database. Our findings provide additional insight into the abnormal DNA methylation of CD133 and that CD147 could be used for the diagnosis and therapeutic treatment of patients with OSCC.

Inhibition of acute lethal pulmonary inflammation by the IDO-AhR pathway.

The lung is a prototypic organ that was evolved to reduce immunopathology during the immune response to potentially hazardous endogenous and exogenous antigens. In this study, we show that donor CD4+ T cells transiently induced expression of indoleamine 2,3-dioxygenase (IDO) in lung parenchyma in an IFN-γ-dependent manner early after allogeneic hematopoietic stem cell transplantation (HSCT). Abrogation of host IDO expression by deletion of the IDO gene or the IFN-γ gene in donor T cells or by FK506 treatment resulted in acute lethal pulmonary inflammation known as idiopathic pneumonia syndrome (IPS). Interestingly, IL-6 strongly induced IDO expression in an IFN-γ-independent manner when deacetylation of STAT3 was inhibited. Accordingly, a histone deacetylase inhibitor (HDACi) could reduce IPS in the state where IFN-γ expression was suppressed by FK506. Finally, l-kynurenine produced by lung epithelial cells and alveolar macrophages during IPS progression suppresses the inflammatory activities of lung epithelial cells and CD4+ T cells through the aryl hydrocarbon receptor pathway. Taken together, our results reveal that IDO is a critical regulator of acute pulmonary inflammation and that regulation of IDO expression by HDACi may be a therapeutic approach for IPS after HSCT.

Type I pig collagen enhances the efficacy of PEDF 34-mer peptide in a mouse model of laser-induced choroidal neovascularization.

BACKGROUND: Pigment epithelium-derived factor (PEDF)-derived 34-mer peptide (PEDF34, Asp44-Asn77) has anti-angiogenic activity but has limitations in clinical application because of an inverted bell-shaped dose-effect relationship and a short half-life. In this study, we attempted to mitigate these problems by mixing PEDF34 with type I collagen. METHODS: The anti-angiogenic activity of the PEDF34/atelocollagen mixture was evaluated by HUVEC tube formation assay and in a laser-induced choroidal neovascular (CNV) mouse model. PEDF34 and/or collagen were administrated using intravitreal injections or eye drops. CNV lesion size was quantified using FITC-dextran-perfused retinal whole mounts. Western blot analysis and inhibitor assays were used to define the action mechanisms of PEDF34 and the mixture. RESULTS: Collagen broadened the effective dose range of PEDF34 in the tube formation assay by > 250 times (from 0.2 to 50 nM). In the CNV model, five intravitreal injections of PEDF34 were required for therapeutic effect, whereas the mixture had a significant therapeutic effect following a single injection. Eye drops of the mixture showed significantly stronger CNV-suppressive effects than drops of PEDF34 alone. The anti-angiogenic activity of PEDF34 might be mediated by inhibition of ERK and JNK activation by VEGF, and collagen potentiated these effects. CONCLUSIONS: Collagen can serve as a carrier and reservoir of PEDF34. PEDF peptide/collagen mixture is easy to prepare than conventional methods for maintaining the therapeutic effect of PEDF peptide.

Cancer cell-associated cytoplasmic B7-H4 is induced by hypoxia through hypoxia-inducible factor-1α and promotes cancer cell proliferation.

Aberrant B7-H4 expression in cancer tissues serves as a novel prognostic biomarker for poor survival in patients with cancer. However, the factor(s) that induce cancer cell-associated B7-H4 remain to be fully elucidated. We herein demonstrate that hypoxia upregulates B7-H4 transcription in primary CD138(+) multiple myeloma cells and cancer cell lines. In support of this finding, analysis of the Multiple Myeloma Genomics Portal (MMGP) data set revealed a positive correlation between the mRNA expression levels of B7-H4 and the endogenous hypoxia marker carbonic anhydrogenase 9. Hypoxia-induced B7-H4 expression was detected in the cytoplasm, but not in cancer cell membranes. Chromatin immunoprecipitation analysis demonstrated binding of hypoxia-inducible factor-1α (HIF-1α) to proximal hypoxia-response element (HRE) sites within the B7-H4 promoter. Knockdown of HIF-1α and pharmacological inhibition of HIF-1α diminished B7-H4 expression. Furthermore, knockdown of cytoplasmic B7-H4 in MCF-7 decreased the S-phase cell population under hypoxia. Finally, MMGP analysis revealed a positive correlation between the transcript levels of B7-H4 and proliferation-related genes including MKI67, CCNA1, and Myc in several patients with multiple myeloma. Our results provide insight into the mechanisms underlying B7-H4 upregulation and its role in cancer cell proliferation in a hypoxic tumor microenvironment.

Caffeic acid phenethyl ester lessens disease symptoms in an experimental autoimmune uveoretinitis mouse model.

Experimental autoimmune uveoretinitis (EAU) is an autoimmune disease that models human uveitis. Caffeic acid phenethyl ester (CAPE), a phenolic compound isolated from propolis, possesses anti-inflammatory and immunomodulatory properties. CAPE demonstrates therapeutic potential in several animal disease models through its ability to inhibit NF-κB activity. To evaluate these therapeutic effects in EAU, we administered CAPE in a model of EAU that develops after immunization with interphotoreceptor retinal-binding protein (IRBP) in B10.RIII and C57BL/6 mice. Importantly, we found that CAPE lessened the severity of EAU symptoms in both mouse strains. Notably, treated mice exhibited a decrease in the ocular infiltration of immune cell populations into the retina; reduced TNF-α, IL-6, and IFN-γ serum levels: and inhibited TNF-α mRNA expression in retinal tissues. Although CAPE failed to inhibit IRBP-specific T cell proliferation, it was sufficient to suppress cytokine, chemokine, and IRBP-specific antibody production. In addition, retinal tissues isolated from CAPE-treated EAU mice revealed a decrease in NF-κB p65 and phospho-IκBα. The data identify CAPE as a potential therapeutic agent for autoimmune uveitis that acts by inhibiting cellular infiltration into the retina, reducing the levels of pro-inflammatory cytokines, chemokine, and IRBP-specific antibody and blocking NF-κB pathway activation.

Inhibitory effects of the platelet-activating factor receptor antagonists, CV-3988 and Ginkgolide B, on alkali burn-induced corneal neovascularization.

PURPOSE: Platelet-activating factor (PAF) has been found in various ocular tissues; the activity of PAF depends on the binding to its specific receptor, PAF-receptor. We investigated the therapeutic effects of PAF-receptor antagonists (CV-3988 and Ginkgolide B) on alkali burn-induced corneal neovascularization (CNV). METHODS: CNV was induced by applying a 0.2 N sodium hydroxide (3 µl, NaOH) solution directly on mice corneas. CV-3988 (1 mM/10 µl) and Ginkgolide B (1 mM/10 µl) were administered topically on the corneas three times daily for three consecutive days. CNV was evaluated under a slit-lamp microscope. Corneas were processed for histological, immunohistochemical and reverse transcription polymerase chain reaction analysis. Human umbilical vein endothelial cells were used for the migration and tube formation assay. RESULTS: Application of CV-3988 and Ginkgolide B inhibited CNV caused by alkali burn. CV-3988 and Ginkgolide B attenuated the expression of PAF-receptor mRNA. Alkali injury induced a massively increased intraocular mRNA expression of an angiogenic factor in cornea tissues, whereas these increments were attenuated by the application of CV-3988 and Ginkgolide B. CONCLUSIONS: CV-3988 and Ginkgolide B reversed opacity and neovascularization in alkali burn-induced corneas. Our findings suggest that CV-3988 and Ginkgolide B may be therapeutically useful in the treatment of CNV and inflammation.

Intratumoral heterogeneity impacts the response to anti-neu antibody therapy.

BACKGROUND: Along with de novo resistance, continued exposure to trastuzumab, an anti-human epidermal growth factor receptor 2 (HER2/neu) antibody, can lead to acquired resistance. In this study, we characterize a new anti-HER2/neu antibody resistant and metastatic mouse breast carcinoma cell line, TUBO-P2J. This cell line was developed during in vivo experiments using the antibody sensitive and non-metastatic tumor line TUBO. In addition, TUBO-P2J was used to establish an intratumoral HER2 heterogenous animal tumor model to evaluate the therapeutic effects of anti-HER2/neu antibody. METHODS: After establishing the cell line, TUBO-P2J was characterized regarding its susceptibility to anti-neu antibody and chemotherapeutics, as well as its metastatic potential in vitro and in vivo. In addition, expression profiles of metastasis related genes were also evaluated. A clinically relevant intratumoral HER2 heterogenous tumor model was established by inoculating mice with tumor cells consisting of TUBO and TUBO-P2J at a ratio of 1,000:1 or 10,000:1. Tumor growth and mouse survival were used to evaluate the therapeutic effects of anti-neu antibody. RESULTS: The TUBO-P2J cell line is a HER2/neu negative and highly metastatic variant of TUBO. This cell line was resistant to anti-neu antibody therapy, and when inoculated subcutaneously, metastasized to the lungs within 14 days. Compared to the parental TUBO cell line, TUBO-P2J displayed an epithelial-mesenchymal transition (EMT) related gene expression profile including: the loss of E-cadherin, and increased Vimentin, Snail, and Twist1 expression. In addition, TUBO-P2J exhibited increased invasion and migration activity, and was resistant to chemotherapy drugs. Finally, mixed tumor implantations experiments revealed that an increased percentage of TUBO-P2J rendered tumors less responsive to anti-neu antibody therapy. CONCLUSION: This study describes a novel model of intratumoral heterogenous metastatic breast cancer in immune competent mice that can be used to develop novel or combined immunotherapies to overcome antibody resistance.

Caffeic acid phenethyl ester inhibits the inflammatory effects of interleukin-1ß in human corneal fibroblasts.

CONTEXT: Expression of various inflammatory mediators in corneal fibroblasts contributes to corneal inflammation. OBJECTIVE: The purpose of this study was to assess the possible effects of caffeic acid phenethyl ester (CAPE) on the expression of inflammatory mediators during an inflammatory response in human corneal fibroblasts. MATERIALS AND METHODS: The levels of interleukin (IL)-6, monocyte chemotactic protein (MCP)-1, and intercellular adhesion molecule-1 (ICAM-1) from IL-1ß-exposed human corneal fibroblasts were measured with enzyme-linked immunosorbent assays (ELISA). The regulatory mechanisms of CAPE on cellular signaling pathways were examined using Western blot and electrophoretic mobility shift assays. A functional validation was carried out by evaluating the inhibitory effects of CAPE on neutrophil and monocyte migration in vitro. RESULTS: CAPE inhibited the expression of IL-6, MCP-1 and ICAM-1 induced by the pro-inflammatory cytokine IL-1ß in corneal fibroblasts. The activation of AKT and NF-κB by IL-1ß was markedly inhibited by CAPE, whereas the activity of mitogen-activated protein kinases (MAPKs) was not affected. CAPE significantly suppressed the IL-1ß-induced migration of differentiated (d)HL-60 and THP-1 cells. DISCUSSION: These anti-inflammatory effects of CAPE may be expected to inhibit the infiltration of leukocytes into the corneal stroma in vivo.

Caffeic acid phenethyl ester promotes anti-inflammatory effects by inhibiting MAPK and NF-κB signaling in activated HMC-1 human mast cells.

CONTEXT: Caffeic acid phenethyl ester (CAPE), an active component of honeybee propolis, is known to have antioxidant, anti-inflammatory, and other beneficial medicinal properties. However, the molecular mechanisms underlying its anti-allergic effects in mast cells are unknown. OBJECTIVE: The purpose of the present study was to examine whether CAPE modulates the immunoglobulin E (IgE)-mediated local allergic reaction in animals, as well as to elucidate the effects of CAPE on mast cells in vitro. MATERIALS AND METHODS: To investigate the bioactive potential of CAPE (10 or 20 µM), HMC-1 cells were stimulated with phorbol 12-myristate 13-acetate plus calcium ionophore A23187 (PMACI) for 24 h in the presence or absence of CAPE. To study the pharmacological effects of CAPE, enzyme-linked immunosorbent assays (ELISAs), RT-PCR, Western blot analysis, electrophoretic mobility shift assays (EMSAs), and fluorescence assays were used. RESULTS: CAPE (10 mg/kg) inhibited local IgE-mediated allergic reactions (0.164 versus 0.065 O.D.) in a mouse model. Additionally, CAPE (20 µM) attenuated PMACI-stimulated histamine release (3146.42 versus 2564.83 pg/ml) and the production of inflammatory cytokines, such as interleukin (IL)-1ß (4.775 versus 0.713 pg/ml, IC50 = 6.67 µM), IL-6 (4771.5 versus 449.1 pg/ml, IC50 = 5.25 µM), and IL-8 (5991.7 versus 2213.1 pg/ml, IC50 = 9.95 µM) in HMC-1 cells. In activated HMC-1 cells, pretreatment with CAPE decreased the phosphorylation of c-Jun N-terminal kinase. In addition, CAPE inhibited PMACI-induced nuclear factor (NF)-κB activation by suppressing IκBα phosphorylation and its degradation. DISCUSSION AND CONCLUSION: Our results indicated that CAPE can modulate mast cell-mediated allergic disease.

Vascular Endothelial Growth Factor Receptor 1 Targeting Fusion Polypeptides with Stimuli-Responsiveness for Anti-angiogenesis.

Genetically engineered fusion polypeptides have been investigated to introduce unique bio-functionality and improve some therapeutic activity for anti-angiogenesis. We report herein that stimuli-responsive, vascular endothelial growth factor receptor 1 (VEGFR1) targeting fusion polypeptides composed of a VEGFR1 (fms-like tyrosine kinase-1 (Flt1)) antagonist, an anti-Flt1 peptide, and a thermally responsive elastin-based polypeptide (EBP) were rationally designed at the genetic level, biosynthesized, and purified by inverse transition cycling to develop potential anti-angiogenic fusion polypeptides to treat neovascular diseases. A series of hydrophilic EBPs with different block lengths were fused with an anti-Flt1 peptide, forming anti-Flt1-EBPs, and the effect of EBP block length on their physicochemical properties was examined. While the anti-Flt1 peptide decreased phase-transition temperatures of anti-Flt1-EBPs, compared with EBP blocks, anti-Flt1-EBPs were soluble under physiological conditions. The anti-Flt1-EBPs dose dependently inhibited the binding of VEGFR1 against vascular endothelial growth factor (VEGF) as well as tube-like network formation of human umbilical vein endothelial cells under VEGF-triggered angiogenesis in vitro because of the specific binding between anti-Flt1-EBPs and VEGFR1. Furthermore, the anti-Flt1-EBPs suppressed laser-induced choroidal neovascularization in a wet age-related macular degeneration mouse model in vivo. Our results indicate that anti-Flt1-EBPs as VEGFR1-targeting fusion polypeptides have great potential for efficacious anti-angiogenesis to treat retinal-, corneal-, and choroidal neovascularization.

G-CSF-treated donor CD4+ T cells attenuate acute GVHD through a reduction in Th17 cell differentiation.

The immunoregulatory effects of granulocyte colony-stimulating factor (G-CSF) on allogeneic peripheral blood cell transplantation (PBCT) have been demonstrated to reduce acute graft-versus-host disease (GVHD). However, the underlying mechanism is still not clear. In this study, we focused on the direct effects of G-CSF on donor CD4(+) T cell responses after transplantation. We observed that lethally irradiated B6D2F1 recipient mice that are transplanted with CD4(+) T cells from G-CSF-treated B6 donors showed mild attenuations in severity and mortality compared with recipients transplanted with PBS-treated CD4(+) T cells. Notably, skin GVHD was significantly reduced, but no such reduction was observed in other organs. Although there was no difference with respect to alloreactive expansion or Foxp3(+) Treg induction, the use of G-CSF-treated CD4(+) T cells significantly reduced the numbers of IL-17-producing and RORγt-expressing cells in the secondary lymphoid organs of allogeneic recipients after transplantation compared with the use of the control cells. Finally, we found that the suppressor of cytokine signaling-3 (SOCS3) expression in G-CSF-treated donor CD4(+) T cells was much higher than that in control CD4(+) T cells. Our results demonstrate that the inhibition of Th17 cell differentiation by SOCS3 induction is associated with the immunoregulatory role of G-CSF in CD4(+) T cell-mediated acute GVHD.

Expression of galectin-9 by IFN-γ stimulated human nasal polyp fibroblasts through MAPK, PI3K, and JAK/STAT signaling pathways.

Galectin-9 exhibited potent and selective eosinophil chemoattractant activity and attracted eosinophils in vitro and in vivo. Nasal polyposis is a chronic inflammatory disease of the upper airway characterized by the marked presence of inflammatory cells, particularly eosinophils. Thus, galectin-9 may be implicated in the pathogenesis of nasal polyposis. The study was designed to investigate whether interferon-gamma (IFN-γ) can induce the augmentation of galectin-9 expression and induce the expression of galectin-9 in nasal polyps. We examined the correlation between galectin-9 expression and eosinophil infiltration in nasal polyps. In addition, we identified the signaling pathways involved in the elevation of galectin-9 expression in response to IFN-γ. Our data demonstrate that the involvement of mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3 phosphate kinase (PI3K), and Janus kinase/signal transducer and activator of transcription (JAK/STAT) may play important roles in the selective recruitment of eosinophils in nasal polyp tissues through the production of galectin-9. These findings suggest that galectin-9 expression is associated with eosinophil infiltration in polyps of patients with nasal polyposis.

Upregulation of TLR2 expression on G-CSF-mobilized peripheral blood stem cells is responsible for their rapid engraftment after allogeneic hematopoietic stem cell transplantation.

Granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood stem cells (PBSCs) are more frequently used as the cellular source in allogeneic hematopoietic stem cell transplantation (HSCT) than bone marrow stem cells (BMSCs) because they promote more rapid engraftment and immune reconstitution. However, the underlying mechanism for this is not fully understood. Here, we investigated the role of Toll-like receptor 2 (TLR2) on PBSCs in promoting rapid engraftment after allogeneic HSCT. We found that PBSCs highly expressed TLR2 in comparison to BMSCs, and TLR2 was directly induced by G-CSF signaling. Treatment with the TLR2 ligand, Pam(3)CSK(4) (PAM), more efficiently induced myeloid differentiation of PBSCs than BMSCs. Similarly, endogenous TLR2 ligands from the serum of recipients of allogeneic transplantation more rapidly stimulated myeloid differentiation of PBSCs compared with BMSCs. PAM treatment of TLR2(-/-) syngeneic recipient mice transplanted with PBSCs resulted in significantly elevated numbers of PBSC-derived myeloid cells and spleen colony formation compared with controls. Our results demonstrate that TLR2 signaling in PBSCs correlates with their ability to rapidly differentiate into myeloid cells, resulting in improved engraftment. Thus, TLR2 may be a novel target for increasing the efficiency of allogeneic HSCT by overcoming engraftment failure or delayed engraftment.

Enlightening the Immune Mechanism of the Abscopal Effect in a Murine HCC Model and Overcoming the Late Resistance With Anti-PD-L1.

PURPOSE: The establishment of a preclinical model of the abscopal effect on hepatocellular carcinoma (HCC) and evaluation of whether the hypofractionated radiation therapy (RT) multitumor Hepa1-6 mouse HCC model could be used to suppress nonradiated tumor mass was performed in this study. METHODS AND MATERIALS: Hepa1-6 mouse liver cancer cell lines were used to form tumors. Immunogenicity was analyzed using ELISpot and immune cell labeled antibody. Interferon (IFN) ß expression was confirmed through polymerase chain reaction. RESULTS: After investigation, the intratumoral transcription of type Ⅰ IFN increased by 2-fold. The antitumor immune response to Hepa 1-6 cells induced by radiation was increased. Moreover, the influx of activated CD8+ T cells was increased in nonirradiated tumors. The number of dendritic cells and activation status were evaluated by flow cytometry on the second day after irradiation. Flow cytometry revealed a significantly increased dendritic cell population expressing the CD11c molecule in tumor-draining lymph nodes. Furthermore, because irradiation leads to adaptation of immune resistance of tumor cells against RT, we sought to elucidate a potent tool to overcome the resistance and confirm the ability of PD-L1 antibody to survive late RT resistance. CONCLUSIONS: The immunologic mechanism of the abscopal effect was revealed and the application of PD-L1 inhibitor successfully performed as a breakthrough in late RT resistance in the Hepa1-6 tumor model.