Intraperitoneal Macrophages Research Articles

Invariant Natural Killer T Cells Modulate the Peritoneal Macrophage Response to Polymicrobial Sepsis

IntroductionA dysregulated immune system is a major driver of the mortality and long-term morbidity from sepsis. With respect to macrophages, it has been shown that phenotypic changes are critical to effector function in response to acute infections, including intra-abdominal sepsis. Invariant natural killer T cells (iNKT cells) have emerged as potential central regulators of the immune response to a variety of infectious insults. Specifically, various iNKT cell:macrophage interactions have been noted across a spectrum of diseases, including acute events such as sepsis. However, the potential for iNKT cells to affect peritoneal macrophages during an abdominal septic event is as yet unknown. MethodsCecal ligation and puncture (CLP) was performed in both wild type (WT) and invariant natural killer T cell knockout (iNKT−/−) mice. 24 h following CLP or sham operation, peritoneal macrophages were collected for analysis. Analysis of macrophage phenotype and function was undertaken to include analysis of bactericidal activity and cytokine or superoxide production. ResultsWithin iNKT−/− mice, a greater degree of intraperitoneal macrophages in response to the sepsis was noted. Compared to WT mice, within iNKT−/− mice, CLP did induce an increase in CD86+ and CD206+, but no difference in CD11b+. Unlike WT mice, intra-abdominal sepsis within iNKT−/− mice induced an increase in Ly6C-int (5.2% versus 14.9%; P < 0.05) and a decrease in Ly6C-high on peritoneal macrophages. Unlike phagocytosis, iNKT cells did not affect macrophage bactericidal activity. Although iNKT cells did not affect interleukin-6 production, iNKT cells did affect IL-10 production and both nitrite and superoxide production from peritoneal macrophages. ConclusionsThe observations indicate that iNKT cells affect specific phenotypic and functional aspects of peritoneal macrophages during polymicrobial sepsis. Given that pharmacologic agents that affect iNKT cell functioning are currently in clinical trial, these findings may have the potential for translation to critically ill surgical patients with abdominal sepsis.

Functional remodeling of intraperitoneal macrophages by oncolytic adenovirus restores anti-tumor immunity for peritoneal metastasis of gastric cancer

Intraperitoneal tumor-associated macrophages (TAMs) are involved in evading anti-tumor immunity and promoting the peritoneal metastasis (PM) of gastric cancer (GC). Oncolytic viruses are known to induce the activation of host anti-tumor immunity in addition to tumor lysis. This study investigated whether a wild-type p53-loading telomerase-specific oncolytic adenovirus (OBP-702) could elicit the remodeling of intraperitoneal macrophages and enhance the efficacy of immune therapy. Increased numbers of CD163 TAMs and few CD8+ lymphocytes were immunohistochemically observed in clinical samples with PM, which suggested that TAMs were associated with the suppression of anti-tumor immunity. OBP-702 induced immunogenic cell death and upregulated PD-L1 expression in human and murine GC cell lines. Intraperitoneal administration of OBP-702 increased recruitment of CD8+ lymphocytes into the PM via the functional remodeling of intraperitoneal macrophages from TAM towards a pro-inflammatory phenotype, resulting in significantly suppressed tumor growth for the in vivo model. Furthermore, the combination of intraperitoneal OBP-702 with anti-PD-1 Antibody enhanced anti-tumor immunity and prolonged the survival of mice bearing PM. Intraperitoneal immunotherapy using OBP-702 restores anti-tumor immunity via the remodeling of intraperitoneal macrophages in addition to direct tumor lysis and cooperates with immune checkpoint inhibitors to suppress PM in GC.

A novel fatty acid analogue triggers CD36–GPR120 interaction and exerts anti-inflammatory action in endotoxemia

Inflammation is a mediator of a number of chronic pathologies. We synthesized the diethyl (9Z,12Z)-octadeca-9,12-dien-1-ylphosphonate, called NKS3, which decreased lipopolysaccharide (LPS)-induced mRNA upregulation of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) not only in primary intraperitoneal and lung alveolar macrophages, but also in freshly isolated mice lung slices. The in-silico studies suggested that NKS3, being CD36 agonist, will bind to GPR120. Co-immunoprecipitation and proximity ligation assays demonstrated that NKS3 induced protein–protein interaction of CD36 with GPR120in RAW 264.7 macrophage cell line. Furthermore, NKS3, via GPR120, decreased LPS-induced activation of TAB1/TAK1/JNK pathway and the LPS-induced mRNA expression of inflammatory markers in RAW 264.7 cells. In the acute lung injury model, NKS3 decreased lung fibrosis and inflammatory cytokines (IL-1β, IL-6 and TNF-α) and nitric oxide (NO) production in broncho-alveolar lavage fluid. NKS3 exerted a protective effect on LPS-induced remodeling of kidney and liver, and reduced circulating IL-1β, IL-6 and TNF-α concentrations. In a septic shock model, NKS3 gavage decreased significantly the LPS-induced mortality in mice. In the last, NKS3 decreased neuroinflammation in diet-induced obese mice. Altogether, these results suggest that NKS3 is a novel anti-inflammatory agent that could be used, in the future, for the treatment of inflammation-associated pathologies.

The NLRP3 Inflammasome-Independent IL-18 Elevation Induced by Candida Albicans Cell Wall

Objective: IL-18 has a significant role in host defense and pathogenesis of many inflammatory diseases. IL-18 production initiates if a particular PRR of innate immune cell binds specific PAMP, including O-linked mannan, a Candida albicans cell wall component. The binding of these PAMPs by TLR4 activates the intracellular signal pathway and activates NFkB to induce the production of pro-IL-18. Pro IL-18 undergoes breakdown to IL-18 active by the most common enzyme, caspase-1. Caspase-1 is the result of NLRP3 inflammasome activation. This study aimed to prove that the Candida albicans cell wall can induce IL-18 production and explore the role of NLRP3 inflammasome in that process. Methods: The Male Wistar rats were injected with 8 mg/kg BW/day and 16 mg/kg BW C. albicans cell wall intraperitoneally on 5 consecutive days in 2 periods with 23 days intervals between periods. Rats were sacrificed 24 h after the end of treatment. Expressions of NLRP3 inflammasome of intraperitoneal macrophages were measured by flow cytometry, and the level of IL-18 in blood plasma was measured with the ELISA technique. Results: IL-18 significantly increased in groups injected with 16 mg/kg BW/day but not those with 8 mg/kg BW/day. The expression of NLRP3 inflammasome was significantly increased in the group injected with 8 mg/kg BW/days C. albicans cell wall but not in the group injected with 16 mg/kg BW/days. Regression analysis showed that the increasing level of IL-18 was dependent on the C albicans cell wall dose but independent of the NLRP3inflamassome expression. The NLRP3-inflammasome expression did not depend on C albicans cell wall dose. Conclusions: C. albicans’ cell wall can increase the IL-18 plasma blood level, and the production of IL-18 is independent of NLRP3-inflammasome activation. HIGHLIGHTS C. albicans cell wall induces IL-18 plasma levels that can cause inflammatory diseases C. albicans cell wall induces NLRP3-inflammasome in small doses but not in high dose The elevation of IL-18 is independent of the expression of NLRP3-inflammasome on the macrophage GRAPHICAL ABSTRACT

Toll-like receptor 4 deficiency in mice impairs venous thrombus resolution.

Objective: Toll-like receptor 4 (TLR4) is crucial to the development of sterile inflammatory responses. The deep venous thrombosis resolution (DVT) is similar to sterile inflammation, so we hypothesize that TLR4 is involved. Methods and Results: We evaluated the effects of TLR4 deficiency on thrombus lysis in vivo, and explored the mechanisms in vitro. DVT mouse model was established by inferior vena cava (IVC) ligation. After the IVC ligation (1, 3, and 7d), the mice were euthanized to collect the venous thrombus. The Tlr4-/- mice had significantly elevated weight/length ratios of thrombi at 3 and 7d and increased collagen content at 3d after IVC ligation, in addition to significantly lesser intrathrombus infiltration of neutrophils and macrophages, lower monocyte chemoattractant protein-1 (MCP-1) and matrix metalloproteinase-9 (MMP-9) expression in thrombus tissue sections and homogenates, and lower pro-MMP-9 activity at 3d after IVC ligation than wild-type mice. After 7days of IVC ligation, VEGF, IFNβ, and MCP-5 protein expression were decreased in venous thrombus from Tlr4-/- mice. 2ml of 3% thioglycolate was injected intraperitoneally and peritoneal exudate was collected 3days later from Tlr4-/- and wild type mice respectively. The intraperitoneal macrophages were isolated from adherent culture after centrifugation. Lipopolysaccharide (LPS) can activate TLR4/NF-κB signalling pathway in a concentration-dependent manner, initiated p65 nuclear translocation, IκBα phosphorylation and degradation, MMP-9 and MCP-1 transcription in WT intraperitoneal macrophages but not in Tlr4-/- intraperitoneal macrophages. Conclusion: TLR4 is involved in venous thrombosis resolution through NF-κB pathway. Loss of TLR4 in mice impairs the process.

Sulforaphane Inhibits Foam Cell Formation and Atherosclerosis via Mechanisms Involving the Modulation of Macrophage Cholesterol Transport and the Related Phenotype

Sulforaphane (SFN), an isothiocyanate, is one of the major dietary phytochemicals found in cruciferous vegetables. Many studies suggest that SFN can protect against cancer and cardiometabolic diseases. Despite the proposed systemic and local vascular protective mechanisms, SFN’s potential to inhibit atherogenesis by targeting macrophages remains unknown. In this study, in high fat diet fed ApoE-deficient (ApoE−/−) mice, oral SFN treatment improved dyslipidemia and inhibited atherosclerotic plaque formation and the unstable phenotype, as demonstrated by reductions in the lesion areas in both the aortic sinus and whole aorta, percentages of necrotic cores, vascular macrophage infiltration and reactive oxygen species (ROS) generation. In THP-1-derived macrophages, preadministration SFN alleviated oxidized low-density lipoprotein (ox-LDL)-induced lipid accumulation, oxidative stress and mitochondrial injury. Moreover, a functional study revealed that peritoneal macrophages isolated from SFN-treated mice exhibited attenuated cholesterol influx and enhanced apolipoprotein A-I (apoA-I)- and high-density lipoprotein (HDL)-mediated cholesterol efflux. Mechanistic analysis revealed that SFN supplementation induced both intralesional and intraperitoneal macrophage phenotypic switching toward high expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and ATP-binding cassette subfamily A/G member 1 (ABCA1/G1) and low expression of peroxisome proliferator-activated receptor γ (PPARγ) and cluster of differentiation 36 (CD36), which was further validated by the aortic protein expression. These results suggest that the regulation of macrophages’ cholesterol transport and accumulation may be mainly responsible for SFN’s potential atheroprotective properties, and the regulatory mechanisms might involve upregulating ABCA1/G1 and downregulating CD36 via the modulation of PPARγ and Nrf2.

Cancer cell genotype associated tumor immune microenvironment exhibits differential response to therapeutic STING pathway activation in high-grade serous ovarian cancer

BackgroundHigh-grade serous ovarian carcinoma (HGSC) is the most lethal gynecologic malignancy characterized by resistance to chemotherapy and high rates of recurrence. HGSC tumors display a high prevalence of tumor suppressor...

Isolation and chemical characterization of antifungal, antioxidant, and anti-inflammatory compounds from Centrosema coriaceum using GC/MS, UFLC-QTOF-MS, and FACE.

In recent years, natural products with biological activities have been increasingly researched. The elucidation of phytoconstituents is necessary for the development of drugs as a natural alternative for the treatment of various diseases. The work aimed to evaluate in vitro and insilico bioactivities of hexane (CCHE) and methanol (CCME) fractions of ethanolic extract from Centrosema coriaceum Benth (Fabaceae) leaves and elucidate their phytoconstituents. CCHE and CCME showed antifungal activity for Candida glabrata (MIC of 1000 µg/mL) with fungistatic effect and action in cell envelope by sorbitol and ergosterol assays. CCHE and CCME presented promising antioxidant activity against the DPPH radical with IC50 of 13.61 ± 0.50 and 6.31 ± 0.40 µg/mL, respectively, and relative antioxidant activity (RAA%) of 45.77 ± 3.61/ 28.53 ± 2.25 % for CCHE and 82.18 ± 2.25/ 51.99 ± 3.23 % for CCME when compared to rutin and quercetin, respectively. Moreover, these fractions demonstrated promising results for the inhibition of lipid peroxidation by β-carotene/linoleic acid assay. For anti-inflammatory and cytotoxicity activities, CCHE and CCME significantly inhibited the production of nitric oxide and TNF-α, without toxicity on murine intraperitoneal macrophages, respectively. Esters, alkanes, steroids, tocopherols, and terpenes were identified in CCHE by GC/MS. Flavonoids, phenolic acids, and disaccharides were detected in CCME by UFLC-QTOF-MS and FACE. Furthermore, rutin was purified from CCME. In silico predictions evidenced that compounds present in both fractions have high affinity to the fungal membrane besides antioxidant and anti-inflammatory activities. Based on these observations, CCHE and CCME have a noteworthy potential for the design of novel antifungal and anti-inflammatory agents that should be explored in future studies.

Intraperitoneal administration of PLGA nanoparticles could deliver the cargo to tumor-associated macrophages with less spreading peritoneal macrophages in the treatment of peritoneal carcinomatosis

The survival time of patients with peritoneal metastasis is limited despite all treatments. Recent studies revealed that tumor-associated macrophages (TAMs) are educated in the tumor microenvironment for tumor growth and progression. The use of nanoparticles is considered an opportunity to deliver the therapeutics for depletion or re-education of these TAMs. In this study, it was planned to answer whether Poly(lactic-co-glycolic acid) (PLGA) nanoparticles applied to the peritoneum could be successful in delivering drugs to TAMs in peritoneal metastasis. For this purpose, Nile red loaded PLGA nanoparticles were prepared and characterized. Nil-PLGA NPs and nil red solution were injected intraperitoneally to mice model of CT-26 colon adenocarcinoma peritoneal metastasis, and nile red labeled macrophages were evaluated with the flow cytometer. The average particle size and zeta potential of nanoparticles were found as 238.4 ± 22.9 nm and −1.38 ± 1.35 mV, respectively. Labeled macrophages percent in the tumor was not found statistically different. On the other hand, after intraperitoneal administration of nil red solution, there was a very high nile red transfer to macrophages within the peritoneum. This widespread transfer was prevented by the application of nile red-loaded nanoparticles. This result shows that intraperitoneal application of PLGA nanoparticles could be an opportunity for drug delivery to TAMs with less damage to intraperitoneal macrophages.

Deletion of GPR21 improves glucose homeostasis and inhibits the CCL2-CCR2 axis by divergent mechanisms

IntroductionA potential role for the orphan G protein-coupled receptor, GPR21, in linking immune cell infiltration into tissues and obesity-induced insulin resistance has been proposed, although limited studies in mice are...

Sphingosine 1-Phosphate (S1P) in the Peritoneal Fluid Skews M2 Macrophage and Contributes to the Development of Endometriosis.

Sphingosine 1-phosphate (S1P), an inflammatory mediator, is abundantly contained in red blood cells and platelets. We hypothesized that the S1P concentration in the peritoneal cavity would increase especially during the menstrual phase due to the reflux of menstrual blood, and investigated the S1P concentration in the human peritoneal fluid (PF) from 14 non-endometriosis and 19 endometriosis patients. Although the relatively small number of samples requires caution in interpreting the results, S1P concentration in the PF during the menstrual phase was predominantly increased compared to the non-menstrual phase, regardless of the presence or absence of endometriosis. During the non-menstrual phase, patients with endometriosis showed a significant increase in S1P concentration compared to controls. In vitro experiments using human intra-peritoneal macrophages (MΦ) showed that S1P stimulation biased them toward an M2MΦ-dominant condition and increased the expression of IL-6 and COX-2. An in vivo study showed that administration of S1P increased the size of the endometriotic-like lesion in a mouse model of endometriosis.

HYBID derived from tumor cells and tumor-associated macrophages contribute to the glioblastoma growth

Glioblastoma is the most malignant tumor of the brain associated with poor prognosis and outcome, and hence there is an urgent need to develop novel treatments for glioblastoma. In this study, we focused on hyaluronan binding protein (HYBID, as known as CEMIP/KIAA1199), a protein involved in hyaluronan depolymerization in chondrocytes and synoviocytes. We previously reported that Hybid-deficient (KO) mice show accumulation of hyaluronan in the brain, and memory impairment. To elucidate the role of HYBID in glioblastoma pathogenesis, we knocked down HYBID in human glioblastoma cells using siRNAs and developed a murine orthotopic xenograft model in the Hybid KO mice. Downregulation of HYBID in glioblastoma cells resulted in inhibition of cell proliferation and migration, and increased cell death. The growth of glioblastoma cells implanted in the mouse brain was suppressed in Hybid KO mice compared to that in the wild-type mice. Interestingly, infiltration of macrophages in the glioblastoma tissue was decreased in Hybid KO mice. Using intraperitoneal macrophages derived from Hybid KO mice and glioma cell supernatants, we examined the role of HYBID in macrophages in the tumor environment. We showed that HYBID contributes to macrophage migration and the release of pro-tumor factors. Moreover, we revealed that HYBID can be a poor prognostic factor in glioma patients by bioinformatics approaches. Our study provides data to support that HYBID expressed by both glioblastoma cells and tumor-associated macrophages may contribute to glioblastoma progression and suggests that HYBID may be a potential target for therapy that focuses on the tumor microenvironment of glioblastoma.

Cancer-derived Exosomes Activate Immune Surveillance and Suppress Peritoneal Metastasis of Murine Colonic Cancer.

Colonic cancer is associated with a low incidence of peritoneal metastasis compared with gastric cancer; however, the reason for this remains unclear. In this study, a model of peritoneal dissemination using the CT26 murine colon cancer cell line was used to analyze the physiological roles of cancer-derived exosomes. Exosomes were collected from the supernatant of CT26 cell culture by ultracentrifugation. The number of peritoneal disseminations in two mouse models of colonic cancer pre-administered exosomes or phosphate-buffered saline were compared. Cancer-derived exosomes suppressed peritoneal dissemination compared to phosphate-buffered saline. After administration of exosomes, the number of intraperitoneal macrophages and the expression of inducible nitric oxide synthase increased. Furthermore, cancer-derived exosomes increased activated natural killer cells and interferon-γ expression. Tumor-derived exosomes from colonic cancer may suppress peritoneal metastasis via an immunological mechanism.

Hyperthermic intraperitoneal chemotherapy enhances antitumor effects on ovarian cancer through immune-mediated cancer stem cell targeting

Purpose We aimed to determine the effects and possible mechanisms of hyperthermic intraperitoneal chemotherapy (HIPEC) in targeting ovarian cancer stem-like cells (CSCs). Methods Murine ovarian cancer cell lines presenting CSC surface markers were grown intraperitoneally in both immunocompetent and immunodeficient mice, which were then treated by intraperitoneal hyperthermia with the chemotherapeutic agents: paclitaxel and cisplatin. Tumor growth was measured by non-invasive luminescent imaging. Intraperitoneal immune cells, such as CD4+, CD8+ T cells, macrophages, and dendritic cells, were evaluated through flow cytometry analysis. Results Combined hyperthermia and chemotherapy exhibited an efficient therapeutic effect in the immunocompetent mice. However, a similar effect was not observed in the immunodeficient mice. Intraperitoneal hyperthermia increased the number of Intraperitoneal macrophages and dendritic cells that were lost due to chemotherapy. Compared with ovarian cancer bulk cells, CSCs were more susceptible to phagocytosis by macrophages. Conclusion We demonstrated that the superior therapeutic efficacy and reduced proportion of CSCs associated with intraperitoneal hyperthermic chemotherapy were immune-related. Hyperthermia recruits the phagocytes that target surviving CSCs after chemotherapy. These results provide a novel mechanism for the efficacy of HIPEC in treating ovarian cancer.

Effects of Lonicera japonica Flower Bud Extract on Citrobacter rodentium-Induced Digestive Tract Infection.

Background: Although antibiotic therapy is currently a gold standard for bacterial infections, it is not used for severe diseases like enterohemorrhagic Escherichia coli, in which the Shiga toxin is overproduced by antibiotic action. The Lonicera japonica flower bud (LJF) is an herbal component used against purulent diseases in traditional Japanese and Chinese medicine. We investigated the effects of LJF extract (LJFE) on Citrobacter rodentium-induced digestive tract infection in a mouse model. Methods: Citrobacter rodentium and LJFE were orally administered to C57BL/6 mice. The survival rate and bacterial colonization in the large intestine, mesenteric lymph node, and blood of mice were evaluated. Cytokines secreted from intraperitoneal macrophages of LJFE-treated mice were measured using ELISA. Moreover, the phagocytic activity of intraperitoneal macrophages against Citrobacter rodentium was compared between LJFE- or chlorogenic acid (CGA)-treated mice. Results: LJFE significantly increased the survival rate and decreased Citrobacter rodentium colonization in mice. Moreover, the values of tumor necrosis factor-α, interleukin-1β, and interferon-γ secreted from macrophages were increased following LJFE treatment. While macrophages of LJFE-treated mice showed a significant phagocytic activity, macrophages of CGA-treated mice only showed a phagocytic tendency. Conclusions: LJF may be useful for treating Citrobacter rodentium-induced digestive tract infection.

Immune Activity of Polysaccharide Fractions Isolated from Korean Red Ginseng

Korean red ginseng (KRG)’s pharmacological efficacy and popular immunomodulatory effects have already been proven in many studies; however, the component of KRG that is effective in immune activity has not been studied before. Therefore, this study extracted and separated KRG for an immune activity comparison. In the water fraction obtained by extracting KRG powder with water, a red ginseng neutral polysaccharide (RGNP) fraction and a red ginseng acidic polysaccharide (RGAP) fraction were obtained. Each fraction was orally administered for 10 days to mice with reduced immunity, and the number of IgM antibody-forming cells (AFCs) in splenocytes was measured to compare the immune activity of the water fractions. The results showed that the RGAP fraction has the greatest number of AFCs. To set the optimal dose of the RGAP fraction, which had the highest immune activity, the AFCs, macrophage activity, and splenocyte subtype in the mice were analyzed. As a result, the number of AFCs was significantly increased in the RGAP fraction compared to RGNP. The intraperitoneal macrophage phagocytosis activity and the number of T cells, B cells, and macrophages in the spleen increased significantly. It can, therefore, be confirmed that immune activity increases by a fraction containing higher RGAP content, and we hypothesize that RGAP activates immune activity.

Doxorubicin modulated clock genes and cytokines in macrophages extracted from tumor-bearing mice

ABSTRACT Circadian rhythm is essential for cellular regulation of physiological, metabolic, and immune functions. Perturbations of circadian rhythms have been correlated with increased susceptibility to cancer and poor prognosis in the cancer treatment. Our aim is to investigate the role of doxorubicin (DOX) treatment on clock genes expression and inflammation in intraperitoneal macrophages and the antitumoral response. Methods: Macrophages were extracted from intraperitoneal cavity of mice without or with Lewis lung carcinoma (LLC) and treated with DOX totaling four groups (CTL, LLC, LLC+DOX and DOX) and analyzes of clock genes in six time points (ZT02, ZT06, ZT10, ZT14, ZT18 AND ZT22). Intraperitoneal macrophages cell culture was stimulated with LPS and DOX and clock genes and inflammatory profile were analyzed. In tumor were analyzed macrophages markers. Results: The expression of F4/80 (ZT22) and CD11c (ZT06) tumor tissue was significantly differed between LLC and LCC+DOX groups. In the intraperitoneal macrophages, DOX increased Clock (ZT10), Rev-Erbα (ZT18 and ZT22) and Per2 expressions (ZT18); in the LLC+DOX group was increased Bmal1 (ZT10), Per2 (ZT18) and NF-kB (ZT22) expressions; IL-6 expression increased in the LCC group (ZT02). In intraperitoneal macrophages cell culture stimulated with DOX and LPS after 24 h decreased Clock and Per1. DOX causes depression after 6 and 24 h in TNF-α content and Per2 gene expression after 24 h IL-1β expression was reduced also. Conclusion: DOX treatment in vivo disrupted cytokine and clock genes expression in intraperitoneal macrophages suppressing immune response. Moreover, macrophages cultured with DOX had decreased expression of LPS-stimulated inflammatory cytokines.

Lipidoid-siRNA Nanoparticle-Mediated IL-1β Gene Silencing for Systemic Arthritis Therapy in a Mouse Model

Interleukin-1 beta (IL-1β) plays a central role in the induction of rheumatoid arthritis (RA). In the present study, we demonstrated that lipidoid-polymer hybrid nanoparticle (FS14-NP) can efficiently deliver siRNA against IL-1β (siIL-1β) to macrophages and effectively suppress the pathogenesis of experimental arthritis induced by collagen antibody (CAIA mice). FS14-NP/siIL-1β achieved approximately 70% and 90% gene-silencing efficiency in the RAW 264.7 cell line and intraperitoneal macrophages, respectively. Intravenous administration of FS14-NP/siRNA led to rapid accumulation of siRNA in macrophages within the arthritic joints. Furthermore, FS14-NP/siIL-1β treatment lowered the expression of pro-inflammatory cytokines in arthritic joints and dramatically attenuated ankle swelling, bone erosion, and cartilage destruction. These results demonstrate that FS14-NP/siIL-1β may represent an effective therapy for systemic arthritis and other inflammatory disorders.

Antineoplastic, Bio-Chemical, Cytotoxic and Antimicrobial Investigation on Synthesized Schiff Base Co(II) Ion Complex

Antibiotic resistance has been growing at an alarming rate and consequently the activity of antibiotics has dropped dramatically day by day. Metal complex [Co (SB) (SCN)] (where, SB = 2-[(6-Amino-hexylimino)-methyl] phenol) have been reported for the purpose of searching new antimicrobial agents. The Schiff base and it’s transition metal complex was characterized by means of several physiochemical and spectroscopic methods. Several biomedical toxicological properties of the complex has been determined by monitoring the parameters cell growth inhibition, survival time of tumour mice, time-body relation, causing of intraperitoneal cells and macrophages, alkaline phosphatase activity, haematological effect and biopsy of tumour. The synthesized Schiff base Co (II) complex was found to have anticancer and cytotoxic function.

Abstract 5011: Tumor associated macrophages promote malignant phenotypes of disseminated human gastric cancer cells in intraperitoneal cancer immune microenvironment

Abstract Gastric cancer is the third leading cause of cancer-related death, and peritoneal dissemination is one of the most frequent site of recurrence. Although the role of tumor microenvironment is recognized, it is still unclear how intraperitoneal cancer-immune microenvironment contributes to peritoneal metastasis. Thus, we investigated the interaction between intraperitoneal cancer and immune cells, especially focusing on tumor-associated macrophages (TAM) in the peritoneal cavity. The peritoneal wash from gastric cancer patients was subjected to conventional cytology, flow cytometry, and immuno-fluorescent assay using antibodies against CD45 (leukocytes), CD14 (monocytes), CD80/163 (M1/M2 macrophages, respectively), in combination with genetically engineered cancer-imaging viral agent ‘TelomeScan’ which specifically expresses GFP in telomerase-positive cells. In cytology-positive samples, CD163-positive macrophages could be detected in approximately 70% of intraperitoneal macrophages with TelomeScan-positive cancer cells, while cytology negative samples contained few CD163-positive macrophages. In addition, peripheral blood mononuclear cells (PBMCs) from healthy volunteers were induced to differentiate into CD163-positive M2 macrophages (TAM-like macrophages), and co-cultured with gastric cancer cells to examine the effect on their malignant phenotype such as migration and invasion. We found that PBMCs-derived CD163-positive M2 macrophages significantly potentiated the ability of migration and invasion in gastric cancer cells. In case of existence of free cancer cells in peritoneal cavity, intraperitoneal macrophages appeared to differentiate into TAM and they potentially accelerate malignant phenotypes of gastric cancer cells. These results suggested that intraperitoneal cancer-immune microenvironment may play an important role to promote peritoneal disseminations in gastric cancer. Citation Format: Shuichi Sakamoto, Shunsuke Kagawa, Kazuya Kuwada, Atene Ito, Tetsuya Kagawa, Satoru Kikuchi, Shinji Kuroda, Ryuichi Yoshida, Hiroshi Tazawa, Toshiyoshi Fujiwara. Tumor associated macrophages promote malignant phenotypes of disseminated human gastric cancer cells in intraperitoneal cancer immune microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5011. doi:10.1158/1538-7445.AM2017-5011