Hemagglutinating Activity Research Articles

Epidemic of wild-origin H1NX avian influenza viruses in Anhui, China

BackgroundAs the natural hosts of avian influenza viruses (AIVs), aquatic and migratory birds provide a gene pool for genetic transfer among species and across species, forming transient “genome constellations.” This work describes the phylogenetic dynamics of H1NX based on the complete molecular characterization of eight genes of viruses that were collected from 2014 to 2015 in Anhui Province, China.MethodsHemagglutination and hemagglutination inhibition tests were used to determine the hemagglutination (HA) activity of the HA subtypes. The entire genomes of the viruses were sequenced on an ABI PRISM 3500xl DNA Analyzer. The sequences were genetically analysed to study their genetic evolution using DNASTAR and MEGA 6. The pathogenic effects of the viruses were evaluated using mouse infection models.ResultsSeven strains of the H1 subtype avian influenza virus were isolated. Phylogenetic analysis indicated natural recombination of the H1 influenza viruses between the Eurasian lineage and the North American lineage. Some genes had high sequence identity with A/bean goose/Korea/220/2011(H9N2), which is a typical case involving viral reassortment between the Eurasian lineage and the North American lineage. The results of infection experiments in mice showed that the viruses could acquire the ability to multiply in mouse respiratory organs without adaptation.ConclusionsThese findings suggest that continued surveillance of wild birds, particularly migratory birds, is important to provide early warning of possible H1 influenza epidemics and to understand the ecology of the virus.

Effect of GlcNAc-, Man- and Gal-Specific Lectins of the Cytosol, Nuclear Membrane, and Nuclear Matrix of Calf Brain Cortex on Proliferation Activity of Peripheral Blood Lymphocyte.

We studied the effect of GlcNAc-, Man-, and Gal-specific lectins isolated from cell cytosol, nuclear membrane, and nuclear matrix of calf brain cortex, lyophilized, and stored for 5 years on proliferation activity of human peripheral blood lymphocytes and on hemagglutination activity of trypsinized rabbit erythrocytes. Human peripheral blood lymphocytes treated lyophilized lectins demonstrated lower proliferation activity than lymphocytes treated with concanavalin A (positive control), but higher than control lymphocytes (incubated with saline). Lectins produced no effect on hemagglutination activity.

Phytochemical Analysis of Muntingia calabura Extracts Possessing Anti-Microbial and Anti-Fouling Activities

The present study was carried out to determine the possible antifouling and anti microbial activity of plant extracts prepared from Muntingia calabura and phytochemical screening was demonstrated. The extracts from the following plant parts like stem, leaves, fruits, flower and stems were prepared in different aqueous solvents like ethanol, methanol, acetone, acetonitrile and water. The highest antimicrobial potentials were observed for the methanolic extracts against K. pneumonia, B. subtilis, B. megaterium and P. aeruginosa. Its efficacy was comparable to the standard drug, ampicillin. Significant amount of tannins, alkaloids, steroids and flavonoids were found. Interestingly, the present study showed anti fouling effect against pathogenic biofilm forming bacteria. These extracts also contain high hemagglutination activity. The present study provides evidence that solvent extract of M. calabura contains medicinally important bioactive compounds and this justifies the use of plant species as traditional medicine for treatment of various diseases.

A Chitin-binding Protein Purified from Moringa oleifera Seeds Presents Anticandidal Activity by Increasing Cell Membrane Permeability and Reactive Oxygen Species Production.

Candida species are opportunistic pathogens that infect immunocompromised and/or immunosuppressed patients, particularly in hospital facilities, that besides representing a significant threat to health increase the risk of mortality. Apart from echinocandins and triazoles, which are well tolerated, most of the antifungal drugs used for candidiasis treatment can cause side effects and lead to the development of resistant strains. A promising alternative to the conventional treatments is the use of plant proteins. M. oleifera Lam. is a plant with valuable medicinal properties, including antimicrobial activity. This work aimed to purify a chitin-binding protein from M. oleifera seeds and to evaluate its antifungal properties against Candida species. The purified protein, named Mo-CBP2, represented about 0.2% of the total seed protein and appeared as a single band on native PAGE. By mass spectrometry, Mo-CBP2 presented 13,309 Da. However, by SDS-PAGE, Mo-CBP2 migrated as a single band with an apparent molecular mass of 23,400 Da. Tricine-SDS-PAGE of Mo-CBP2 under reduced conditions revealed two protein bands with apparent molecular masses of 7,900 and 4,600 Da. Altogether, these results suggest that Mo-CBP2 exists in different oligomeric forms. Moreover, Mo-CBP2 is a basic glycoprotein (pI 10.9) with 4.1% (m/m) sugar and it did not display hemagglutinating and hemolytic activities upon rabbit and human erythrocytes. A comparative analysis of the sequence of triptic peptides from Mo-CBP2 in solution, after LC-ESI-MS/MS, revealed similarity with other M. oleifera proteins, as the 2S albumin Mo-CBP3 and flocculating proteins, and 2S albumins from different species. Mo-CBP2 possesses in vitro antifungal activity against Candida albicans, C. parapsilosis, C. krusei, and C. tropicalis, with MIC50 and MIC90 values ranging between 9.45–37.90 and 155.84–260.29 μM, respectively. In addition, Mo-CBP2 (18.90 μM) increased the cell membrane permeabilization and reactive oxygen species production in C. albicans and promoted degradation of circular plasmid DNA (pUC18) from Escherichia coli. The data presented in this study highlight the potential use of Mo-CBP2 as an anticandidal agent, based on its ability to inhibit Candida spp. growth with apparently low toxicity on mammalian cells.

Can γ-radiation modulate hemagglutinating and anticoagulant activities of PpyLL, a lectin from Phthirusa pyrifolia?

Blood coagulation and platelet-dependent primary homeostasis are important defense mechanisms against bleeding and novel inhibitors have been researched to obtain pharmacological and clinical applications. In this work, the PpyLL, a lectin obtained from Phthirusa pyrifolia, was characterized in terms of its molecular structure and biological functions (anticoagulant, antiplatelet agreggation and hemagglutinating activities) in presence or absence of Gamma radiation exposure. Results revealed a lectin with secondary-structure content by approximately 49% of β-sheet, 20% of β-turn and 31% of disordered structure. Irradiation effect demonstrated possible different sites of function by lectin on anticoagulant and hemagglutinating activities, once a decrease about 80% was observed when compared the activities under 0.5kGy of exposition to gamma radiation. An emphatic discussion about the use of gamma radiation as a possible modulator of the lectin activity was made, and once the ionizing radiation affected differently the anticoagulation and hemagglutinating activities, we speculated that the results are determined by selective molecular damages in different binding sites. PpyLL biological activities and gamma radiation modulation could be considered for future researches in biomedical field aiming possible medical applications.

Characterization and function of a tachylectin 5-like immune molecule in Penaeus monodon

Tachylectin5A and its homolog, tachylectin5B both contain a fibrinogen-related domain (FReD) and have been studied in horseshoe crabs, Tachypleus tridentatus and Carcinoscorpius rotundicauda and shown to be involved in host defense. Here, we demonstrate the presence of tachylectin5-like genes in shrimp, Penaeus monodon, designated as Penlectin5-1 (PL5-1) and Penlectin5-2 (PL5-2), which both contain a signal peptide and a single FReD with an acetyl group and a calcium binding sites and they are both structurally similar to horseshoe crab tachylectin/carcinolectin5. The PL5-1and PL5-2 transcript were expressed in various shrimp tissues in normal shrimp, and their expression was upregulated in tissues such as hemocytes and hindgut following challenge with pathogenic Vibrio harveyi. The PL5-2 protein was detected in various tissues as well as in cell-free hemolymph. The biological function of the PL5-2 protein is to recognize some Gram-positive and Gram-negative bacteria regardless whether they are non-pathogenic or pathogenic. They have hemagglutination activity on human erythrocyte and bacterial agglutination activity to both Gram negative and Gram positive bacteria. Possible binding sites of PL5-2 to bacteria could be at the N-acetyl moiety of the GlcNAc-MurNAc cell wall of the peptidoglycan since the binding could be inhibited by GlcNAc or GalNAC. The presence of PL5-2 protein in both circulating hemolymph and intestine, where host and microbes are usually interacting, may suggest that the physiological function of shrimp tachylectin-like proteins is to recognize and bind to invading bacteria to immobilize and entrap these microbes and subsequently clear them from circulation and the host body, and probably to control and maintain the normal flora in the intestine.

Isolation, Amino Acid Sequences, and Plausible Functions of the Galacturonic Acid-Binding Egg Lectin of the Sea Hare Aplysia kurodai.

Egg lectins occur in a variety of animals ranging from mollusks to vertebrates. A few examples of molluscan egg lectins have been reported, including that of the sea hare Aplysia kurodai; however, their biological functions in the egg remain unclarified. We report the isolation, determination of primary structure, and possible functions of A. kurodai lectin (AKL) from the egg mass of A. kurodai. We obtained AKL as an inseparable mixture of isoproteins with a relative molecular mass of approximately 32 kDa by affinity purification. The hemagglutinating activity of AKL against rabbit erythrocytes was inhibited most potently by galacturonic acid and moderately by xylose. Nucleotide sequencing of corresponding cDNA obtained by rapid amplification of cDNA ends (RACE) allowed us to deduce complete amino acid sequences. The mature polypeptides consisted of 218- or 219-amino acids with three repeated domains. The amino acid sequence had similarities to hypothetical proteins of Aplysia spp., or domain DUF3011 of uncharacterized bacterial proteins. AKL is the first member of the DUF3011 family whose function, carbohydrate recognition, was revealed. Treatment of the egg with galacturonic acid, an AKL sugar inhibitor, resulted in deformation of the veliger larvae, suggesting that AKL is involved in organogenesis in the developmental stage of A. kurodai.

Investigation of Echinacea purpurea Root Proteins with Hemagglutinating Activity

Proteins were extracted and fractionated from Echinacea purpurea L. (Moench) (purple coneflower) roots, to evaluate their hemagglutinating activity. Our data suggests that the ~ 25 kDa glycosylated protein is responsible for the hemagglutinating activity and might be worth for its investigation for other biological activities.

Neuraminidase-mediated haemagglutination of recent human influenza A(H3N2) viruses is determined by arginine 150 flanking the neuraminidase catalytic site.

Over the last decade, an increasing proportion of circulating human influenza A(H3N2) viruses exhibited haemagglutination activity that was sensitive to neuraminidase inhibitors. This change in haemagglutination as compared to older circulating A(H3N2) viruses prompted an investigation of the underlying molecular basis. Recent human influenza A(H3N2) viruses were found to agglutinate turkey erythrocytes in a manner that could be blocked with either oseltamivir or neuraminidase-specific antisera, indicating that agglutination was driven by neuraminidase, with a low or negligible contribution of haemagglutinin. Using representative virus recombinants it was shown that the haemagglutinin of a recent A(H3N2) virus indeed had decreased activity to agglutinate turkey erythrocytes, while its neuraminidase displayed increased haemagglutinating activity. Viruses with chimeric and mutant neuraminidases were used to identify the amino acid substitution histidine to arginine at position 150 flanking the neuraminidase catalytic site as the determinant of this neuraminidase-mediated haemagglutination. An analysis of publicly available neuraminidase gene sequences showed that viruses with histidine at position 150 were rapidly replaced by viruses with arginine at this position between 2005 and 2008, in agreement with the phenotypic data. As a consequence of neuraminidase-mediated haemagglutination of recent A(H3N2) viruses and poor haemagglutination via haemagglutinin, haemagglutination inhibition assays with A(H3N2) antisera are no longer useful to characterize the antigenic properties of the haemagglutinin of these viruses for vaccine strain selection purposes. Continuous monitoring of the evolution of these viruses and potential consequences for vaccine strain selection remains important.

Characterization of hemagglutination activity of emerging Newcastle disease virus in Bangladesh

Characterization of hemagglutination activity of emerging Newcastle disease virus in Bangladesh

Purification and functional characterization of lectin with phenoloxidase activity from the hemolymph of cockroach, Periplaneta americana.

Lectins also identified as hemagglutinins are multivalent proteins and on account of their fine sugar-binding specificity play an important role in immune system of invertebrates. The present study was carried out on the hemolymph lectin of cockroach, Periplaneta americana with appropriate screening and purification to understand its molecular as well as functional nature. The lectin from the hemolymph was purified using ion-exchange chromatography. The approximate molecular weight of purified lectin was 340 kDa as determined by FPLC analysis. Rabbit erythrocytes were highly agglutinated with purified lectin from the hemolymph of P. americana. The hemagglutination activity (HA) of lectin was specifically inhibited by fucose. Glycoproteins also inhibited the HA activity of lectin. The amino acid sequences of the purified lectin revealed homology with amino acid sequences of allergen proteins from P. americana. Purified lectin showed the highest phenoloxidase activity against dopamine. The activators such as exogenous proteases and LPS from Escherichia coli and Salmonella minnesota significantly enhanced the PO activity of the purified lectin. Besides, the presence of copper and hemocyanin conserved domain in the purified lectin provided a new facet that insects belonging to the ancient clade such as cockroaches retained some traces of evolutionary resemblance in possessing lectin of ancient origin.

A novel beta-galactose-specific lectin of the tubeworm, Ridgeia piscesae, from the hydrothermal vent

Lectins are sugar-specific binding proteins or glycoproteins that play important physiological roles in cellular recognition and regulation. And they are also valuable in medicine and pharmacy. Tubeworm is the representative species around the hydrothermal vent in the deep sea. They have developed unique mechanisms to adapt to the harsh environment. In this study, a 1 092 bp cDNA, designed as rpgal, was first cloned and characterized from the tubeworm Ridgeia piscesae. Sequence analysis showed that RPGAL had low homology with the known galectin. And it had two homologous carbohydrate-recognition domains, which is the characteristic of the tandem-repeat type galectins. The RPGAL was successfully recombinant expressed in Escherichia coli and purified. Analysis of biological activity revealed that RPGAL was metal ion independent and it could agglutinate all the vertebrate erythrocytes tested. It was stable at 10–50°C and pH 5–10. And the hemagglutinating activity of RPGAL was strongly inhibited by D-Lactose and lipopolysaccharide. Although RPGAL had no effect on the microorganisms tested, it showed anti-tumor activity towards HeLa cells and HT1080 cells, which was accomplished by apoptosis. The study demonstrated that RPGAL was a novel galectin and provided a potential candidate for therapy of anti-tumor.

Elaboration of diagnostic means for detection antibodies to Newcastle disease virus

ObjectiveA test kit for the detection of antibodies to Newcastle disease virus(NDV) based on haemagglutination inhibition (HI) assay has beendeveloped and introduced into practice for the first time in Ukraine.IntroductionNewcastle disease (ND) is the most important infectious viraldisease of poultry. The world-wide economic loss from it is 2-3billion USD per year. ND is reportable to the World Organizationfor Animal Health (OIE). ND is caused by virulent strains of avianParamyxoviruses belonging to type 1. Industrial poultry farmingis rapidly developing in Ukraine. Ornithological fauna of Ukraineincludes about four hundred species of birds, 207 of which nestwithin its borders. The territory of Ukraine transits 3 out of 14transcontinental global migration flows. The wild birds are themain natural reservoir of ND agents. It is necessary to control theintensity of post-vaccination immunity in poultry and the timing ofrevaccinations. OIE recommends enzyme linked immunosorbentassays (ELISA) and HI test for these purposes [1]. However, it shouldbe noted that HI test, possessing high specificity and sensitivity, ismuch cheaper. Therefore, it is the excellent means for ND timelysurveillance.MethodsDuring the development of a new diagnostic kit, we used thereference strain “La-Sota”, which was obtained from the NationalCenter of Microorganism Strains of Ukraine. We have producedhaemagglutinating antigen using embryonated SPF fowl eggs and10-11 day incubation. A dilution of the virus was inoculated in0.1 ml volumes into the allantoic cavity and incubated at 35-37° Cfor 80-96 hours. For the purpose of NDV inactivation, we usedaminoethyleneimine at the final concentration of 0.1%. Positive serumwas prepared by immunizing 60-day-old chickens with live virus onceand by inactivated virus twice with an interval of 2 weeks. Negativeserum was obtained from healthy birds that did not contain antibodiesto NDV. The investigated blood sera were inactivated by heating(56 C/30 minutes). Samples of 1% suspension of chicken erythrocytesin phosphate buffered saline (pH 7.0-7.1) were used in HI tests.ResultsThe specific haemagglutination activity of the obtained antigenamounted to 10-11 log2.The test was performed using the 4HA unitsof the antigen. Positive control serum activity was in the range of 7-9log2. Negative control serum did not give results of more than 2 log2.The estimation of the quality indexes of the components of thediagnostic test-kit was performed using harmonized methods. In orderto examine sensitivity and specificity of HI test kits, antigens and serafrom commercial diagnostic kits were used. Also, certified negativecontrol serum and samples of International Standard sera were used,which were obtained from reference laboratories, namely againstthe following pathogens: Avian Influenza A (H5), Avian InfluenzaA (H7), Egg Drop Syndrome'76 Virus, Paramyxoviruses of 2 and3 serotypes, Reovirus, Avian Infectious Laryngotracheitis, AvianInfectious Bronchitis Virus, Mycoplasma gallisepticum, and NDV.In order to ensure a high degree of specificity for the antigen,special attention was given to the selection of a stabilizer for freeze-drying (the subject of a patent).Comparison between the national diagnostic test kit for HI andcommercial ELISA kit (IDEXX) in the evaluation of humoralimmune response to ND in vaccinated chickens was investigatedby examining of serum samples (n=152). Statistical analysis of datashowed that the correlation coefficient for the results of both tests was0.92. The relative sensitivity of HI test kit was 93.5% and the relativespecificity - 91.5%.The developed test kit was successfully used for the examinationof field samples. We developed regulatory documents, completed theprocedure of validation and registration in Ukraine of the commercialHI test kit for the detection of antibodies to NDV.ConclusionsThe use of the national standardized diagnostic test kit based onHI for detection of antibodies to NDV allows assessing the post-vaccination antibodies level that helps to maintain the disease-freestatus of the Ukrainian poultry industry with regard to ND.

Hemolymph haemagglutination activity of pearl oysters Pinctada fucata in post-operative care

Aquaculture ResearchVolume 48, Issue 11 p. 5690-5692 SHORT COMMUNICATION Hemolymph haemagglutination activity of pearl oysters Pinctada fucata in post-operative care Natsumi Sano, Corresponding Author Natsumi Sano natsumi5@bio.mie-u.ac.jp orcid.org/0000-0002-8485-792X Graduate School of Bioresources, Mie University, Tsu, Mie, Japan Correspondence Natsumi Sano, Graduate School of Bioresources, Mie University, Tsu, Mie, Japan. Email: natsumi5@bio.mie-u.ac.jpSearch for more papers by this authorTakashi Atsumi, Takashi Atsumi Mie Prefecture Fisheries Research Institute, Shima, Mie, JapanSearch for more papers by this authorShinji Tanaka, Shinji Tanaka Mie Prefecture Fisheries Research Institute, Shima, Mie, JapanSearch for more papers by this authorAkira Komaru, Akira Komaru Graduate School of Bioresources, Mie University, Tsu, Mie, JapanSearch for more papers by this author Natsumi Sano, Corresponding Author Natsumi Sano natsumi5@bio.mie-u.ac.jp orcid.org/0000-0002-8485-792X Graduate School of Bioresources, Mie University, Tsu, Mie, Japan Correspondence Natsumi Sano, Graduate School of Bioresources, Mie University, Tsu, Mie, Japan. Email: natsumi5@bio.mie-u.ac.jpSearch for more papers by this authorTakashi Atsumi, Takashi Atsumi Mie Prefecture Fisheries Research Institute, Shima, Mie, JapanSearch for more papers by this authorShinji Tanaka, Shinji Tanaka Mie Prefecture Fisheries Research Institute, Shima, Mie, JapanSearch for more papers by this authorAkira Komaru, Akira Komaru Graduate School of Bioresources, Mie University, Tsu, Mie, JapanSearch for more papers by this author First published: 02 May 2017 https://doi.org/10.1111/are.13370Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume48, Issue11November 2017Pages 5690-5692 RelatedInformation

Antitumor properties of a methyl-β-d-galactopyranoside specific lectin from Kaempferia rotunda against Ehrlich ascites carcinoma cells

A lectin was isolated from the tuberous rhizome of Keampferia rotunda by using different chromatographic methods with the molecular weight of 21±1kDa. The lectin contained highest percentage of leucine and lowest percentage of tryptophan residues as determined by LC–MS. The lectin agglutinated mice and human erythrocytes and the hemagglutination activity was inhibited by Methyl-β-d-galactopyranoside. The lectin did not lose its activity in the presence of urea but the activity abolished completely when treated with EDTA. The lectin exhibited its activity at the pH ranging from 6.0 to 9.0 and in a temperature range of 30–80°C. Antiproliferative activity was studied against Ehrlich ascites carcinoma (EAC) and U87 cell lines. No inhibitory effect was observed against U87 cell line whereas 43.7% cell growth inhibition was observed in vitro against EAC cells at 160μg/ml. The lectin was injected (i.p.) in EAC bearing Swiss albino mice at the doses of 3.0 and 6.0mg/kg/day for five consecutive days and 41 and 59% of EAC cell growth inhibition was observed, respectively. The cell growth inhibition was due to the induction of apoptosis in the EAC cells which was confirmed by cell morphological study, caspase-3 inhibitor and apoptosis-related gene expression.

Eutirucallin: A Lectin with Antitumor and Antimicrobial Properties

Eutirucallin is a lectin isolated from the latex of Euphorbia tirucalli, a plant known for its medical properties. The present study explores various characteristics of Eutirucallin including stability, cytotoxicity against tumor cells, antimicrobial and antiparasitic activities. Eutirucallin was stable from 2 to 40 days at 4°C, maintained hemagglutinating activity within a restricted range, and showed optimal activity at pH 7.0–8.0. Eutirucallin presented antiproliferative activity for HeLa, PC3, MDA-MB-231, and MCF-7 tumor cells but was not cytotoxic for non-tumorigenic cells such as macrophages and fibroblasts. Eutirucallin inhibited the Ehrlich ascites carcinoma in vivo and it was also observed that Eutirucallin inhibited 62.5% of Escherichia coli growth. Also, Eutirucallin showed to be effective when tested directly against Toxoplasma gondii infection in vitro. Therefore, this study sheds perspectives for pharmacological applications of Eutirucallin.

Healing activity evaluation of the galactomannan film obtained from Cassia grandis seeds with immobilized Cratylia mollis seed lectin

Galactomannan films from Cassia grandis seeds, associated or not with Cramoll 1,4, were used on topical wounds of rats for the evaluation of the healing process during 14days. All of the films were evaluated by cytotoxic assay, FTIR and lectin hemagglutinating activity (HA). Forty-five male rats were submitted to aseptic dermal wounds (Ø=0.8cm) and divided in groups (n=15): control, test 1, and test 2, treated respectively with saline, galactomannan film and film with immobilized Cramoll 1,4. Macroscopic evaluations were performed by clinical observations and area measurements, and microscopic analysis by histological criteria. Epithelial cell proliferation and differentiation was immunohistochemically assessed using CK14 and PCNA. The presence of CO peaks in the FTIR spectrum confirmed the immobilization of Cramoll 1,4 in the film, while the residual HA confirmed the stability of the lectin after immobilization with 90.94% of the initial HA. The films presented non-cytotoxicity and cell viability exceeding 80%. All of the animals presented re-epithelization around 10days, furthermore test 2 group showed a diffuse response at the stromal tissue and the basal layer associated with wounds completely closed with 11days of experiment. The results suggest a promising use of the films as topical wound curatives.

Salmonella mediated the hemagglutinating virus of Japan-envelope transfer suppresses tumor growth.

Salmonella can target to tumor microenvironments after systemic treatment. The hemagglutinating virus of Japan-envelope (HVJ-E) induced apoptosis in tumor cells without toxicity in normal cells. Current HVJ-E therapeutic strategies, aimed at using HVJ-E for intratumor treatment, have shown great promise in animal models but have achieved only limited systemic treatment. The purpose of this study was to investigate the modulation of the anti-tumor efficiency of HVJ-E by coating the particles with poly (allylamine hydrochloride) (PAH), designated as P-HVJ-E. Treatment with P-HVJ-E resulted in decreased hemagglutinating activity and maintained tumor cell-selective apoptosis and anti-tumor immunity. The use of Salmonella as a coating for P-HVJ-E (PHS) enhanced the antitumor activity and maintained the tumor-targeting activity. Treatment with PHS resulted in delayed tumor growth in tumor-bearing mice. Furthermore, a Western blot assay of the tumors revealed that HVJ-E targeted to the tumor after systemic treatment with PHS. These results indicate that Salmonella coating viral particles may provide a new approach for tumor therapy.

Molecular Dynamics Simulation of the Influenza A(H3N2) Hemagglutinin Trimer Reveals the Structural Basis for Adaptive Evolution of the Recent Epidemic Clade 3C.2a

Influenza A(H3N2) has been a major cause of seasonal influenza in humans since 1968, and has evolved by antigenic drift under the constantly changing human herd immunity. Increasing evidence suggests that the antigenic change occasionally occurred concomitant with the alterations of the N-glycosylation site profile and hemagglutination activity of the virion surface protein hemagglutinin (HA). However, the structural basis of these changes remains largely unclear. To address this issue, we performed molecular dynamics simulations of the glycosylated HA trimers of the A(H3N2), which has a novel pattern of Asn-X-Ser/Thr sequons unique in the new A(H3N2) epidemic clade 3C.2a and is characterized by attenuated ability to agglutinate nonhuman erythrocytes. Comparison of the equilibrated structures of the glycosylated HA trimers with and without the 3C.2a-specific mutations reveals that the mutations could induce a drastic reduction in the apical space for the ligand binding via glycan-shield rearrangement. The results suggest that the 3C.2a strain has evolved an HA structure that is advantageous for evading pre-existing antibodies, while also increasing the ligand binding specificity. These findings have structural implications for our understanding of the phenotypic changes, evolution, and fate of influenza A(H3N2).

Purification and characterization of Cc-Lec, C-type lactose-binding lectin: A platelet aggregation and blood-clotting inhibitor from Cerastes cerastes venom

In this study, we reported for the first time the biochemical and structural characterization of Cc-Lec, a C-type lectin purified from Cerastes cerastes venom by affinity chromatography. This lectin was homogeneous by SDS-PAGE, and was shown to be a 34 271.59Da polypeptide by Electrospray mass spectrometry MS-ES-TOF. Its identified sequence of 160 amino acids corresponding to one subunit, revealed a high identity with other related proteins. Cc-Lec modeled 3D structure appeared as homodimer cross-linked by one disulfide bridge. Cc-Lec exhibited a calcium dependent hemagglutinating activity against human group O erythrocytes. Cc-Lec inhibited platelet aggregation induced by ADP, arachidonic acid or fibrinogen suggesting its interaction with their specific receptors namely P2Y1 and/or P2Y12, GPIIb/IIIa and TPα respectively. Cc-Lec was not lethal for mice until 10mg/kg administered by i.p. route. The lectin displayed a lasting anticoagulation on mice plasma even two days post-injection. This anticoagulation seems to be related to its interaction with coagulation factors Xa and IXa. Therefore, Cc-Lec prevented FXa amidolytic activity with Km=4.3310−4μg/mL and ki=14.4μg/mL. It seems to interact with these targets through CRD domain which could make it a good target as a pharmacological promising molecule in thrombosis diagnosis and therapy.