SHPS-1/SIRP1alpha contributes to interleukin-6 signalling

Cang-ai volatile oil alleviates nasal inflammation via Th1/Th2 cell imbalance regulation in a rat model of ovalbumin-induced allergic rhinitis

We previously revealed that Cang-ai volatile oil (CAVO) regulates T-cell activity, enhancing the immune response in people with chronic respiratory diseases. However, the effects of CAVO on allergic rhinitis (AR) have not been investigated. Herein, we established an ovalbumin (OVA)-induced AR rat model to determine these effects. Sprague-Dawley (SD) rats were exposed to OVA for 3 weeks. CAVO or loratadine (positive control) was given orally once daily for 2 weeks to OVA-exposed rats. Behavior modeling nasal allergies was observed. Nasal mucosa, serum, and spleen samples of AR rats were analyzed. CAVO treatment significantly reduced the number of nose rubs and sneezes, and ameliorated several hallmarks of nasal mucosa tissue remodeling: inflammation, eosinophilic infiltration, goblet cell metaplasia, and mast cell hyperplasia. CAVO administration markedly upregulated expressions of interferon-γ, interleukin (IL)-2, and IL-12, and downregulated expressions of serum tumor necrosis factor-α, IL-4, IL-5, IL-6, IL-13, immunoglobulin-E, and histamine. CAVO therapy also increased production of IFN-γ and T-helper type 1 (Th1)-specific T-box transcription factor (T-bet) of the cluster of differentiation-4+ T-cells in splenic lymphocytes, and protein and mRNA expressions of T-bet in nasal mucosa. In contrast, levels of the Th2 cytokine IL-4 and Th2-specific transcription factor GATA binding protein-3 were suppressed by CAVO. These cumulative findings demonstrate that CAVO therapy can alleviate AR by regulating the balance between Th1 and Th2 cells.

Molecular Pathways Governing the Termination of Liver Regeneration

The liver has the unique capacity to regenerate, and up to 70% of the liver can be removed without detrimental consequences to the organism. Liver regeneration is a complex process involving multiple signaling networks and organs. Liver regeneration proceeds through three phases: the initiation phase, the growth phase, and the termination phase. Termination of liver regeneration occurs when the liver reaches a liver-to-body weight that is required for homeostasis, the so-called "hepatostat." The initiation and growth phases have been the subject of many studies. The molecular pathways that govern the termination phase, however, remain to be fully elucidated. This review summarizes the pathways and molecules that signal the cessation of liver regrowth after partial hepatectomy and answers the question, "What factors drive the hepatostat?" SIGNIFICANCE STATEMENT: Unraveling the pathways underlying the cessation of liver regeneration enables the identification of druggable targets that will allow us to gain pharmacological control over liver regeneration. For these purposes, it would be useful to understand why the regenerative capacity of the liver is hampered under certain pathological circumstances so as to artificially modulate the regenerative processes (e.g., by blocking the cessation pathways) to improve clinical outcomes and safeguard the patient's life.

The immune-enhancing effects of a mixture of Astragalus membranaceus (Fisch.) Bunge, Angelica gigas Nakai, and Trichosanthes Kirilowii (Maxim.) or its active constituent nodakenin

ETHNOPHARMACOLOGICAL RELEVANCE

A mixture (SH003) of Astragalus membranaceus (Fisch.) Bunge, Angelica gigas Nakai, and Trichosanthes Kirilowii (Maxim.) has beneficial effects against several carcinomas. There have been few reports on an immune-enhancing activity of SH003 and its active constituent nodakenin.

AIM OF THE STUDY

This study aimed at identifying the immune-enhancing effect of SH003 and nodakenin.

MATERIALS AND METHODS

The immune-enhancing effect was evaluated using RAW264.7 macrophages, mouse primary splenocytes, and a cyclophosphamide (CP)-induced immunosuppression murine model.

RESULTS

The results show that SH003 or nodakenin stimulated the production levels of granulocyte colony-stimulating factor, IL-12, IL-2, IL-6, TNF-α, and nitric oxide (NO) and the expression levels of iNOS in RAW264.7 macrophages. SH003 or nodakenin also enhanced NF-κB p65 activation in RAW264.7 macrophages. SH003 or nodakenin stimulated the production levels of IFN-γ, IL-12, IL-2, TNF-α, and NO and the expression levels of iNOS in splenocytes. SH003 or nodakenin increased the splenic lymphocyte proliferation and splenic NK cell activity. In addition, SH003 or nodakenin increased the levels of IFN-γ, IL-12, IL-2, IL-6, and TNF-α in the serum and spleen of CP-treated mice, alleviating CP-induced immunosuppression.

CONCLUSION

Taken together, the results of this study show that SH003 improved immunosuppression through the activation of macrophages, splenocytes, and NK cells. These findings suggest that SH003 could be applied as a potential immunostimulatory agent for a variety of diseases caused or exacerbated by immunodeficiency.

In Vivo and In Vitro Study of Immunostimulation by Leuconostoc lactis-Produced Gluco-Oligosaccharides

Glycosyltransferase-producing Leuconostoc lactis CCK940 produces CCK- oligosaccharides, gluco-oligosaccharide molecules, using sucrose and maltose as donor and acceptor molecules, respectively. In this study, the immunostimulatory activities of CCK-oligosaccharides on RAW264.7 macrophages and BALB/c mice were evaluated. CCK-oligosaccharides induced the expression of phosphorylated-p38, extracellular-signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) and upregulation of phagocytic activity in RAW264.7 macrophages, suggesting their involvement in mitogen-activated protein kinase (MAPK) signaling pathway and phagocytosis. When CCK-oligosaccharides were administered to mice intraperitoneally injected with cyclophosphamide (CY), spleen indices and expressions of interleukin (IL)-6, IL–10, and tumor necrosis factor-α increased, compared with those in only CY-treated group. These findings suggest that CCK-oligosaccharides can be used as an effective immunostimulating agent.

Effect of sulfated yeast beta-glucan on cyclophosphamide-induced immunosuppression in chickens

Immunosuppression is a condition that causes large economic losses in the poultry industry. To investigate the effect of sulfated yeast beta-glucan on immunosuppression, two hundred and fifty 11-day-old chickens were randomly assigned to five groups, and except for the normal control group, injected with cyclophosphamide once a day for 3 successive days. At 14 days of age, sulfated yeast beta-glucan from Saccharomyces cerevisiae(sGSC) was orally administered at three doses to the chickens in three experimental groups for 14 days. On days 7 and 14 after the first sGSC dose, serum cytokine concentrations and peripheral lymphocyte proliferation were measured. Gut microbiota, organ index, and histopathological changes in the bursa were investigated on day 14. The results demonstrated that at 4 mg/kg, sGSC could significantly enhance the bursa index and IFN-γ and IL-6 concentrations, decrease TGF-β1 concentration, and promote lymphocyte proliferation; it could effectively decrease histopathological changes in the bursa and improve gut Bifidobacterium and Lactobacillus populations in cecal digesta of chickens compared with the model control group. This indicated that sGSC could effectively alleviate immunosuppression and regulate the beneficial microbiota in the gut.

TRIM2, a novel member of the antiviral family, limits New World arenavirus entry

Tripartite motif (TRIM) proteins belong to a large family with many roles in host biology, including restricting virus infection. Here, we found that TRIM2, which has been implicated in cases of Charcot-Marie-Tooth disease (CMTD) in humans, acts by blocking hemorrhagic fever New World arenavirus (NWA) entry into cells. We show that Trim2-knockout mice, as well as primary fibroblasts from a CMTD patient with mutations in TRIM2, are more highly infected by the NWAs Junín and Tacaribe virus than wild-type mice or cells are. Using mice with different Trim2 gene deletions and TRIM2 mutant constructs, we demonstrate that its antiviral activity is uniquely independent of the RING domain encoding ubiquitin ligase activity. Finally, we show that one member of the TRIM2 interactome, signal regulatory protein α (SIRPA), a known inhibitor of phagocytosis, also restricts NWA infection and conversely that TRIM2 limits phagocytosis of apoptotic cells. In addition to demonstrating a novel antiviral mechanism for TRIM proteins, these studies suggest that the NWA entry and phagocytosis pathways overlap.

Purification, antitumor and anti-inflammation activities of an alkali-soluble and carboxymethyl polysaccharide CMP33 from Poria cocos

A carboxymethyl polysaccharide CMP33 (15.23 × 10⁴ Da) was isolated from edible and pharmaceutical mushroom Poria cocos using alkaline extraction followed by DEAE-52 and Saphadex-G200 + Saphadex-G150 column chromatographies. The structure analysis showed that CMP33 was composed of glucosyl residues containing a backbone chain of (1 → 3)-linked glucose residues and side chains of (1 → 6) and (1 → 2)-linked glucose residues, and possessed triple-helix structure. Bioassay results revealed that CMP33 displayed a dose-dependent inhibition on 5 cancer cells (HepG-2, MCF-7, SGC-7901, A549) in the range of 31.25-1000 μg/mL, but low cytotoxicity on normal liver cells L-O2. Moreover, CMP33 stimulated NO release and cytokine secretion (IL-1β, IL-6 and TNF-α), and also inhibited LPS-stimulated overproduction of NO, IL-6, TNF-α and IL-1β, in RAW264.7 cells. These results suggested that CMP33 possessed anticancer, anti-inflammation and immune-stimulation activities, and potential for developing as a bioactive ingredient in functional foods.

Physicochemical properties, immunostimulatory activity of the Lachnum polysaccharide and polysaccharide-dipeptide conjugates

The physicochemical properties and the immunoregulatory actions in vitro of an exopolysaccharide from Lachnum (LEP) and its conjugation with a dipeptide (LEP-RH) were investigated aiming to improve their functional characteristics. The structure characteristic of the LEP and LEP-RH were determined via FT-IR and NMR. The physicochemical properties were evaluated by scanning electron microscopy (SEM), rheometer, and differential scanning calorimeter (DSC). SEM results showed that LEP-RH had a rough surface and relatively loose distribution that different from LEP. Rheological studies of LEP and LEP-RH at the same concentration indicated that LEP and LEP-RH have similar shear-thinning behaviors and gel-like structures, while LEP-RH has a better thermal stability than LEP. Bioassay results showed that treatment with the higher dosage (200 μg/mL) of LEP and LEP-RH stimulated the proliferation, cytokine secretion (IL-2, IL-6 and TNF-α) of RAW264.7 macrophages.

Sargassum Fusiforme Polysaccharide SFP-F2 Activates the NF-κB Signaling Pathway via CD14/IKK and P38 Axes in RAW264.7 Cells

Sargassum fusifrome is considered a "longevity vegetable" in Asia. Sargassum fusifrome polysaccharides exhibit numerous biological activities, specially, the modulation of immune response via the NF-κB signaling pathway. However, the precise mechanisms by which these polysaccharides modulate the immune response through the NF-κB signaling pathway have not been elucidated. In this study, we purified and characterized a novel fraction of Sargassum fusifrome polysaccharide and named it SFP-F2. SFP-F2 significantly upregulated the production of the cytokines TNF-α, IL-1β and IL-6 in RAW264.7 cells. It also activated the NF-κB signaling pathway. Data obtained from experiments carried out with specific inhibitors (PDTC, BAY 11-7082, IKK16 and SB203580) suggested that SFP-F2 activated the NF-κB signaling pathway via CD14/IKK and P38 axes. SFP-F2 could therefore potentially exert an immune-enhancement effect through inducing the CD14/IKK/NF-κB and P38/NF-κB signaling pathways.

Immunomodulatory activity of Lactobacillus plantarum KLDS1.0318 in cyclophosphamide-treated mice

Background

Probiotics in fermented foods have attracted considerable attention lately as treatment options for immune diseases, the incidence of which has been increasing throughout the world.

Objective

The objective of the present study was to investigate the immunomodulatory activity of Lactobacillus plantarum (L. plantarum) KLDS1.0318 in cyclophosphamide-treated mice.

Design

To investigate the immune-enhancing effects of L. plantarum KLDS1.0318, we used a immunosuppressive model. Ninety female six-week-old BALB/c mice were randomly divided into six groups: normal control (NC) group, model control (MC) group, immunosuppression plus L. plantarum KLDS1.0318 groups with three different doses (KLDS1.0318-L, KLDS1.0318-M, and KLDS1.0318-H), and plus levamisole hydrochloride as positive control (PC) group.

Results and discussions

Results showed that the thymus and spleen indexes of the four treatment groups were significantly higher than those of the MC group (2.01±0.16) ( p < 0.05). The capacity of lymphocyte proliferation, the activity of natural killer (NK) cell and macrophages phagocytosis were significantly increased ( p < 0.05) in four treatment groups as compared with the MC group (0.327±0.022, 62.29±0.8, 0.087±0.008, respectively). The levels of relative immune factors (IL-2, IL-6, and IFN-γ) showed similar patterns ( p < 0.05).

Conclusions

This study suggested that orally administered L.plantarum KLDS1.0318 may effectively accelerate the recovery of immunosuppressive mice caused by cyclophosphamide (CTX). The immunomodulatory activity of the srtain recommended that L. plantarum KLDS1.0318 could be used as a powerful medicinal treatment against immunosuppression.

Structural Characterization and Immunostimulatory Activity of Polysaccharides from Brassica rapa L.

Two neutral polysaccharides (BRNP-1, 6.9 kDa; BRNP-2, 4.8 kDa) were purified from the common edible plant Brassica rapa L. via the combined techniques of ion-exchange chromatography and high-performance gel permeation chromatography. Monosaccharide composition analysis showed that BRNP-1 and BRNP-2 were composed of glucosyl residues. Methylation and 1D- and 2D-NMR analyses revealed that both BRNP-1 and BRNP-2 contained a backbone chain that was composed of α-D-(1 → 4)-linked Glcp residues and side chains that were composed of terminally linked Glcp residues attached at the O-6 position of backbone-glycosyl residues. BRNP-1 and BRNP-2, however, differed in branch degree and molecular weight. Bioassay results showed that treatment with the higher dosage (400 μg/mL) of BRNP-1 and BRNP-2 stimulated the proliferation, NO release, and cytokine secretion (IL-6 and TNF-α) of RAW264.7 macrophages. These results suggested that BRNP-1 and BRNP-2 may enhance macrophage-mediated immune responses.

Cheonggukjang polysaccharides enhance immune activities and prevent cyclophosphamide-induced immunosuppression

Cheonggukjang is a traditional Korean fermentation product prepared from soybean that is reported to have various biological functions. We previously reported that the polysaccharides from Cheonggukjang (PSCJ) have immunostimulatory activities in RAW 264.7 macrophages and primary cultured splenocytes. In this study, the immunostimulatory activities of the PSCJ were investigated further using various experimental models such as in vitro, ex vivo, and in vivo. The PSCJ was able to stimulate the complement system (ITCH50: 30.6%). In primary cultured mouse peritoneal macrophages, the PSCJ was found to significantly increase nitric oxide and immunostimulatory cytokines (IL-6 and IL-12) production in a concentration-dependent manner (1-100 μg/mL). In the normal mice model, the oral administration of the PSCJ increased the weight of spleen (p < 0.05 at 100 and 200 mg/kg) and improved the phagocytic rates of peritoneal macrophages (p < 0.05 at 200 mg/kg) and lymphocytes proliferation (p < 0.05 at 100 and 200 mg/kg). Similarly, the PSCJ markedly restored the decreased lymphocytes proliferation (p < 0.01 at 200 mg/kg), natural killer cell activity (p < 0.01 at 200mg/kg), and white blood cell count (p<0.01 at 100 and 200 mg/kg) in the cyclophosphamide-induced immunosuppressed mice model. These results suggest that the PSCJ could be utilized as an effective immunostimulatory agent.

Sargassum fusiforme polysaccharide activates nuclear factor kappa-B (NF-κB) and induces cytokine production via Toll-like receptors

This study was designed to investigate the mechanism of macrophage activation by the Sargassum fusiforme polysaccharide (SFPS). As a result, SFPS significantly enhanced cytokines and nitric oxide (NO) productions in peritoneal macrophages, and stimulated macrophages to produce the cytokines and NO through the induction of their genes expression. The pretreatment of peritoneal macrophages with special antibodies [Toll-like receptors (TLRs) antibody] significantly blocked SFPS-induced tumor necrosis factor alpha (TNF-α) and NO production. Furthermore, pyrrolidine dithiocarbamate (PDTC), a specific inhibitor of NF-κB, effectively suppressed SFPS-induced TNF-α and interleukin 1β (IL-1β) secretion in peritoneal macrophages, indicating that SFPS stimulated macrophages to produce cytokines through the NF-κB pathway and the result was further confirmed by the experiment of Western blotting (WB) and confocal laser scanning microscope (CLSM). Taken together, these results suggest that SFPS-mediated induction of cytokines and NO production in macrophages is mediated, at least in part, by TLRs/NF-κB signaling pathway.

Protein tyrosine phosphatases as wardens of STAT signaling

Signaling by signal transducers and activators of transcription (STATs) is controlled at many levels of the signaling cascade. Protein tyrosine phosphatases (PTPs) regulate STAT activation at several layers, including direct pSTAT dephosphorylation in both cytoplasm and nucleus. Despite the importance of this regulation mode, many aspects are still incompletely understood, e.g., the identity of PTPs acting on certain members of the STAT family. After a brief introduction into the STAT and PTP families, we discuss here the current knowledge on PTP mediated regulation of STAT activity, focusing on the interaction of individual STATs with specific PTPs. Finally, we highlight open questions and propose important tasks of future research.

SHPS-1 and a synthetic peptide representing its ITIM inhibit the MyD88, but not TRIF, pathway of TLR signaling through activation of SHP and PI3K in THP-1 cells

BACKGROUND

Src homology 2 domain-containing protein tyrosine phosphatase substrate (SHPS)-1 is known to have regulatory effects on myeloid cells. However, its role in macrophage activation is not clearly understood.

METHODS AND RESULTS

In order to investigate the role of SHPS-1 in Toll-like receptor (TLR)-mediated activation, human monocytic cell lines were treated with anti-SHPS-1 monoclonal antibody. The triggering of SHPS-1 blocked the expression of IL-8 and TNF-α in cells treated with a TLR4 ligand that induces a signaling pathway involving myeloid differentiation factor 88 (MyD88) and Toll-interleukin-1 receptor (TIR)-domain-containing adapter-inducing interferon-β (TRIF). Interestingly, SHPS-1 inhibited TLR9/MyD88-mediated, but not TLR3/TRIF-mediated, expression of IL-8. Accordingly, a synthetic peptide representing the immunoreceptor tyrosine-based inhibition motif (ITIM) of SHPS-1 suppressed only the MyD88 pathway. Utilization of specific inhibitors and Western blot analysis indicated that the inhibitory effects were mediated by Src homology 2 domain-containing phosphatases (SHPs) and phosphoinositide 3-kinase (PI3K).

CONCLUSION

SHPS-1 negatively regulates the MyD88-dependent TLR signaling pathway through the inhibition of NF-κB activation.

A polysaccharide from Sargassum fusiforme protects against immunosuppression in cyclophosphamide-treated mice

A water-soluble polysaccharide (SFPS) isolated from Sargassum fusiforme was purified by DEAE-52 cellulose anion-exchange and Sephadex G-200 gel filtration chromatography. The high performance gel permeation chromatography (HPGPC) analysis showed that the average molecular weight (Mw) of SFPS was 299 kDa. The SFPS was composed of D-fucose, L-xylose, D-mannose and D-galactose in a molar ratio of 5.9:1.0:2.3:2.2. The results showed that SFPS stimulated proliferation and the cytokines (IL-2, IL-6 and IFN-γ) secretion of splenic lymphocytes in cyclophosphamide-induced immunosuppressed mice. SFPS markedly increased the phagocytic rates and cytokines (IL-2, IL-6 and TNF-α) secretion of peritoneal macrophages. Administration of SFPS significantly raised spleen index. It could act as an efficacious adjacent immunopotentiating therapy or an alternative means in lessening chemotherapy-induced immunosuppression, and also can be utilized as immunostimulants for food and pharmaceutical industries.

SHPS-1 deficiency induces robust neuroprotection against experimental stroke by attenuating oxidative stress

Src homology 2 domain-containing protein tyrosine phosphatase substrate-1 (SHPS-1), also known as Signal-regulatory protein alpha (SIRPα) or SIRPA is a transmembrane protein that is predominantly expressed in neurons, dendritic cells, and macrophages. This study was conducted to investigate the role of SHPS-1 in the oxidative stress and brain damage induced by acute focal cerebral ischemia. Wild-type (WT) and SHPS-1 mutant (MT) mice were subjected to middle cerebral artery occlusion (60 min) followed by reperfusion. SHPS-1 MT mice had significantly reduced infarct volumes and improved neurological function after brain ischemia. In addition, neural injury and oxidative stress were inhibited in SHPS-1 MT mice. The mRNA and protein levels of the antioxidant genes nuclear factor-E2-related factor 2 (Nrf2) and heme oxygenase 1 were up-regulated in SHPS-1 MT mice. The SHPS-1 mutation suppressed the phosphorylation of SHP-1 and SHP-2 and increased the phosphorylation of Akt and GSK3β. These results provide the first demonstration that SHPS-1 plays an important role in the oxidative stress and brain injury induced by acute cerebral ischemia. The activation of Akt signaling and the up-regulation of Nrf2 and heme oxygenase 1 likely account for the protective effects that were observed in the SHPS-1 MT mice.

Signal regulatory protein alpha (SIRPalpha)/CD47 interaction and function

SIRPalpha is an inhibitory receptor present on myeloid cells that interacts with a widely distributed membrane protein CD47. The activating member SIRPbeta, despite extensive sequence similarity to SIRPalpha in the extracellular region, shows negligible binding to CD47. The SIRPalpha/CD47 interaction is unusual in that it can lead to bidirectional signalling through both SIRPalpha and CD47. This review concentrates on the interactions of SIRPalpha with CD47 where recent data have shed light on the structure of the proteins including determining why the activating SIRPbeta does not bind CD47, evidence of extensive polymorphisms and implication for the evolution and function of this protein and paired receptors in general. The interaction may be modified by endocytosis of the receptors, cleavage by proteolysis and through interactions of surfactant proteins.