In vitro activation and maturation of human mononuclear phagocytes by stimulation with liposomes coated with a neoglycolipid containing α1-3, α1-6-mannotriose.

In this study, we assessed the potential of liposomes coated with a neoglycolipid containing α1-3,α1-6-mannotriose residues (Man3-DPPE; Manα1-6(Manα1-3)Manitol-DPPE) for in vitro activation and maturation of human mononuclear phagocytes. In response to treatment with Man3-DPPE-coated liposomes (Man3-OMLs), PMA-stimulated human THP-1 cells showed enhanced expression of CD40, CD80 and HLA-DR and secreted significant levels of IL-12p40. Among various linkages of Man2-DPPE-coated liposomes, only liposomes coated with Manα1-6Manitol-DPPE (α1-6Man2-DPPE) induced these cellular responses similarly to Man3-OML treatment. Liposomes coated with Manα1-6(Manα1-3)Manα1-6(Manα1-3)Manitol-DPPE (Man5-DPPE) failed to activate the cells. These results suggest that an unsubstituted α1-6Man branch bound to a mannitol unit at the reducing end in Man3-DPPE is required for in vitro activation of human mononuclear phagocytes. Man3-OML-induced IL-12p40 production was not inhibited by BAY11-7082, an inhibitor of the MyD88-dependent signaling network, suggesting that TLRs are not involved in activation of human mononuclear phagocytes by Man3-OMLs. Stimulation of inflammatory monocytes or monocyte-derived dendritic cells (moDCs) with Man3-OMLs also induced enhanced expression of co-stimulatory molecules, HLA-DR, and CCR7, and IL-12p40 production from both types of cells. In response to Man3-OML treatment, moDCs but not inflammatory monocytes produced bioactive IL-12p70, which was enhanced by CD40 ligation. Thus, Man3-OMLs can activate naïve human mononuclear phagocytes and lead human moDCs to a fully matured status in vitro to elicit CTLs and a Th1 response without addition of inflammatory cytokines or TLR agonists.

Decabromodiphenyl Ether (DecaBDE) in Electrical and Electronic Equipment in Japan: Stock, Emission, and Substitution Evaluation.

DecaBDE has been widely used as flame retardant in electrical and electronic equipment (EEE). It has recently been listed in Annex A of the Stockholm Convention. The time series flow, stock, and emission of DecaBDE in EEE in Japan were quantified. On this basis, a risk/risk trade-off analysis of substituting DecaBDE with triphenyl phosphate (TPhP) that is one possible phosphorus-based alternative was conducted. The stock of DecaBDE reached a maximum of ∼42 000 t in 1995. Even though the demand flow was negligible in 2030, the stock was modeled to be still ∼470 t. The outflow of DecaBDE, from the use phase to the disposal phase, peaked at ∼4500 t/yr. in 2001. The DecaBDE emission to atmosphere was mainly derived from the production phase before 1990. The use phase became the largest contributor to the total emission from 1995 to 2000. Whereas the disposal phase dominated the total emission from 2000 onward. In the substitution analysis, a trade-off between human and ecological health effect was revealed in case of replacing DecaBDE with TPhP. This study attempted to give an overall picture of DecaBDE application at national level providing insights into relevant environmental policy making.

SIGNR1-mediated phagocytosis, but not SIGNR1-mediated endocytosis or cell adhesion, suppresses LPS-induced secretion of IL-6 from murine macrophages.

C-type lectin receptors (CLRs) serve as phagocytosis receptors for pathogens and also function as adhesion molecules and in the recognition and endocytosis of glycosylated self-antigens. In the present study, we demonstrated that phagocytosis mediated by a mouse mannose-binding CLR, SIGNR1 significantly suppressed the LPS-induced secretion of the specific pro-inflammatory cytokines from the resident peritoneal macrophages and the mouse macrophage-like cells that express SIGNR1 (RAW-SIGNR1). LPS-induced secretion of IL-6 from peritoneal macrophages suppressed in response to uptake of oligomannose-coated liposomes (OMLs), and the suppression was partly inhibited by treatment with an anti-SIGNR1 antibody. LPS-induced secretion of IL-6 from RAW-SIGNR1 cells was also clearly inhibited by treatment of the cells with OMLs >0.4µm in diameter, but treatment with OMLs <0.4µm in diameter did not affect the IL-6 secretion. In contrast, LPS-induced TNF-α secretion from the cells was not affected on treatment of the cells with OMLs. Suppression of the IL-6 secretion was not observed following treatment with oligomannose-containing soluble polymers or when cells were bound to an oligomannose-coated solid phase. Phagocytosis of oligomannose-coated liposomes did not interfere with the transcription of IL-6 mRNA, but did affect IL-6 mRNA stability, leading to suppression of IL-6 secretion. Interestingly, treatment of the cells with Ly290042, a PI3 kinase inhibitor, partly blocked the suppression of LPS-induced secretion of IL-6 by OML. Thus, we conclude that SIGNR1-mediated phagocytosis but not SIGNR1-mediated endocytosis and cell adhesion, suppresses the TLR4-mediated production of specific proinflammatory cytokines via PI3 kinase signaling.

C-type lectin receptor SIGNR1 expressed on peritoneal phagocytic cells with an immature dendritic cell-like phenotype is involved in uptake of oligomannose-coated liposomes and subsequent cell maturation.

The mannose-binding C-type lectin receptor SIGNR1 appears to be a structural and functional murine homologue of human DC-SIGN, but expression of SIGNR1 and its function in induction of immune responses in dendritic cell (DC) lineages remains unclear. In this study, we demonstrated expression and function of SIGNR1 on mouse peritoneal phagocytic cells with an immature DC-like phenotype. Analysis of these cells with a series of cell lineage markers indicated that CD11b(+)F4/80(-) phagocytic cells expressed costimulatory molecules, the DC marker CD83, and MHC class II, suggesting an immature DC-like phenotype. These immature peritoneal DC-like cells expressed low levels of SIGNR1, in addition to another mannose-binding C-type lectin, CD206. The immature peritoneal DC-like cells ingested oligomannose- or Lewis antigen-coated liposomes in vitro through SIGNR1. Following in vitro uptake of oligomannose-coated liposomes, SIGNR1, but not CD206, disappeared rapidly from the surface of the cells. In response to in vitro uptake of OMLs, the peritoneal DC-like cells matured with increasing expression of CD11c, CD86, and MHC class II. Thus, low levels of SIGNR1 expressed on mouse peritoneal phagocytic cells with an immature DC-like phenotype are primarily involved in uptake of mannose- or fucose-decorated particles, and this uptake leads to cell maturation.

Plasmodium berghei circumsporozoite protein encapsulated in oligomannose-coated liposomes confers protection against sporozoite infection in mice.

BACKGROUND: The design and development of an effective malaria vaccine against the pre-erythrocytic and erythrocytic-stages of infection present a great challenge. METHODS: In the present study, protective efficacy of oligomannose-coated liposome (OML)-entrapped merozoite and sporozoite antigens against Plasmodium berghei challenge infection in BALB/c mice was evaluated. RESULTS: Subcutaneous immunization with truncated merozoite surface protein 1 entrapped with OML (OML-PbMSP1) prolonged survival, but failed to protect the mice from erythrocytic-stage infection, despite the antigen-specific antibody responses induced by the immunization regimen. In contrast, immunization with circumsporozoite protein entrapped with OML (OML-PbCSP) elicited antigen-specific humoral and cellular responses, which correlated with substantial protection against sporozoite challenge infections. CONCLUSIONS: The current results represent the use of an oligomannose-coated liposome-based vaccine against pre-erythrocytic and erythrocytic stages malaria infection. This approach may offer a new vaccination strategy against malaria infection.

Preferences for uptake of carbohydrate-coated liposomes by C-type lectin receptors as antigen-uptake receptors.

We evaluated the carbohydrate preferences of the C-type lectin receptors (CLRs) SIGNR1, SIGNR3, and Langerin as pathogen-uptake receptors based on uptake of liposomes consisting of cholesterol, DPPC, and various neoglycolipids at molar ratios of 10:10:1 and 10:7:4, respectively, using non-phagocytic CHO cells that express these receptors transiently. SIGNR1-expressing cells ingested liposomes coated with neoglycolipids with terminal mannose residues, such as Man2-, Man3-, and Man5-DPPE, and with a terminal N-acetylglucosamine. SIGNR1 mediated uptake of Man3-DPPE-coated liposomes most efficiently. Uptake of liposomes with lower neoglycolipid content by SIGNR3- or Langerin-expressing cells was slight or negligible, but uptake into these cells was detected for liposomes with higher neoglycolipid content. SIGNR1-expressing cells clearly ingested liposomes coated with Lewis X antigen, whereas SIGNR3- or Langerin-expressing cells barely ingested these liposomes, even at the higher neoglycolipid content. In contrast, SIGNR3 or Langerin, but not SIGNR1, mediated uptake of liposomes coated with blood group H antigen. These results indicate that CLRs with similar carbohydrate-recognition characteristics have distinct properties as pathogen-uptake receptors for carbohydrate-decorated particles.

Discrete palladium clusters that consist of two mutually bisecting perpendicular planes.

The construction of novel molecules with unprecedented alignments of the constituent elements has revolutionized the field of functional materials. The arrangement of two or more planar subunits in a mutually perpendicular fashion is a frequently encountered approach to produce novel functional materials. Previous examples of such materials can be categorized into two well-investigated families: spiro-conjugated and dumbbell-shaped structures, wherein the two planes are aligned orthogonally via a single atom or an axis, respectively. This article describes a third family: reaction of [Pd(CN t Bu)2]3 with Sn3Me8 or Ge6Me12 afforded a Pd7Sn4 cluster and a Pd8Ge6 cluster that consist of two mutually bisecting perpendicular planes. In the Pd7Sn4 cluster, the two equivalent Pd5Sn2 planes share three palladium atoms that include a dihedral angle of 85.6°.

Wall teichoic acid-dependent phagocytosis of intact cell walls of Lactiplantibacillus plantarum elicits IL-12 secretion from macrophages.

Selected lactic acid bacteria can stimulate macrophages and dendritic cells to secrete IL-12, which plays a key role in activating innate and cellular immunity. In this study, we investigated the roles of cell wall teichoic acids (WTAs) displayed on whole intact cell walls (ICWs) of Lactiplantibacillus plantarum in activation of mouse macrophages. ICWs were prepared from whole bacterial cells of several lactobacilli without physical disruption, and thus retaining the overall shapes of the bacteria. WTA-displaying ICWs of several L. plantarum strains, but not WTA-lacking ICWs of strains of other lactobacilli, elicited IL-12 secretion from mouse bone marrow-derived macrophages (BMMs) and mouse macrophage-like J774.1 cells. The ability of the ICWs of L. plantarum to induce IL-12 secretion was abolished by selective chemical elimination of WTAs from ICWs, but was preserved by selective removal of cell wall glycopolymers other than WTAs. BMMs prepared from TLR2- or TLR4-deficient mouse could secret IL-12 upon stimulation with ICWs of L. plantarum and a MyD88 dimerization inhibitor did not affect ICW-mediated IL-12 secretion. WTA-displaying ICWs, but not WTA-lacking ICWs, were ingested in the cells within 30 min. Treatment with inhibitors of actin polymerization abolished IL-12 secretion in response to ICW stimulation and diminished ingestion of ICWs. When overall shapes of ICWs of L. plantarum were physically disrupted, the disrupted ICWs (DCWs) failed to induce IL-12 secretion. However, DCWs and soluble WTAs inhibited ICW-mediated IL-12 secretion from macrophages. Taken together, these results show that WTA-displaying ICWs of L. plantarum can elicit IL-12 production from macrophages via actin-dependent phagocytosis but TLR2 signaling axis independent pathway. WTAs displayed on ICWs are key molecules in the elicitation of IL-12 secretion, and the sizes and shapes of the ICWs have an impact on actin remodeling and subsequent IL-12 production.

Development of peritoneal macrophage along a dendritic cell lineage in response to uptake of oligomannose-coated liposomes.

In this study, we investigate the potential of peritoneal macrophages to differentiate into dendritic cell (DCs) in response to preferential uptake of oligomannose-coated liposomes (OMLs). About 30% of peritoneal cells (PECs) preferentially took up OMLs that were administered into the peritoneal cavity. The OML-ingesting cells expressed CD11b and F4/80, but lacked CD11c expression, indicating that the OML-ingesting PECs with a CD11b(high)CD11c(-) phenotype are resident peritoneal macrophages. During in vitro cultivation, CD11c(+) cells arose among the PECs with ingested OMLs. CD11c(+) cells also developed among enriched peritoneal CD11b(high)CD11(-) cells from OML-treated mice, and the resulting CD11c(+) cells expressed co-stimulatory molecules and MHC class II. In addition, OML-ingesting CD11b(high)CD11c(+) cells were found in spleen after the enriched peritoneal macrophages with ingested OMLs were transplanted in the peritoneal cavity of mice. These results show that a fraction of peritoneal macrophages can differentiate into mature DCs following uptake of OMLs.

Importance of particle size of oligomannose-coated liposomes for induction of Th1 immunity.

Oligomannose-coated liposomes (OMLs) comprised of dipalmitoylphosphatidylcholine, cholesterol and Man3-DPPE at a molar ratio of 1:1:0.1 and particle diameters of about 1000 nm can induce liposome-encased antigen-specific strong Th1 immunity. In this study, we evaluated the effect of particle sizes of OMLs on induction of Th1 immune responses in mice. Spleen cells obtained from mice immunized with antigen-encapsulating OMLs with 1000- and 800-nm diameters secreted remarkably high levels of IFN-γ upon in vitro stimulation. In addition, sera of mice that received these OMLs had significantly higher titers of antigen-specific IgG2a than those of IgG1, which are commonly associated with Th1 responses. In contrast, treatment with antigen-encapsulating OMLs with 400- and 200-nm diameters failed to induce IFN-γ secretion from spleen cells, although these OMLs did elicit elevation of antigen-specific IgGs. In addition, the titers of serum antigen-specific IgG2a were the same as those of IgG1 in mice that received 400-nm OMLs. Resident peritoneal mononuclear phagocytes (MNPs) treated with OMLs of diameter ≥ 600 nm secreted IL-12, which is essential for induction of Th1 immune responses, while those treated with OMLs of ≤ 400 nm failed to produce this cytokine. However, 400-nm OMLs did induce enhanced expression of MHC class II and costimulatory molecules on MNPs, similarly to OMLs of ≥ 600 nm. Taken together, these results strongly indicate that OMLs of diameter ≥ 600 nm are required to induce Th1 immune responses against OML-encased antigens, although OMLs of diameter ≤ 400 nm can activate MNPs.

Approaching isotropic charge transport of n-type organic semiconductors with bulky substituents.

Benzo[de]isoquinolino[1,8-gh]quinolinetetracarboxylic diimide (BQQDI) is an n-type organic semiconductor that has shown unique multi-fold intermolecular hydrogen-bonding interactions, leading to aggregated structures with excellent charge transports and electron mobility properties. However, the strong intermolecular anchoring of BQQDI presents challenges for fine-tuning the molecular assembly and improving the semiconducting properties. Herein, we report the design and synthesis of two BQQDI derivatives with phenyl- and cyclohexyl substituents (Ph-BQQDI and Cy6-BQQDI), where the two organic semiconductors show distinct molecular assemblies and degrees of intermolecular orbital overlaps. In addition, the difference in their packing motifs leads to strikingly different band structures that give rise to contrasting charge-transport capabilities. More specifically, Cy6-BQQDI bearing bulky substituents exhibits isotropic intermolecular orbital overlaps resulting in equal averaged transfer integrals in both π-π stacking directions, even when dynamic disorders are taken into account; whereas Ph-BQQDI exhibits anisotropic averaged transfer integrals in these directions. As a result, Cy6-BQQDI shows excellent device performances in both single-crystalline and polycrystalline thin-film organic field-effect transistors up to 2.3 and 1.0 cm2 V-1 s-1, respectively.

SIGNR1 ligation on murine peritoneal macrophages induces IL-12 production through NFkappaB activation.

We have previously shown that murine resident peritoneal macrophages (PEMs) are activated in response to uptake of oligomannose-coated liposomes (OMLs), leading to production of interleukin (IL)-12. To understand the mechanism of activation of PEMs by OMLs, in the present study we investigated the role of a mannose-binding C-type lectin receptor, SIGNR1, in production of proinflammatory cytokines by PEMs, in which SIGNR1 acts as a physiological receptor for OMLs. Engagement of SIGNR1 on PEMs with an anti-SIGNR1-specific rat IgM antibody, ERTR9, induced production of IL-12 and tumor necrosis factor (TNF)-alpha from PEMs, while secretion of IL-6 and IL-1beta was not detected with the same treatment. The level of phosphorylated IkappaB kinase in PEMs also increased in response to ERTR9 treatment of the cells. Treatment of PEMs with a specific nuclear factor kappa-B (NFkappaB) inhibitor, BAY11-7082, reduced ERTR9-dependent IL-12 production. Intraperitoneal treatment with BAY11-7082 also led to reduction of subsequent OML-induced IL-12 production from PEMs. These results indicate that SIGNR1-mediated intercellular signaling may induce production of cytokines such as IL-12 through NFkappaB activation.

Mucosal adjuvant activity of oligomannose-coated liposomes for nasal immunization.

In the present study, we investigated the effectiveness of liposomes coated with a neoglycolipid consisting of mannotriose and dipalmitoylphosphatidylcholine (Man3-DPPE) as an adjuvant for induction of mucosal immunity. Immunization of BALB/c mice with ovalbumin (OVA)-encapsulated Man3-DPPE-coated liposomes (oligomannose-coated liposomes; OMLs) by a nasal route produced high levels of OVA-specific IgG and IgA antibodies in serum of immunized mice 1 week after the last nasal immunization, whereas no significant serum antibody responses were observed in mice that received OVA in uncoated liposomes or OVA alone. Seven weeks after the last nasal immunization, nasal challenge with an excess amount of OVA in mice that had received OVA/OMLs led to an anamnestic response to the antigen that resulted in 5- to 10-fold increases of antigen-specific serum IgG and IgA antibodies. Only mice immunized nasally with OML/OVA secreted antigen-specific secretory IgA in nasal washes and produced interferon-gamma secreting cells in nasopharyngeal-associated lymphoreticular tissue. Taken together, these results show that nasal administration of OMLs induces mucosal and systemic immunity that are specific for the entrapped antigen in the liposomes. Thus, liposomes coated with synthetic neoglycolipids might be useful as adjuvants for induction of mucosal immunity.

Neospora caninum: application of apical membrane antigen 1 encapsulated in the oligomannose-coated liposomes for reduction of offspring mortality from infection in BALB/c mice.

Liposomes coated with neoglycolipids constructed with mannopentaose and dipalmitoylphosphatidylethanolamine (M3-DPPE), referred to as M3-DPPE liposomes, have been shown to induce cellular immunity against antigens encapsulated therein. To evaluate whether these M3-DPPE liposomes have an adjuvant capacity against Neospora caninum infection, a novel immunization method utilizing soluble N. caninum apical membrane antigen 1 (NcAMA1) encapsulated in the M3-DPPE liposomes (M3-NcAMA1) was employed. The results revealed that a significant amount of interferon (IFN)-gamma production was detected in culture supernatants of NcAMA1 protein- or N. caninum lysate-stimulated spleen cells obtained from the mice one week after the third immunization with M3-NcAMA1. The parasite burden in the dams' brain tissue was decreased and the survival rate of offspring increased significantly in M3-NcAMA1-immunized mice. Thus, a parasite-specific Th1 immune response was successfully induced in the pregnant mice immunized with M3-NcAMA1, and an effective reduction of offspring mortality from N. caninum infection was triggered.

Cooperation of specific ICAM-3 grabbing nonintegrin-related 1 (SIGNR1) and complement receptor type 3 (CR3) in the uptake of oligomannose-coated liposomes by macrophages.

Resident peritoneal macrophages (PEMs) express SIGNR1 on the cell surface as a major mannose receptor. These cells also ingest oligomannose-coated liposomes (OMLs) in an oligomannose-dependent manner following intraperitoneal administration. Therefore, the current study was conducted to investigate the possible role of SIGNR1 in capture of OMLs. Transient expression of several SIGN-related lectins potentially expressed on PEMs in CHO cells revealed that only SIGNR1 contributed to capture of OMLs. When SIGNR1 was introduced into mouse macrophage-like RAW264.7 cells, SIGNR1-expressing RAW (RAW-SIGNR1) cells recognized OMLs under serum-free conditions. OML recognition by RAW-SIGNR1 cells as well as that by PEMs was partially inhibited by an anti-SIGNR1 antibody (ER-TR9) and by mannan, and completely inhibited by EDTA. Interestingly, OML recognition by RAW-SIGNR1 cells was accelerated in the presence of serum, partially inhibited by an anti-complement receptor 3 (CR3) antibody (M1/70), and almost completely inhibited by a combination of ER-TR9 and M1/70. Complete inhibition of OML ingestion by the combination of ER-TR9 and M1/70 was also observed under serum-free conditions, suggesting that SIGNR1 and CR3 cooperate in an additive way in capture of OMLs by macrophage-like RAW cells. Administration of ER-TR9 or M1/70 into the peritoneal cavity led to a significant decrease of OML uptake by PEMs. Therefore, SIGNR1 expressed on macrophages acts as a receptor for recognition of OMLs under physiological conditions.

Cross-linking of SIGNR1 activates JNK and induces TNF-alpha production in RAW264.7 cells that express SIGNR1.

In this study, we evaluated the signaling ability of SIGNR1 in murine macrophage-like RAW264.7 cells that stably expressed FLAG-tagged SIGNR1 (SIGNR1-FLAG). Cross-linking of SIGNR1-FLAG expressed on the cells by an anti-FLAG antibody induced JNK phosphorylation without induction of phosphorylation of ERK1/2 and p38 MAP kinase, and led to phosphorylations of Src family kinases (SFKs) and Akt. The SIGNR1-FLAG molecules in the cells were found in lipid raft-enriched membrane fractions, and the tyrosine kinases Lyn, Hck, and Fgr co-precipitated with SIGNR1-FLAG in the lipid raft fractions. The antibody-induced JNK phosphorylation was inhibited by inhibitors of SFKs and tyrosine kinases. Furthermore, cross-linking of SIGNR1 led to production of TNF-alpha, and the JNK inhibitor inhibited the antibody-induced TNF-alpha production. These results show that cross-linking of SIGNR1 triggers phosphorylation of SFKs, which leads to activation of the JNK pathway and induction of TNF-alpha production in macrophage-like RAW264.7 cells.

Regional expression of prosaposin in the wild-type and saposin D-deficient mouse brain detected by an anti-mouse prosaposin-specific antibody.

Prosaposin is a precursor of saposins A, B, C, and D. Saposins are indispensable for lysosomal hydrolysis of sphingolipids. The notion that prosaposin itself is likely involved in brain development led us to generate an anti-mouse prosaposin-specific antibody that do not cross-react with any of the processed saposins. We have used it to study expression of prosaposin in the brain of wild-type (WT) and saposin D knockout mice (Sap-D(-/-)). Immunoblot studies indicated that prosaposin, already abundant in the brain of WT, was dramatically increased in Sap-D(-/-). By immunohistochemistry, the brain of WT was rich in prosaposin in hippocampal CA3 pyramidal neurons, tufted cells and mitral cells in olfactory bulb, and cerebellar Purkinje cells. In Sap-D(-/-), immunoreactivity of prosaposin was increased in these neurons, most notably in the CA3 pyramidal neurons which contained prosaposin immuno-positive inclusion bodies in the endoplasmic reticulum. Further characterization of these prosaposin-rich neurons may provide new insights into the physiological functions of prosaposin in the nervous system.

Flows, stocks, and emissions of DEHP products in Japan.

The usage of products containing Bis (2­ethylhexyl) Phthalate (DEHP) is widespread, mainly through the great variety of PVC products. However, DEHP has become a worldwide concern, due to the potential health and environmental risks it presents. In this study, material flow analysis and emission estimations for DEHP products in Japan, from 1948 to 2030, were performed. Moreover, an evaluation of the potentially damaging impacts on human health and the environment was completed through a lifecycle impact assessment approach. The analysis focused on three representative lifecycle phases - Production, Use and Treatment and Disposal. The peak flows of DEHP from Production to the Use phase were in 1996 with 285,300 tons for shipment and the stocks peaked in 2001 with 1,981,908 tons. Accordingly, in 2006 the peak of DEHP waste to the Treatment and disposal phase was 190,792 tons. The primary emissions were observed in the Use phase, due to the large stocks, with DEHP mostly being released to the pedosphere. The total emissions from the Use phase reached the maximum of 48,960 tons in 2000, whereas in the Production and Treatment and disposal phase it was 248 tons and 15 tons, respectively. Subsequently, concerning the evaluation of impacts, the damage to the human health was the most widespread impact, totaling 13,782 disability-adjusted life years (DALYs), compared with the damage to the ecosystems, with 0.12 species·year. Furthermore, the risk-risk tradeoffs between the lifecycle phases were clarified throughout the years.

Oligomannose-coated liposomes activate ERK via Src kinases and PI3K/Akt in J774A.1 cells.

We have previously shown that liposomes coated with a neoglycolipid constructed from mannotriose and dipalmitoylphosphatidylethanolamine (Man3-DPPE) activate peritoneal macrophages to induce enhanced expression of co-stimulatory molecules and MHC class II. In this study, we investigated the signaling pathways activated by the Man3-DPPE-coated liposomes (OMLs) in a murine macrophage cell line, J774A.1. In response to OML stimulation, ERK among MAPKs was clearly and transiently phosphorylated in J774 cells. ERK phosphorylation was also induced by treatment of the cells with Man3-DPPE and Man3-BSA, but not by uncoated liposomes. In addition, rapid and transient phosphorylation of Akt and Src family kinases (SFKs) was observed in response to OMLs. OML-induced ERK phosphorylation was inhibited by specific inhibitors of PI3K and SFKs, and OML-induced Akt phosphorylation was inhibited by a inhibitor of SFKs. Therefore, OMLs may activate the PI3K/Akt pathway through phosphorylation of Src family kinases to induce ERK activation.

Effective induction of anti-tumor immune responses with oligomannose-coated liposome targeting to intraperitoneal phagocytic cells.

We recently established a novel drug delivery system (DDS) using oligomannose-coated liposomes (OMLs) which are probably taken up by macrophages (Mvarphi) to carry anti-cancer drugs to milky spots known as preferential metastatic sites of gastric cancers [Y. Ikehara, T. Niwa, L. Biao, S.K. Ikehara, N. Ohashi, T. Kobayashi, Y. Shimizu, N. Kojima, H. Nakanishi, A carbohydrate recognition-based drug delivery and controlled release system using intraperitoneal macrophages as a cellular vehicle, Cancer Res. 66 (2006) 8740-8748]. In the present study, we applied this intraperitoneal DDS for systemic cancer immunotherapy employing ovalbumin (OVA) as a model antigen. The cells taking up the OMLs containing FITC-OVA injected into the peritoneal cavity were predominantly Mvarphi, as they showed adhesive characteristics and expressed F4/80 and CD11b almost exclusively. The phagocytic cells also took up bare OVA directly to the same extent as OML-enclosed OVA (OML-OVA), as it is a highly mannosilated protein. The phagocytic cells taking up OML-OVA, however, could activate OVA-specific CD8+ (from OT-I: H-2Kb/OVA257-264-specific) and CD4+ (from OT-II: H-2Ab/OVA323-339-specific) T cells much more effectively in vitro than those taking up bare OVA. Furthermore, only the mice pre-immunized with OML-OVA rejected E.G7-OVA (OVA-transfected EL4) but not EL4. These results indicate that the OMLs can also be used as an effective antigen delivery system for cancer immunotherapy activating both CTL and Th subsets.