Hernandezine acts as a CDK4 suppressor inhibiting tumor growth by the CDK4/PKM2/NRF2 axis in colon cancer.

BACKGROUND: The cyclin-dependent kinase 4 (CDK4) interacts with its canonical and non-canonical substrates modulating the cell cycle in tumor cells. However, the potential substrates and the beyond-cell-cycle-regulated functions of CDK4 in colon cancer (CC) are still unknown. Hernandezine (HER) is previously verified to induce G0/G1 phase arrest and autophagic cell death in human cancer cells, which implies that HER might target G0/G1 phase-related proteins, including CDK4. PURPOSE: The present study tried to investigate the glycolytic metabolism and oxidative stress functions of CDK4 in colon cancer. Furthermore, the inhibitory effects and potential binding sites of HER on CDK4, as well as its anti-tumor activity were investigated in CC cells. METHODS: The mass spectrometry assay was performed to identify potential endogenous substrates of CDK4 and the correlation between glycolytic metabolic rate and CDK4 level in COAD patient tissues. Meanwhile, after inhibiting the activity or the expression of CDK4, the binding capacity of CDK4 to PKM2 and NRF2 and the latter two protein distributions in cytoplasm and nucleus were detected in CC cells. In vitro, the regulatory effects of the CDK4-PKM2-NRF2 axis on glycolysis and oxidative stress were performed by ECAR, OCR, and ROS assay. The inhibitory effect of HER on CDK4 activity was explored in CC cells and the potential binding sites were predicted and testified in vitro. Furthermore, tumor growth inhibition of HER by suppressing the CDK4-PKM2-NRF2 axis was also investigated in vitro and in vivo. RESULTS: PKM2 and NRF2 were identified as endogenous substrates of CDK4 and, high-expressed CDK4 was associated with low-level glycolysis in COAD. In vitro, inactivated CDK4 facilitated CDK4-PKM2-NRF2 complex formation which resulted in 1) inhibited PKM2 activity and retarded the glycolytic rate; 2) cytoplasm-detained NRF2 failed to transcript anti-oxidative gene expressions and induced oxidant stress. Additionally, as a CDK4 inhibitor, HER developed triple anti-tumor effects including induced G0/G1 phase arrest, suppressed glycolysis, and disrupted the anti-oxidative capacity of CC cells. CONCLUSION: The results first time revealed that CDK4 modulated glycolytic and anti-oxidative capacity of CC cells via bound to its endogenous substrates, PKM2 and NRF2. Additionally, 140Asp145Asn amino acid sites of CDK4 were potential targets of HER. HER exerts anti-tumor activity by inhibited the activity of CDK4, promoted the CDK4-PKM2-NRF2 complex formation in the CC cells.

Single-cell transcriptomic analysis of decidual immune cell landscape in the occurrence of adverse pregnancy outcomes induced by Toxoplasma gondii infection.

BACKGROUND: Toxoplasma gondii is an obligate intracellular parasite that can lead to adverse pregnancy outcomes, particularly in early pregnancy. Previous studies have illustrated the landscape of decidual immune cells. However, the landscape of decidual immune cells in the maternal-fetal microenvironment during T. gondii infection remains unknown. METHODS: In this study, we employed single-cell RNA sequencing to analyze the changes in human decidual immune cells following T. gondii infection. The results of scRNA-seq were further validated with flow cytometry, reverse transcription-polymerase chain reaction, western blot, and immunofluorescence staining. RESULTS: Our results showed that the proportion of 17 decidual immune cell clusters and the expression levels of 21 genes were changed after T. gondii infection. Differential gene analysis demonstrated that T. gondii infection induced the differential expression of 279, 312, and 380 genes in decidual NK cells (dNK), decidual macrophages (dMφ), and decidual T cells (dT), respectively. Our results revealed for the first time that several previously unknown molecules in decidual immune cells changed following infection. This result revealed that the function of maternal-fetal immune tolerance declined, whereas the killing ability of decidual immune cells enhanced, eventually contributing to the occurrence of adverse pregnancy outcomes. CONCLUSIONS: This study provides valuable resource for uncovering several novel molecules that play an important role in the occurrence of abnormal pregnancy outcomes induced by T. gondii infection.

Telocinobufagin, a PLK1 suppressor that inhibits tumor growth and metastasis by modulating CDC25c and CTCF in HNSCC cells.

BACKGROUND: The high metastasis and mortality rates of head and neck squamous cell carcinoma (HNSCC) urgently require new treatment targets and drugs. A steroidal component of ChanSu, telocinobufagin (TBG), was verified to have anti-cancer effects in various tumors, but its activity and mechanism in anti-HNSCC were still unknown. PURPOSE: This study tried to demonstrate the anti-tumor effect of TBG on HNSCC and verify its potential mechanism. METHODS: The effect of TBG on cell proliferation and metastasis were performed and the TBG changed genes were detected by RNA-seq analysis in HNSCC cells. The GSEA and PPI analysis were used to identify the pathways targeted for TBG-regulated genes. Meanwhile, the mechanism of TBG on anti-proliferative and anti-metastasis were investigated in vitro and in vivo. RESULTS: The in vitro and in vivo experiments confirmed that TBG has favorable anti-tumor effects by induced G2/M phase arrest and suppressed metastasis in HNSCC cells. Further RNA-seq analysis demonstrated the genes regulated by TBG were enriched at the G2/M checkpoint and PLK1 signaling pathway. Then, the bioinformatic analysis of clinical data found that high expressed PLK1 were closely associated with poor overall survival in HNSCC patients. Furthermore, PLK1 directly and indirectly modulated G2/M phase and metastasis (by regulated CTCF) in HNSCC cells, simultaneously. TBG significantly inhibited the protein levels of PLK1 in both phosphorylated and non-phosphorylated forms and then, in one way, inactivated PLK1 failed to activate G2/M phase-related proteins (including CDK1, CDC25c, and cyclin B1). In another way, be inhibited PLK1 unable promote the nuclear translocation of CTCF and thus suppressed HNSC cell metastasis. In contrast, the anti-proliferative and anti-metastasis effects of TBG on HNSCC cell were vanished when cells high-expressed PLK1. CONCLUSION: The present study verified that PLK1 mediated TBG induced anti-tumor effect by modulated G2/M phase and metastasis in HNSCC cells.

Procyanidin C1 inhibits tumor growth and metastasis in colon cancer via modulating miR-501-3p/HIGD1A axis.

INTRODUCTION: Although colon (COAD) and rectal adenocarcinoma (READ) combined to refer to colorectal cancer (CRC), substantial clinical evidence urged that CRC should be treated as two different cancers due to compared with READ, COAD showed higher morbidity and worse 5-year survival. OBJECTIVES: This study has tried to screen for the crucial gene that caused the worse prognosis and investigate its mechanism for mediating tumor growth and metastases in COAD. Meanwhile, the potential anti-COAD compound implicated in this mechanism was identified and testified from 1,855 food-borne chemical kits. This study aims to bring a new perspective to the development of new anti-COAD drugs and personalized medicine for patients with COAD. METHODS AND RESULTS: The survival-related hub genes in COAD and READ were screened out from The Cancer Genome Atlas (TCGA) database and the results showed that HIGD1A, lower expressed in COAD than in READ, was associated with poor prognosis in COAD patients, but not in READ. Over-expressed HIGD1A suppressed CRC cell proliferation, invasion, and migration in vitro and in vivo. Meanwhile, the different expressed microRNA profiles between COAD and READ showed that miR-501-3p was highly expressed in COAD and inhibited HIGD1A expression by targeting 3'UTR of HIGD1A. MiR-501-3p mimics promoted cell proliferation and metastasis in CRC cells. In addition, Procyanidin C1 (PCC1), a kind of natural polyphenol has been verified as a potential miR-501-3p inhibitor. In vitro and in vivo, PCC1 promoted HIGD1A expression by suppressing miR-501-3p and resulted in inhibited tumor growth and metastasis. CONCLUSION: The present study verified that miR-501-3p/HIGD1A axis mediated tumor growth and metastasis in COAD. PCC1, a flavonoid that riched in food exerts anti-COAD effects by inhibiting miR-501-3p and results in the latter losing the ability to suppress HIGD1A expression. Subsequently, unfettered HIGD1A inhibited tumor growth and metastasis in COAD.

Shen-Qi-Jiang-Tang granule ameliorates diabetic nephropathy via modulating tumor necrosis factor signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Shen-Qi-Jiang-Tang granule (SQJTG), a classic traditional Chinese medicine (TCM) prescription, has been widely used in clinical for diabetes, especially type Ⅱ diabetes. Previous anti-diabetic studies stumbled across that SQJTG has a potential kidney protective effect on diabetic nephropathy (DN). However, the protective mechanism of SQJTG on DN still needs to be explored. AIM OF THE STUDY: The purpose of the present study was to explore the therapeutic effect of SQJTG on DN through both bioinformatics analysis and in vivo experiments. METHODS AND MATERIALS: The TCMIP database was used for screening potential compounds and targets of SQJTG, and the GeneCards, OMIM, DrugBank, and TTD databases were used for collecting DN-related genes. Then protein-protein interaction analysis for the common targets of SQJTG and DN was performed by the STRING database. Meanwhile, KEGG and GO were carried out using the Metascape and DAVID databases. In vivo experiments, to testify the potential kidney protective effects of SQJTG, STZ-induced DN mice with different dosages of SQJTG treatment were collected and the renal tissues were detected by H&E, PAS, Masson and TUNEL staining. Immunohistochemistry and immunoblotting were used to assess the proteins' expressions. Flow cytometry and ELISA assay were used to detect the levels of pro-inflammatory cytokines. RESULTS: Among the 338 compounds ascertained by SQJTG, there were 789 related targets as well. Moreover, 1,221 DN-related targets were predicted and 20 core targets were screened by the PPI analyses. According to GO and KEGG pathway analysis, SQJTG may affect DN via the TNF pathway. For the in vivo experiments, renal histomorphological examinations demonstrated that SQJTG treatment significantly ameliorated STZ-induced kidney damage and had a dosage dependence. Meanwhile, mice with DN were found to have dramatic increases in IL-1, TNF-α, IL-6, and IL-12, but markedly decreased after administration of SQJTG. In addition, the protein levels of TNF signaling molecules, like p-P65, p-JNK, and p-p38, showed significantly elevated in kidney tissues of DN mice and attenuated after SQJTG treatment. CONCLUSIONS: SQJTG exerts a kidney protective effect in DN mice via modulating TNF signaling pathways, and it has promising applications for the treatment of DN.

Effect of B7-H4 downregulation induced by Toxoplasma gondii infection on dysfunction of decidual macrophages contributes to adverse pregnancy outcomes.

BACKGROUND: Toxoplasma gondii infection during pregnancy can lead to fetal defect(s) or congenital complications. The inhibitory molecule B7-H4 expressed on decidual macrophages (dMφ) plays an important role in maternal-fetal tolerance. However, the effect of B7-H4 on the function of dMφ during T. gondii infection remains unclear. METHODS: Changes in B7-H4 expression on dMφ after T. gondii infection were explored both in vivo and in vitro. B7-H4-/- pregnant mice (pregnant mice with B7-H4 gene knockout) and purified primary human dMφ treated with B7-H4 neutralizing antibody were used to explore the role of B7-H4 signaling on regulating the membrane molecules, synthesis of arginine metabolic enzymes and cytokine production by dMφ with T. gondii infection. Also, adoptive transfer of dMφ from wild-type (WT) pregnant mice or B7-H4-/- pregnant mice to infected B7-H4-/- pregnant mice was used to examine the effect of B7-H4 on adverse pregnancy outcomes induced by T. gondii infection. RESULTS: The results illustrated that B7-H4-/- pregnant mice infected by T. gondii had poorer pregnancy outcomes than their wild-type counterparts. The expression of B7-H4 on dMφ significantly decreased after T. gondii infection, which resulted in the polarization of dMφ from the M2 toward the M1 phenotype by changing the expression of membrane molecules (CD80, CD86, CD163, CD206), synthesis of arginine metabolic enzymes (Arg-1, iNOS) and production of cytokines (IL-10, TNF-α) production. Also, we found that the B7-H4 downregulation after T. gondii infection increased iNOS and TNF-α expression mediated through the JAK2/STAT1 signaling pathway. In addition, adoptive transfer of dMφ from a WT pregnant mouse donor rather than from a B7-H4-/- pregnant mouse donor was able to improve adverse pregnancy outcomes induced by T. gondii infection. CONCLUSIONS: The results demonstrated that the downregulation of B7-H4 induced by T. gondii infection led to the dysfunction of decidual macrophages and contributed to abnormal pregnancy outcomes. Moreover, adoptive transfer of B7-H4+ dMφ could improve adverse pregnancy outcomes induced by T. gondii infection.

Tim-3 downregulation by Toxoplasma gondii infection contributes to decidual dendritic cell dysfunction.

BACKGROUND: Women in early pregnancy infected by Toxoplasma gondii may have severe adverse pregnancy outcomes, such as spontaneous abortion and fetal malformation. The inhibitory molecule T cell immunoglobulin and mucin domain 3 (Tim-3) is highly expressed on decidual dendritic cells (dDCs) and plays an important role in maintaining immune tolerance. However, whether T. gondii infection can cause dDC dysfunction by influencing the expression of Tim-3 and further participate in adverse pregnancy outcomes is still unclear. METHODS: An abnormal pregnancy model in Tim-3-deficient mice and primary human dDCs treated with Tim-3 neutralizing antibodies were used to examine the effect of Tim-3 expression on dDC dysfunction after T. gondii infection. RESULTS: Following T. gondii infection, the expression of Tim-3 on dDCs was downregulated, those of the pro-inflammatory functional molecules CD80, CD86, MHC-II, tumor necrosis factor-α (TNF-α), and interleukin-12 (IL-12) were increased, while those of the tolerant molecules indoleamine 2,3-dioxygenase (IDO) and interleukin-10 (IL-10) were significantly reduced. Tim-3 downregulation by T. gondii infection was closely associated with an increase in proinflammatory molecules and a decrease in tolerant molecules, which further resulted in dDC dysfunction. Moreover, the changes in Tim-3 induced by T. gondii infection further reduced the secretion of the cytokine IL-10 via the SRC-signal transducer and activator of transcription 3 (STAT3) pathway, which ultimately contributed to abnormal pregnancy outcomes. CONCLUSIONS: Toxoplasma gondii infection can significantly downregulate the expression of Tim-3 and cause the aberrant expression of functional molecules in dDCs. This leads to dDC dysfunction, which can ultimately contribute to abnormal pregnancy outcomes. Further, the expression of the anti-inflammatory molecule IL-10 was significantly decreased by Tim-3 downregulation, which was mediated by the SRC-STAT3 signaling pathway in dDCs after T. gondii infection.

A novel 2B4 receptor leads to worse pregnancy outcomes by facilitating TNF-α and IFN-γ production in dNK cells during Toxoplasma gondii infection.

BACKGROUND: Infections are a major threat to human reproductive health because they can induce pregnancy failure, including recurrent abortion, stillbirth, and preterm birth. Toxoplasma gondii (T. gondii) infection can result in adverse pregnancy outcomes by affecting certain immune molecules and cytokines. However, the detailed mechanisms behind T. gondii-induced pregnancy failure are poorly understood. METHODS: Toxoplasma gondii-infected wild-type (WT) pregnant mice and 2B4 knockout (2B4-/-) pregnant mice were established for in vivo study. Human decidual natural killer (dNK) cells were cultured for in vitro study. Abnormal pregnancy outcomes were observed, and the expression of 2B4, functional molecules (CD69, CD107a, tumor necrosis factor alpha [TNF-α], interferon gamma [IFN-γ]), and signaling molecules (SHP-2, Fyn, p-ERK, p-P38) in dNK cells were detected by flow cytometry, Western blot, reverse transcriptase polymerase chain reaction (RT-PCR), and/or immunofluorescence. The direct interactions (2B4 interacts with SHP-2 and Fyn; SHP-2 interacts with p-P38 and 2B4; Fyn interacts with p-ERK and 2B4) were verified by co-immunoprecipitation (co-IP) in NK-92 cells. RESULTS: Here, results showed that 2B4 was significantly downregulated after T. gondii infection. Subsequently, infected 2B4-/- pregnant mice displayed worse pregnancy outcomes compared with infected WT pregnant mice. Also, increased TNF-α and IFN-γ expression and elevated dNK cell cytotoxicity were found in 2B4-/- pregnant mice during T. gondii infection. In contrast, reduced TNF-α and IFN-γ expression and decreased human dNK cell activity were found following 2B4 activation during T. gondii infection. Interestingly, results showed that 2B4 binds to adaptor SHP-2 or Fyn, which then triggers different signaling pathways to regulate TNF-α and IFN-γ expression in dNK cells during T. gondii infection. Further, SHP-2 binds 2B4 and p-P38 directly after 2B4 activation, which generates an inhibitory signal for TNF-α and IFN-γ in NK-92 cells. In addition, Fyn can bind to 2B4 and p-ERK after activation of 2B4, thereby inhibiting TNF-α and IFN-γ expression in NK-92 cells following T. gondii infection. CONCLUSIONS: These data suggest that 2B4 may be a novel danger-signaling molecule that is implicated in pregnancy failure during T. gondii infection. Unraveling the mechanism by which 2B4 regulates dNK cell activity will provide novel insights to aid our understanding of T. gondii-induced adverse pregnancy outcomes.

The effect of milrinone on mortality in adult patients who underwent CABG surgery: a systematic review of randomized clinical trials with a meta-analysis and trial sequential analysis.

BACKGROUND: As an inodilator, milrinone is commonly used for patients who undergo coronary artery bypass graft (CABG) surgery because of its effectiveness in decreasing the cardiac index and mitral regurgitation. The aim of this study was to perform a systematic review and meta-analysis of existing studies from the past 20 years to evaluate the impact of milrinone on mortality in patients who undergo CABG surgery. METHODS: We performed a systematic literature search on the application of milrinone in patients who underwent CABG surgery in studies published between 1997 and 2017 in BioMed Central, PubMed, EMBASE, and the Cochrane Central Register. The included studies evaluated milrinone groups compared to groups receiving either placebo or standard treatment and further compared the systemic administration. RESULTS: The network meta-analysis included 723 patients from 16 randomized clinical trials. Overall, there was no significant difference in mortality between the milrinone group and the placebo/standard care group when patients underwent CABG surgery. In addition, 9 trials (with 440 randomized patients), 4 trials (with 212 randomized patients), and 10 trials (with 470 randomized patients) reported that the occurrence of myocardial infarction (MI), myocardial ischemia, and arrhythmia was lower in the milrinone group than in the placebo/standard care group. Between the milrinone treatment and placebo/standard care groups, the occurrence of myocardial infarction, myocardial ischemia, and arrhythmia was significantly different. However, the occurrence of stroke and renal failure, the duration of inotropic support (h), the need for an intra-aortic balloon pump (IABP), and mechanical ventilation (h) between these two groups showed no differences. CONCLUSIONS: Based on the current results, compared with placebo, milrinone might be unable to decrease mortality in adult CABG surgical patients but can significantly ameliorate the occurrence of MI, myocardial ischemia, and arrhythmia. These results provide evidence for the further clinical application of milrinone and of therapeutic strategies for CABG surgery. However, along with milrinone application in clinical use, sufficient data from randomized clinical trials need to be collected, and the potential benefits and adverse effects should be analyzed and reevaluated.

MicroRNA-31/184 is involved in transforming growth factor-ß-induced apoptosis in A549 human alveolar adenocarcinoma cells.

AIMS: TGF-ß-induced alveolar epithelial cells apoptosis were involved in idiopathic pulmonary fibrosis (IPF). This study aimed to explore potential targets and mechanisms of IPF. MAIN METHODS: mRNA and microRNA arrays were used to analyze differentially expressed genes and miRNAs. Several essential targets of TGF-ß-SMADs and TGF-ß-PI3K-AKT pathways were detected. KEY FINDINGS: miR-31 and miR-184 expression levels were positively correlated with smad6 and smad2/akt expression levels in IPF patients. TGF-ß could induce miR-31 and suppress miR-184 levels in A549 cells. miR-31 was confirmed to bind to the smad6-3'UTR and functionally suppress its expression. Down-regulated SMAD6 enhanced SMAD2/SMAD4 dimer formation and translocation due to its failure to prevent SMAD2 phosphorylation. In contrast, anti-fibrotic functions of miR-184 were abolished due to TGF-ß directly suppressing miR-184 levels in A549 cells. When A549 was stimulated by TGF-ß combined with or without miR-31 inhibitor/miR-184 mimic, it was showed that depleted miR-31 and/or increased miR-184 significantly ameliorated TGF-ß-induced viability of A549 cells, as well as inhibited the expression of profibrotic factors, MMP7 and RUNX2. SIGNIFICANCE: Inhibiting miR-31 and/or promoting miR-184 protect against TGF-ß-induced fibrogenesis by respectively repressing the TGF-ß-SMAD2 and TGF-ß-PI3K-AKT signaling pathways, implying that miR-31/184 are potential targets and suggesting a new management strategy for IPF.

Toxicity Study of 28-Day Subcutaneous Injection of Arctigenin in Beagle Dogs.

Our previous studies have investigated the systematic pharmacokinetic characteristics, biological activities, and toxicity of arctigenin. In this research, the potential toxicities of arctigenin in beagle dogs were investigated via repeated 28-day subcutaneous injections. Beagle dogs were randomly divided into control, vehicle [polyethylene glycol (PEG)], and arctigenin 6, 20, 60 mg/kg treated groups. The whole experimental period lasted 77 days, including adaptive period (35 days), drug exposure period (animals were treated with saline, PEG, or arctigenin for 28 consecutive days), and recovery period (14 days). Arctigenin injection (60 mg/kg) affected the lymphatic hematopoietic, digestive, urinary, and cardiovascular systems, and all the impact on these tissues resulted in death in five dogs (three female and two male dogs); 20 mg/kg arctigenin injection resulted in toxic reactions of the lymphatic hematopoietic and digestive systems; and 6 mg/kg arctigenin and PEG injection did not lead to significant toxic reactions. Meanwhile, there were no sexual differences of drug exposure and accumulation when dogs underwent different dosages. As stated previously, the toxic target organs of arctigenin administration include lymphatic hematopoietic, digestive (liver and gallbladder), urinary (kidney), and cardiovascular (heart) systems, and the no observed adverse effect level (NOAEL) of arctigenin is less than 6 mg/kg.

Elucidation of Arctigenin Pharmacokinetics and Tissue Distribution after Intravenous, Oral, Hypodermic and Sublingual Administration in Rats and Beagle Dogs: Integration of In Vitro and In Vivo Findings.

Although arctigenin (AG) has diverse bioactivities, such as anti-oxidant, anti-inflammatory, anti-cancer, immunoregulatory and neuroprotective activities, its pharmacokinetics have not been systematically evaluated. The purpose of this work was to identify the pharmacokinetic properties of AG via various experiments in vivo and in vitro. In this research, rats and beagle dogs were used to investigate the PK (pharmacokinetics, PK) profiles of AG with different drug-delivery manners, including intravenous (i.v), hypodermic injection (i.h), and sublingual (s.l) administration. The data shows that AG exhibited a strong absorption capacity in both rats and beagle dogs (absorption rate < 1 h), a high absorption degree (absolute bioavailability > 100%), and a strong elimination ability (t1/2 < 2 h). The tissue distributions of AG at different time points after i.h showed that the distribution of AG in rat tissues is rapid (2.5 h to reach the peak) and wide (detectable in almost all tissues and organs). The AG concentration in the intestine was the highest, followed by that in the heart, liver, pancreas, and kidney. In vitro, AG were incubated with human, monkey, beagle dog and rat liver microsomes. The concentrations of AG were detected by UPLC-MS/MS at different time points (from 0 min to 90 min). The percentages of AG remaining in four species' liver microsomes were human (62 ± 6.36%) > beagle dog (25.9 ± 3.24%) > rat (15.7 ± 9%) > monkey (3.69 ± 0.12%). This systematic investigation of pharmacokinetic profiles of arctigenin (AG) in vivo and in vitro is worthy of further exploration.

N-glycosylation-mutated HCV envelope glycoprotein complex enhances antigen-presenting activity and cellular and neutralizing antibody responses.

BACKGROUND: The development of an efficient vaccine and broadly cross-neutralizing antibodies of hepatitis C virus (HCV) remains a priority. The heavily glycosylated viral envelope glycoprotein E1E2 complex is a candidate vaccine antigen. Bacteria-derived unmethylated CpG DNA, a potent stimulator of immune cells, is important for vaccine research. METHODS: Here, the immunogenicities of wild type (WT) E1E2, five N-glycosylation site mutated E1E2 glycoproteins, and five CpG-coupled E1E2 N-glycosylation mutated glycoproteins were analyzed in BALB/c mice by DNA vaccination using in vivo electroporation. RESULTS: The E1E2 protein expression levels were examined and shown to be unaffected by these N-glycosylation mutations. We found that a CpG-coupled E1-N209D-E2-N430D DNA vaccine (named CpG-E1E2-M4) induced the highest cellular immune response compared to the WT E1E2, CpG-E1E2, and other mutants. Furthermore, the CpG-E1E2-M4 anti-serum effectively neutralized the infection of cell-cultured HCV (HCVcc, genotype 2a)- and HCV pseudo particles (HCVpp, genotypes 1 to 7) to Huh-7.5.1 hepatocytes. Additionally, CpG-E1E2-M4 enhanced the Interleukin-12 (IL-12) production and antigen-presenting activity of CD11c(+) dendritic cells (DCs) by inducing CD4(+) Th1 polarization and the production of perforin and granzyme B (GrB) in CD8(+) T cells. CONCLUSIONS: As our knowledge this is the first study revealing that the naturally poor immunogenicity of E1E2 can be enhanced by the deletion of N-glycans combined with the addition of immune activator CpG by DNA vaccination. GENERAL SIGNIFICANCE: Deletion of N-glycans can enhance viral immunogenicity. The selected CpG-E1E2-M4 mutant is a novel potential HCV DNA vaccine that elicits enhanced CD4(+) Th1 and CD8(+) T cell responses and neutralizing antibody production against HCV infection. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.

Ficolin-2 inhibits hepatitis C virus infection, whereas apolipoprotein E3 mediates viral immune escape.

Human ficolin-2 (L-ficolin/p35) is a lectin-complement pathway activator that is present in normal human plasma and is associated with infectious diseases; however, little is known regarding the roles and mechanisms of ficolin-2 during chronic hepatitis C virus (HCV) infection. In this study, we found that ficolin-2 inhibits the entry of HCV at an early stage of viral infection, regardless of the viral genotype. Ficolin-2 neutralized and inhibited the initial attachment and infection of HCV by binding to the HCV envelope surface glycoproteins E1 and E2, blocking HCV attachment to low-density lipoprotein receptor (LDLR) and scavenger receptor B1, and weakly interfering with CD81 receptor attachment. However, no interference with claudin-1 and occludin receptor attachment was observed. The C-terminal fibrinogen domain (201-313 aa) of ficolin-2 was identified as the critical binding region for the HCV-E1-E2 N-glycans, playing a critical role in the anti-HCV activity. More importantly, we found that apolipoprotein E (ApoE)3, which is enriched in the low-density fractions of HCV RNA-containing particles, promotes HCV infection and inhibits ficolin-2-mediated antiviral activity. ApoE3, but not ApoE2 and ApoE4, blocked the interaction between ficolin-2 and HCV-E2. Our data suggest that the HCV entry inhibitor ficolin-2 is a novel and promising antiviral innate immune molecule, whereas ApoE3 blocks the effect of ficolin-2 and mediates an immune escape mechanism during chronic HCV infection. HCV may be neutralized using compounds directed against the lipoprotein moiety of the viral particle, and ApoE3 may be a new target to combat HCV infection.

Ficolins and infectious diseases.

Ficolins are serum complement lectins, with a structure similar to mannose-binding lectin (MBL) and lung surfactant protein (SP)-A and SP-D. Ficolins activate the lectin complement system and play important roles in host innate immunity. Ficolins are members of the collectin family of proteins, which act as pattern recognition receptors (PRRs). They are soluble oligomeric defense proteins with lectin-like activity, and are able to recognize pathogen-associated molecular patterns (PAMPs), which are carbohydrate molecules on the surface of pathogens, and of apoptotic, necrotic, and malignant cells. Upon binding to their specific PAMPs, ficolins may trigger activation of the immune system either (1) by initiating activation of complement via the lectin pathway, (2) by a primitive type of opsonophagocytosis, or (3) by stimulating secretion of the inflammatory cytokines interferon (IFN)-Γ, interleukin (IL)-17, IL-6, and tumor necrosis factor (TNF)-α, and production of nitric oxide (NO) by macrophages, thus limiting the infection and concurrently orchestrating the subsequent adaptive immune response. Recently, a number of reports have shown that dysfunction or abnormal expression of ficolins may play crucial roles in viral and bacterial diseases and in inflammation. This review summarizes the reports on the roles of ficolins in the infectious diseases, and provides insight into ficolins as novel innate immune therapeutic options to treat these diseases.

Knockdown of core 1 beta 1, 3-galactosyltransferase prolongs skin allograft survival with induction of galectin-1 secretion and suppression of CD8+ T cells: T synthase knockdown effects on galectin-1 and CD8+ T cells.

Core 1 beta 1,3-galactosyltransferase also known as T-antigen-synthase or T-synthase is a key enzyme for the synthesis of the common core 1 O-glycan structure (T-antigen). Although T-synthase is known to be important in human immune-related diseases, the effects of T-synthase and T-antigen on host immune responses remain poorly defined. In this study, a T-synthase-specific short hairpin RNA (shRNA) was transfected into murine colon carcinoma CT26 cells or mouse muscle tissues via intramuscular electroporation to assess the effects of T-synthase on T cells and cytokines. T-synthase knockdown significantly induced galectin-1 secretion both in vivo and in vitro and strongly enhanced Th2 cytokine (IL-10 and IL-4) production in vivo. Further, the increased production of galectin-1 induced by T-synthase knockdown promoted CD8(+) T-cell apoptosis, which, when combined with the increased production of CD4(+) T cell-derived Th2 cytokines prolonged the survival of skin allografts in mice. Our data suggest core 1 beta 1,3-galactosyltransferase-shRNA could serve not only as a useful tool in organ transplantation but also as a powerful tool for investigating O-glycans and glycoprotein synthesis and function.

Melanoma B16-F1 cells coated with fusion protein of mouse calreticulin and virus G-protein coupled receptor induced the antitumor immune response in Balb/C mice.

In apoptotic progress of tumor cells stimulated by special agents, the calreticulin (CRT) was relocated from endoplasmic reticulum onto the cell surface. When used as cellular antigen to immunize experimental animals, these CRT-coated apoptotic tumor cells could initiate effective anti-tumor immunoresponse against homologous tumor cells, indicating the value of CRT in anti-tumor immunotherapy. In order to develop an universal technique that could make CRT-coating more efficiently in the tumor cells, in this study, a mouse CRT recombinant gene with virus G-protein coupled receptor (vGPCR) was constructed and cloned into vector pcDNA3.1(+). When resulted plasmid pcDNA3.1(+)-mCRT/ vGPCR was stably transfected into the mouse melanoma B16-F1 cells, the mCRT-vGPCR recombinant protein was synthesized. With the membrane-locating ability of vGPCR in the recombinant protein, mCRT-vGPCR was carried onto the surface of B16-F1 cells efficiently. Overexpression of mCRT-vGPCR on the cell surface could enhance the phagocytosis of B16-F1 by macrophages in vitro. When mCRT-vGPCR coated B16-F1 cells were used as a cell-antigen to immunize mice, the specific anti-tumor immune response against the homologous tumor cells was initiated efficiently. Our data in this study may provide a new possibility for CRT-mediated tumor immune prevention and treatment.

Mitoxantrone-mediated apoptotic B16-F1 cells induce specific anti-tumor immune response.

In the process of cell apoptosis induced by specific reagents, calreticulin (CRT) in endoplasmic reticulum is transferred and coated onto the cell membrane. As a sort of specific ligand, the CRT on the surface of apoptotic cells could mediate recognition and clearance of apoptotic cells by phagocytes. In this research we discovered that mitoxantrone could induce apoptosis of mouse melonoma B16-F1 tumor cells, accompanied by the membrane translocation and coating of CRT. When mitoxantrone-treated B16-F1 cells were used as antigen to inoculate mice, the mice acquired an ability to suppress proliferation of homologous tumor cells. Splenocytes from these mice showed an increased cytolytic effect on homologous B16-F1 cells but no such effect on non-homologous H22 tumor cells. All these results suggested that mitoxantrone-treated apoptotic B16-F1 cells could be used as a sort of cell vaccine to initiate effective anti-tumor immunoresponse in mice.

[Prokaryotic expression and polyclonal antibody preparation of human spermine oxidase].

AIM: To prepare recombinant human spermine oxidase (SMO) and polyclonal antibody against human SMO by gene recombination techniques. METHODS: Human SMO cDNA was amplified from total RNA of A549 cells through reverse transcription PCR. The cDNA was then cloned into pET-15b to construct SMO prokaryotic expression vector. After transforming, the vector was induced to express recombinant SMO by IPTG in E.coli BL21 (DE(3)). Recombinant SMO was purified by Ni-NTA resin under denaturing condition and then was dialyzed to renature. The enzyme activity of recombinant SMO was analyzed by chemical fluorescent method. SMO polyclonal antibody was prepared by using recombinant human SMO protein purified by polyacrylamide gel electrophoresis as antigen to inoculate rabbit intradermally. The titer and specificity of anti-sera were determined by ELISA, Western blot and Immune Cell Chemistry. RESULTS: Purified and dialyzed recombinant human SMO has the specificity of oxidizing the spermine. The polyclonal antibody has high titer and specificity against human SMO. CONCLUSION: This research established a method for prokaryotic expression, purification and polyclonal antibody preparation of human SMO. The method lays a foundation for the future functional research of SMO.