Establishment of a Multiplex Detection Method for Common Bacteria in Blood Based on Human Mannan-Binding Lectin Protein-Conjugated Magnetic Bead Enrichment Combined with Recombinase-Aided PCR Technology.

Objective: Recombinase-aided polymerase chain reaction (RAP) is a sensitive, single-tube, two-stage nucleic acid amplification method. This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Acinetobacter baumannii (AB) in the bloodstream based on recombinant human mannan-binding lectin protein (M1 protein)-conjugated magnetic bead (M1 bead) enrichment of pathogens combined with RAP. Methods: Recombinant plasmids were used to evaluate the assay sensitivity. Common blood influenza bacteria were used for the specific detection. Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR (M-RAP) and quantitative PCR (qPCR) assays. Kappa analysis was used to evaluate the consistency between the two assays. Results: The M-RAP method had sensitivity rates of 1, 10, and 1 copies/µL for the detection of SA, PA, and AB plasmids, respectively, without cross-reaction to other bacterial species. The M-RAP assay obtained results for < 10 CFU/mL pathogens in the blood within 4 h, with higher sensitivity than qPCR. M-RAP and qPCR for SA, PA, and AB yielded Kappa values of 0.839, 0.815, and 0.856, respectively ( P < 0.05). Conclusion: An M-RAP assay for SA, PA, and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.

[Effect of lime water processing of Pinelliae Rhizoma Praeparatum on toxic component lectin protein].

The present study investigated the effect of immersion in the excipient lime water on the toxic component lectin protein and explained the scientific connotation of lime water detoxication during the processing of Pinelliae Rhizoma Praeparatum. Western blot was used to investigate the effects of immersion in lime water with different pH(pH 10, 11, and 12.4), saturated sodium hydroxide, and sodium bicarbonate solution on the content of lectin protein. The protein compositions of the supernatant and the precipitate after immersing lectin protein in lime water of different pH were determined by the SDS-PAGE method combined with the silver staining technique. The MALDI-TOF-MS/MS technique was used to detect the molecular weight distribution of peptide fragments in the supernatant and precipitate after immersing lectin protein in lime water of different pH, and circular dichroism spectroscopy was used to detect the ratio changes in the secondary structure of lectin protein during the immersion. The results showed that immersion in lime water at pH>12 and saturated sodium hydroxide solution could significantly reduce the content of lectin protein, while immersion in lime water at pH<12 and sodium bicarbonate solution had no significant effect on lectin protein content. The corresponding lectin protein bands and molecular ion peaks were not detected at the 12 kDa position in the supernatant and precipitate after immersing the lectin protein in lime water at pH>12, which was attributed to the fact that lime water immersion at pH>12 could significantly change the ratio of the secondary structure of lectin protein, resulting in irreversible denaturation, while lime water immersion at pH<12 did not change the ratio of the secondary structure of lectin protein. Therefore, pH>12 was the key condition for the detoxication of lime water during the processing of Pinelliae Rhizoma Praeparatum. Lime water immersion at pH>12 could cause irreversible denaturation of lectin protein, resulting in a significant decrease in the inflammatory toxicity of Pinelliae Rhizoma Praeparatum, which played a key role in detoxification.

Identification of a type II LacNAc specific binding lectin CMRBL from Cordyceps militaris.

The Cordyceps militaris gene CCM_03832 encodes a ricin-B like lectin. The gene was cloned and expressed in Escherichia coli, and its protein product, named CMRBL (C. militaris ricin-B like lectin), was purified by galactose affinity chromatography. Of nine different sources of erythrocytes, CMRBL showed only specific hemagglutinating activity against rat and rabbit erythrocytes with titers of 22 and 28, respectively. Glycan array analyses by the Consortium for Functional Glycomics showed that CMRBL possesses very high specific binding activity of glycans terminated with type II LacNAc (non-reducing Galß1-4GlcNAc). Compared with other well-known Gal-terminated binding lectins such as Erythrina cristagalli agglutinin, Ricinus communis agglutinin, and Jacalin, CMRBL showed better binding specificity to type II LacNAc compared the other lectins. CMRBL showed lowest binding activity to ZR-75-30 and MDA-MB-468 cell lines among five tested cell lines (H22, THP-1, MDA-MB-231, ZR-75-30, and MDA-MB-468 cells). Transfection of type II LacNAc main galactosyltransferase B4GALT3 to ZR-75-30 significantly improved CMRBL binding activity compared with control. CMRBL was also applied for testing the type II LacNAc modification of Etanercept successfully. Our data suggest that CMRBL would be a useful tool to recognize type II LacNAc, especially distinguish type II from other galactose-terminated glycans in glycan biology research.

Effect of lime water processing of Pinelliae Rhizoma Praeparatum on toxic component lectin protein / 中国中药杂志

The present study investigated the effect of immersion in the excipient lime water on the toxic component lectin protein and explained the scientific connotation of lime water detoxication during the processing of Pinelliae Rhizoma Praeparatum. Western blot was used to investigate the effects of immersion in lime water with different pH(pH 10, 11, and 12.4), saturated sodium hydroxide, and sodium bicarbonate solution on the content of lectin protein. The protein compositions of the supernatant and the precipitate after immersing lectin protein in lime water of different pH were determined by the SDS-PAGE method combined with the silver staining technique. The MALDI-TOF-MS/MS technique was used to detect the molecular weight distribution of peptide fragments in the supernatant and precipitate after immersing lectin protein in lime water of different pH, and circular dichroism spectroscopy was used to detect the ratio changes in the secondary structure of lectin protein during the immersion. The results showed that immersion in lime water at pH>12 and saturated sodium hydroxide solution could significantly reduce the content of lectin protein, while immersion in lime water at pH<12 and sodium bicarbonate solution had no significant effect on lectin protein content. The corresponding lectin protein bands and molecular ion peaks were not detected at the 12 kDa position in the supernatant and precipitate after immersing the lectin protein in lime water at pH>12, which was attributed to the fact that lime water immersion at pH>12 could significantly change the ratio of the secondary structure of lectin protein, resulting in irreversible denaturation, while lime water immersion at pH<12 did not change the ratio of the secondary structure of lectin protein. Therefore, pH>12 was the key condition for the detoxication of lime water during the processing of Pinelliae Rhizoma Praeparatum. Lime water immersion at pH>12 could cause irreversible denaturation of lectin protein, resulting in a significant decrease in the inflammatory toxicity of Pinelliae Rhizoma Praeparatum, which played a key role in detoxification.

[Preparation of monoclonal antibodies against Pinellia ternata lectin protein and establishment of double-antibody sandwich ELISA].

To determine the content of endogenous toxic substance Pinellia ternata lectin(PTL) protein in Pinelliae Rhizoma and the related processed products, this study prepared specific monoclonal antibodies against PTL by hybridoma cell technology, and established a quantitative double-antibody sandwich enzyme linked immunosorbent assay(ELISA) for PTL antigen. The detection conditions were 2.5 µg·mL~(-1) working concentration of the captured antibody and 1∶450 of the dilution multiple of detected antibody. The coating condition was staying overnight at 4 ℃. The blocking time and incubation times of antigen and detected antibody were all 90 minutes. The incubation time of horseradish peroxidase conjugated streptavidin-horseradish peroxidase(SA-HRP) was 15 minutes. The quantitative limit of the method for PTL antigen was 0.375 ng·mL~(-1). The linear range was 75.000-4 800.000 pg·mL~(-1), and R~2=0.997 1. The recovery rate was 90.0%-110.0%, and the variation coefficients of intra-test and inter-test precision were 2.0%-3.0% and 2.0%-8.5%.The content of PTL in three batches of Pinelliae Rhizoma and the related processed products was determined by the method, and the average content of PTL in Pinelliae Rhizoma was 35.42 mg·g~(-1). The average content of PTL in Pinelliae Rhizoma Praeparatum Cum Alumine, Pinelliae Rhizoma Praeparatum, and Pinelliae Rhizoma Praeparatum Cum Zingibere Et Alumine were 1.15 mg·g~(-1), 16.53 µg·g~(-1), and 122.63 ng·g~(-1), respectively, indicating that the content of PTL decreased significantly after processing. The quantitative double-antibody sandwich ELISA for PTL antigen established in this paper had good linearity, sensitive response, and high accuracy, which provided a simple and effective monitoring method for the detection of PTL content in the processing of Pinelliae Rhizoma.

[Effect of Pinelliae Rhizoma processed with lime and licorice on toxic lectin protein].

The present study was aimed to investigate the effect of lime and licorice processing of Pinelliae Rhizoma on its toxic lectin protein and clarify the scientific detoxification connotation of lime and licorice processing of Pinelliae Rhizoma. Western blot was used to semi-quantitatively analyze the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum. Raw products and lectin were treated by soaking in licorice juice, lime solution or mixture solution of these two to investigate the different processing time on the content of toxic lectin protein. SDS-PAGE gel electrophoresis was used to analyze the changes of lectin protein bands in the solution and precipitates before and after processing. MALDI-TOF technology was used to qualitatively analyze and compare the protein molecular weight before and after processing. The results showed that the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum were 5.01% and 0.04% respectively, indicating that processing could significantly reduce the content of active lectin in raw products. The results also showed that the content of lectin in raw drugs decreased significantly after soaking in lime solution for one day or in licorice juice for three day, and the effect was greatest in mixture solution. Qualitative analysis showed that after being treated by soaking in lime solution, the lectin protein was decomposed into small peptide segments, while after being treated by soaking in licorice juice, the lectin protein was denatured and precipitated. The structure of lectin protein in Pinelliae Rhizoma was broken after being processed with licorice juice and lime solution, which significantly reduced the content of toxic lectinprotein. This is one of the detoxification mechanisms of Pinelliae Rhizoma processing.

Effect of Pinelliae Rhizoma processed with lime and licorice on toxic lectin protein / 中国中药杂志

The present study was aimed to investigate the effect of lime and licorice processing of Pinelliae Rhizoma on its toxic lectin protein and clarify the scientific detoxification connotation of lime and licorice processing of Pinelliae Rhizoma. Western blot was used to semi-quantitatively analyze the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum. Raw products and lectin were treated by soaking in licorice juice, lime solution or mixture solution of these two to investigate the different processing time on the content of toxic lectin protein. SDS-PAGE gel electrophoresis was used to analyze the changes of lectin protein bands in the solution and precipitates before and after processing. MALDI-TOF technology was used to qualitatively analyze and compare the protein molecular weight before and after processing. The results showed that the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum were 5.01% and 0.04% respectively, indicating that processing could significantly reduce the content of active lectin in raw products. The results also showed that the content of lectin in raw drugs decreased significantly after soaking in lime solution for one day or in licorice juice for three day, and the effect was greatest in mixture solution. Qualitative analysis showed that after being treated by soaking in lime solution, the lectin protein was decomposed into small peptide segments, while after being treated by soaking in licorice juice, the lectin protein was denatured and precipitated. The structure of lectin protein in Pinelliae Rhizoma was broken after being processed with licorice juice and lime solution, which significantly reduced the content of toxic lectinprotein. This is one of the detoxification mechanisms of Pinelliae Rhizoma processing.

Expression, purification and induction of apoptosis of gastric cancer cells by salvia miltiorrhiza lectin in vitro / 医学研究生学报

Objective　The active protein of traditional Chinese medicine has anti-tumor effect, and salvia miltiorrhiza is an important anti-tumor traditional Chinese medicine. Here, the effect of Salvia miltiorrhiza lectin protein (SMLP) on the apoptosis of gastric cancer cells was studied.　Methods　SMLP expressed and purified from prokaryotic cells was used to treat the gastric cancer cells SGC-7901. The experiment was divided into the control group (untreated) and the SMLP treatment group (final concentration of 10 μmol / L of SMLP was treated for 24 h). Real-time RT-PCR and Western blot were used to detect the changes of apoptosis gene expression. Flow cytometry and Hoechst staining were applied to detect the apoptotic status. Caspase-3 and Caspase-9 activity assay kits were used to detect the apoptotic level.　Results　The result of RT-PCR showed that the mRNA level of Bax in the SMLP treatment group was significantly higher than in the control group (1.00±0.12 vs 0.67±0.10）(P<0.05). After treatment with SMLP to gastric cancer cells, the activity and expression level of cleaved Caspase-3 and Caspase-9 were increased significantly compared with the control group (P<0.05). The cell nucleus in the control group was bigger and rounder, with smooth surface and uniform staining, whilst in the SMLP-treated group, the cell nucleus became deeper with pyknosis, representing typical morphological characteristics of apoptosis. The early apoptosis level in the control group was 6.55%, and the SMLP treatment group reached 10.18%, showing an increase in the level of apoptosis.　Conclusion　SMLP expressed and purified in vitro can promote the apoptosis of gastric cancer cells, which is of great significance for further revealing the function of plant lectin and investigating the anti-tumor effect on the protein of traditional Chinese medicine.

Synthesis of Gold Functionalised Nanoparticles with the Eranthis hyemalis Lectin and Preliminary Toxicological Studies on Caenorhabditis elegans.

The lectin found in the tubers of the Winter Aconite (Eranthis hyemalis) plant (EHL) is a Type II Ribosome Inactivating Protein (RIP). Type II RIPs have shown anti-cancer properties and have great potential as therapeutic agents. Similarly, colloidal gold nanoparticles are successfully used in biomedical applications as they can be functionalised with ligands with high affinity and specificity for target cells to create therapeutic and imaging agents. Here we present the synthesis and characterization of gold nanoparticles conjugated with EHL and the results of a set of initial assays to establish whether the biological effect of EHL is altered by the conjugation. Gold nanoparticles functionalised with EHL (AuNPs@EHL) were successfully synthesised by bioconjugation with citrate gold nanoparticles (AuNPs@Citrate). The conjugates were analysed by UV-Vis spectroscopy, Dynamic Light Scattering (DLS), Zeta Potential analysis, and Transmission Electron Microscopy (TEM). Results indicate that an optimal functionalisation was achieved with the addition of 100 µL of EHL (concentration 1090 ± 40 µg/mL) over 5 mL of AuNPs (concentration [Au°] = 0.8 mM). Biological assays on the effect of AuNPs@EHL were undertaken on Caenorhabditis elegans, a free-living nematode commonly used for toxicological studies, that has previously been shown to be strongly affected by EHL. Citrate gold nanoparticles did not have any obvious effect on the nematodes. For first larval stage (L1) nematodes, AuNPs@EHL showed a lower biological effect than EHL. For L4 stage, pre-adult nematodes, both EHL alone and AuNPs@EHL delayed the onset of reproduction and reduced fecundity. These assays indicate that EHL can be conjugated to gold nanoparticles and retain elements of biocidal activity.

Mutations in fetal genes involved in innate immunity and host defense against microbes increase risk of preterm premature rupture of membranes (PPROM).

BACKGROUND: Twin studies have revealed a significant contribution of the fetal genome to risk of preterm birth. Preterm premature rupture of membranes (PPROM) is the leading identifiable cause of preterm delivery. Infection and inflammation of the fetal membranes is commonly found associated with PPROM. METHODS: We carried out whole exome sequencing (WES) of genomic DNA from neonates born of African-American mothers whose pregnancies were complicated by PPROM (76) or were normal term pregnancies (N = 43) to identify mutations in 35 candidate genes involved in innate immunity and host defenses against microbes. Targeted genotyping of mutations in the candidates discovered by WES was conducted on an additional 188 PPROM cases and 175 controls. RESULTS: We identified rare heterozygous nonsense and frameshift mutations in several of the candidate genes, including CARD6, CARD8, DEFB1, FUT2, MBL2, NLP10, NLRP12, and NOD2. We discovered that some mutations (CARD6, DEFB1, FUT2, MBL2, NLRP10, NOD2) were present only in PPROM cases. CONCLUSIONS: We conclude that rare damaging mutations in innate immunity and host defense genes, the majority being heterozygous, are more frequent in neonates born of pregnancies complicated by PPROM. These findings suggest that the risk of preterm birth in African-Americans may be conferred by mutations in multiple genes encoding proteins involved in dampening the innate immune response or protecting the host against microbial infection and microbial products.

Association between TLR2/TLR4 gene polymorphisms and COPD phenotype in a Greek cohort.

BACKGROUND: Considering that the innate immune system plays a pivotal role in the pathogenesis of chronic obstructive pulmonary disease (COPD), we hypothesized that functional single-nucleotide polymorphisms (SNPs) of innate immune genes affect the disease phenotype and prognosis. AIM: To elucidate the contribution of common functional TLR2 and TLR4 SNPs and genotypic deficiency of the mannose-binding lectin (MBL) protein, both as single parameters and in combination, in Greek COPD patients. RESULTS: In a cohort of 114 Greek COPD patients, we confirmed that the presence of TLR4-D299G or TLR4-T399I SNPs was significantly associated with an earlier COPD stage (p = 0.003 and p = 0.009, respectively). In comparison, the absence of any analyzed polymorphism, including those of TLR2-R753Q and genotypic MBL deficiency, was significantly associated with a more severe disease phenotype, characterized by more frequent exacerbations (p = 0.045). CONCLUSION: Our findings support the notion that the presence of innate immune SNPs, such as functional polymorphisms of TLRs along with MBL deficiency, might exert a protective effect on the COPD phenotype, similar with other immune-mediated disorders.

Protein regulation and Apoptotic induction in human breast carcinoma cells (MCF-7) through lectin from G. beauts.

Lectins are proteins that show a variety of biological activities. Nevertheless, information on lectin from Gluttonous beauts and their anticancer activities are very limited. In this study, we purified a lectin from hemolymph of G. beauts and identified its molecular weight to be 66kDa. The effect of lectin at different concentrations (µg/mL) on the cell growth and apoptosis were evaluated against MCF-7 and MCF-10A cells, whereas cytotoxicity to the MCF-7 cells mediated by lectin was observed and the mechanism of action of the lectin in including apoptosis in cancer cells via the intrinsic pathway was also proposed. The MCF-7 cells were employed for in vitro studies on cytotoxicity, induction of apoptosis and apoptotic DNA fragmentation. In MCF-10A cells lectin did not show any adverse effect even at higher concentration. Cell cycle analysis also showed a significant cell cycle arrest on selected cells after lectin treatment. Western blotting suggested that lectin up regulates the apoptotic protein expression in MCF-7 cells while it down regulates the level of Bcl-2 expression.

Vixapatin (VP12), a c-type lectin-protein from Vipera xantina palestinae venom: characterization as a novel anti-angiogenic compound.

A C-type lectin-like protein (CTL), originally identified as VP12 and lately named Vixapatin, was isolated and characterized from Israeli viper Vipera xantina palestinae snake venom. This CTL was characterized as a selective α2ß1 integrin inhibitor with anti-melanoma metastatic activity. The major aim of the present study was to prove the possibility that this protein is also a potent novel anti-angiogenic compound. Using an adhesion assay, we demonstrated that Vixapatin selectively and potently inhibited the α2 mediated adhesion of K562 over-expressing cells, with IC(50) of 3 nM. 3 nM Vixapatin blocked proliferation of human dermal microvascular endothelial cells (HDMEC); 25 nM inhibited collagen I induced migration of human fibrosarcoma HT-1080 cells; and 50 nM rat C6 glioma and human breast carcinoma MDA-MB-231 cells. 1 µM Vixapatin reduced HDMEC tube formation by 75% in a Matrigel assay. Furthermore, 1 µM Vixapatin decreased by 70% bFGF-induced physiological angiogenesis, and by 94% C6 glioma-induced pathological angiogenesis, in shell-less embryonic quail chorioallantoic membrane assay. Vixapatin's ability to inhibit all steps of the angiogenesis process suggest that it is a novel pharmacological tool for studying α2ß1 integrin mediated angiogenesis and a lead compound for the development of a novel anti-angiogenic/angiostatic/anti-cancer drug.